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cmt1_gw

Sears Kohler 22 V-Twin CV22S engine wont stayrunning

cmt1
14 years ago

Hello All, New Lady on the site and not a small engine repair expert but need to try to fix it myself - please bear with me.

I have a problem..my craftsman (917.273080 model num, Sears Kohler 22 V-Twin GT CV22S 46")it will fire up if I pore gas into the carb 'cup' but wont stay running.

Here is what I have done to date... replaced the battery, fuel pump, fuel filter, air filter and sleeve and both spark plugs. I bought carb cleaner and sprayed it into the 'holes' without removing any parts. (BTW I put a fuel filter from sears ... salesman said the generic version would work)

Downloaded the manual but the critical diagram pgs are light to read. I will work the carb if someone can give me a little direction. NOT afraid to try! Thanks to anyone can help someone who is Desperate to mow my 2 acres after all our rain, major grass growth, and neighbors who would appreciate a little yard attention. lol

Comments (39)

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    BTW I changed the oil and filter....

  • rcbe
    14 years ago
    last modified: 9 years ago

    quote:"(BTW I put a fuel filter from sears ... salesman said the generic version would work)"

    Ahuh. Kohler engines often need specific fuel filters. Best to get the right one installed - try kohler #25 050 07-s for your cv22.

    M/w, take your fuel line loose at the carb. Remove spark plug wires and crank engine over. Should have fuel spurting out. If not, troubleshoot fuel delivery sys.
    If so, check fuel shutoff solenoid usually located at bottom of card with one wire running to. Solenoid plunger should not be sticky and should make a "click" when ignition sw turned on.If not, clean/replace solenoid.
    If Ok, remove carb - disassemble, noting what goes where - and soak/clean thoroughly with carb cleaner. Use a fine piece of stranded copper wire or such to clean the really small passageways and then blow everything clean with air.
    Reassemble using good/new gaskets.
    If engine still acts up, post back with updated result/observations. Good luck.

  • mownie
    14 years ago
    last modified: 9 years ago

    "remove carb - disassemble, noting what goes where" If you have a digital camera, shoot lots of pictures of everything before and during the "dis-assembly". Every item should be "shot" before you remove it, and again after you remove it. This way you are less likely to "forget" which way it came off etc. when you get ready to put it back.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    Ohh Thank you so very much!!!! I will try tonight or in the morning and post further results.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    per rcbe ...(If so, check fuel shutoff solenoid usually located at bottom of card with one wire running to. Solenoid plunger should not be sticky and should make a "click" when ignition sw turned on.If not, clean/replace solenoid.)

    Hello folks, I have good fuel going to the carburetor; however, I need assistance with ensuring the location of the solenoid...is it at the bottom of the carb attached with a large nut and a red (in my case) wire coming out of it???? Thanks

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    found pic of solenoid through reasoning and removed, all looks good - spring, and components are good.

    cleaned carb with cleaner but without removing and used a can of compressed air to clean and blow all holes. having problems removing screw at top. It is really on there but will work it out some way so I can completely remove/clean carb.

    so far I am puzzled

    One other so I know -- how many turns for the fuel adjusting needle and the speed adjusting screw?

  • mownie
    14 years ago
    last modified: 9 years ago

    "a large nut and a red (in my case) wire coming out of it?"
    Yes, that is a reasonable description of the solenoid valve. Remove the solenoid valve from the carb. Some gasoline might/will run out of the bowl, so place a rag or paper towels under the carb to catch the small amount that drains out. After you have the solenoid valve removed from the carb, you will see a "plunger" or valve "stem" protruding from the "carb end" (threaded end) of the assembly. Press on the end of this "stem" with a finger and try to push it into the solenoid body. It should "push in" easily AND "pop" back out when you remove the finger pressure. If it is "hard" to push in, or does not pop out afterward, you need to clean the solenoid with carb cleaner. I fill bottle cap (soft drink cap) with carb cleaner and stand the solenoid on its threaded end in the cap and "soak" it for about 30 minutes. After it has soaked for a while, spray around the threaded end where the plunger goes in and try pushing the plunger in again. Once you get the plunger "freed up", push it in and let it pop out numerous times and frequently spray more carb cleaner around and into the end to flush out all the varnish and "grit" that may be in there. If the solenoid plunger feels and acts correctly (pushes in and pops out easily) when you first remove the solenoid from the carb, You will need to check the electrical operation of the solenoid. To "do an electrical test", you will need to use a 12 volt battery (the tractor battery is good) and some "jumper cables" or boost start cables. For the "pros" and experienced folks reading this, I am suggesting "jumper cables" be used in order to place cmt1 (or anybody else) away from the battery. I have no way of knowning how much working experience with jumper cables you have, so I'm going to be very basic with the procedure. Lay your jumper cables out on the ground (or floor) and make sure that the end clips on the ground are not "touching together". Attach the other pair of end clips to the tractor battery as follows: RED clip onto the + post of battery, BLACK clip onto the - post of battery (battery has the + & - symbols on the battery near the posts). Now, go to the end clips lying on the ground. Open the BLACK clip and put the solenoid metal body into the jaws of the clip so that the metal jaws of the clip make contact with only the metal body. Be careful not to let the end clips touch each other at any time. Let the clip close on the body of the solenoid and lay the clip on the ground so that the plunger is visible to you and is not touching the ground or other object. Next, take the RED clip and touch it to the wire terminal on the end of the red solenoid wire. The solenoid plunger should be "sucked in" or withdrawn into the solenoid about 3/16 inch or so. If the plunger does not withdraw into the solenoid when you touch the red wire to the red clip, push in on the pluger very gently with a finger tip while the red wire touches the red clip (you can just open the jaws of the red clip and let the jaws hold the terminal of the red solenoid wire). If the solenoid is good, there should be a point when you are pushing on the plunger that the "magnet" of the solenoid will "grab" the plunger, pulling it the rest of the way in and holding it in until you separate the red solenoid wire from the red clip. If the solenoid DOES NOT pull in, and hold in, the plunger......your solenoid is defective. All this assumes you have a "good, working set of jumper cables. If the solenoid DOES work properly during this test, you will need to check whether the wire on the tractor that the red solenoid wire connects to.....is "getting current" when the ignition switch is in the run position. If everything about the solenoid and its wiring is OK, you will need to go to the next steps in carb cleaning. Post back for more instructions.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    mownie Thank You i did as per your Excellent instructions...the solenoid worked perfectly no hesitations at all sucked it in as soon as I touched the red ends together (so to speak) so now I have tried with all my might to remove the ground(?) screw at the top of the carb without success. Looks as if I will need to drill out the screw as I have successfully stripped it. bummer
    once that is done i will remove the carb and clean appropriately. Also will be going to the store (hopefully available) to find both gaskets...from what I can see the 'rear'gasket is going to need replacing. I have the part number for the 'front' gasket but cannot find the rear(?) gasket number.
    Any other ideas are appreciated...Thanks again mownie

  • mownie
    14 years ago
    last modified: 9 years ago

    I'm not personally familiar with that "ground screw", but I do understand screws getting stuck/frozen and then "stripped' or wallowed out (tool bit provision). Does this "ground wire" serve the fuel solenoid? Or is it a "ground wire" for other something? "Drilling out" is not exactly what I recommend here because you may end up with more to fix than you bargain for. If you choose to "drill out", you may destroy the threaded hole or even "break on through" and really mess up the carb. If you are only going to "drill off" the head of the screw (in order to release the wire eyelet terminal), that's ok, but you might be better off to just cut the ground wire near to the terminal end at the ground screw and leave the screw in the carb. Then you can repair the wire by splicing an extension wire onto the remaining ground wire and finding a different "ground location" to re-attach the wire to. You can utilize any convenient "bolt or screw" that connects to the engine or chassis as a new ground attaching point. Avoid using a bolt or screw that secures a "gasketed" component or a bolt that goes through some type of rubber insulator. You would need to choose the new bolt/screw location first and then add enough wire to the OEM wire and select a new terminal of the right eyelet diameter to fit the new bolt/screw.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    The wire is green and is on top of the carb. I don't believe it is a ground as it would not make sense... not sure though...

    I thought of the same idea of cutting the wire and re attaching once done with the carb and after a thorough exam.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    Hello, hope all are having a great wkend. I am still in a pickle with this tractor. Finally got the carb gaskets and I just removed the carb, cleaned, blew it out, verified all parts are in good order. put the thing back together and it is doing the same thing.... if I pour gas into the carb bowl it will stay running - once that is out the engine stops. any further suggestions>>I am in desperate need of ALL recommendations. Thanks so very much!

  • rcbe
    14 years ago
    last modified: 9 years ago

    Romove fuel line at carb. Remove spark plug wire(s). With assistant's help, crank engine. Fuel should be pumped out of disconnected hose. If not, you have a fuel delivery problem somewhere from the hose back to the fuel tank. If fuel runs out well, then it's the engine carb starting with that shutdown solenoid or the engine's ignition messed up.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    mownie had me test the solenoid and all checked out fine. the plunger is clean and with a 12v 'jump' from the battery reacts immediately. The tractor will stay running if I continue to pour gas into the carb 'bowl'. we tested all the fuel lines and the filter again. (blew on them and once again took out the solenoid fuel flowed from the bottom. I am truely frustrated...at this point if I call someone it is going to be something simple....murpheys law of my luck LOL :)

  • mownie
    14 years ago
    last modified: 9 years ago

    Not an ignition problem if it runs so long as you "pour gas" into the carb. cmt1, when you cleaned the carb, did you spray carb cleaner into ALL holes, passages, and orifices everywhere on the carb, inside the bowl area, followed by probing the same with a very fine, stiff wire? And finish up by spraying through all the holes again with cleaner and compressed air? What about the carb fuel inlet hose connector. That passage needs to be clean and the needle valve in the inlet passage must not be stuck in its valve seat. From what you are saying (runs on poured gas), the indications still point to point to lack of fuel. When you say you say you "pour gas into the BOWL", I believe you mean you are pouring gas into the THROAT of the carb. The BOWL is on the bottom of the carb, the THROAT is where air enters the carb (after passing through the air filter). Or if you really are pouring gas into the BOWL, and then the engine runs til the amount of gas in the bowl is consumed........that would indicate that at least the jets are probably clean (and carb may be ok). If this last scenario is what you are actually doing (filling the bowl from a bottle), the problem would seem to be that gasoline IS NOT being delivered to the carb. Please try to clarify by the remarks I have made.

  • cmt1
    Original Author
    14 years ago
    last modified: 9 years ago

    'I believe you mean you are pouring gas into the THROAT of the carb. The BOWL is on the bottom of the carb, the THROAT is where air enters the carb (after passing through the air filter)'

    Mownie, I am pouring into the 'throat' cup on the front 'plate' that the air filter goes/attaches ... on the front of the carb.

    I would attach a pic but I don't know how...

  • mownie
    14 years ago
    last modified: 9 years ago

    cmt1, I have the manual now, I will prepare something (picture) and post it later tonight. I think your problem is that fuel is NOT GETTING TO (or INTO) the carb. Hopefully we will get this whipped.

  • mownie
    14 years ago
    last modified: 9 years ago

    Hopefully, 2 pictures. {{gwi:323759}} {{gwi:323760}}

  • mownie
    14 years ago
    last modified: 9 years ago

    cmt1, have you taken the fuel bowl (item 11 above)? If so, was it "full" of fuel? If the bowl had little or no fuel in it, fuel is not getting to the bowl area, or it is not getting to the carb. If the bowl is empty of fuel, the fuel pump may not be delivering fuel to the carb. I am going to post a picture of the fuel pump with instructions on how to test it. That will be in another post. If the fuel bowl WAS full of fuel when you removed it, fuel is getting into the carb & bowl, BUT........it is not being drawn out of the fuel bowl. If the bowl is full but the engine still will not run, the MAIN JET is obstructed. The main jet passage is where you need to clean with spray carb cleaner and probe with a fine stiff wire. Now I tell you another dirty little secret. The very small "slow jet" or "pilot jet" is probably clogged too (that was the dirty little part). The main jet is the bigger of the two and it is directly in line with the solenoid plunger. The slow jet is off to one side of the main jet. Refer to your manual for picture.

  • mownie
    14 years ago
    last modified: 9 years ago

    In this photo you can see the names of the three hose nipples on the fuel pump. Make sure that the hoses on your engine are connected just like in the photo. {{gwi:319028}}
    The "inlet line" or hose must be the hose from the fuel tank. The outlet line goes to the carburetor. The pulse line connects to the pulse vacuum nipple or port on the engine. If the inlet line and the pulse line have been "transposed", the fuel pump will not function. So check how the hoses are connected first. Next, to check the pump for output, you need a short piece of hose (the same as the fuel hose or similar) about 12 to 18 inches long. You will also need a clear plastic soft drink bottle and a helper person. Remove the fuel hose from the outlet nipple of the fuel pump and connect your short piece of test hose to the outlet nipple. Place the open end of the test hose into the bottle. Have the helper crank the engine for about 10 seconds (and no more than 10). If the fuel pump is pumping adequately, it should have pumped enough fuel in 10 seconds to equal (or exceed) the volume of the fuel bowl, or about 1/4" to 1/2" deep in a common 20 ounce drink bottle. If the fuel pump does not pump near this amount (or does not pump at all) check that the pulse hose is connected to the pulse nipple or port on the engine, and that the hose is not clogged or broken, or split open. If that hose checks good, trace the inlet hose (pump to filter to tank) for being pinched or kinked. Make certain that the fuel filter is pointing the right way, should be an arrow on it somewhere and the arrow points toward carb.If the pump is delivering fuel adequately, check the outlet hose (pump to carb) for a kink or pinch or clog. If the hose turn out OK, the carb needle valve is stuck or clogged (this is presuming that all other carb issues have been checked/corrected).

  • hemmi101
    14 years ago
    last modified: 9 years ago

    I'm following this with interest. My Kohler cv22s has a carb prob. The engine runs OK with choke part way on but almost immediately dies when I remove choke
    I have checked fuel pump flow--seems ok. Replaced filter.
    I have got the solenoid working--it was stuck but in the "on" position-so this shouldn't have mattered (right?) Works fine now.
    From the picture the red arrow "possible obstruction site" was clean, and I blew air in but no wire or jet cleaner.
    there were a few flakes of something in carb float chamber. Otherwise had fuel in it and basically clean.
    Float valve is clear.
    I removed #4 passage cover (from illustration) intent on further blowing things out. However I was chicken to destroy gasket. Am I wise to remove, clean whatever I find,and make another gasket? Is there anything special about the gasket or can I make one? (sears wants $17 for one.)
    I'm ready to order a carb kit for $50 shipped but being Scotch I thought I would try a cheaper clean out. If anyone has an idea I would appreciate. Otherwise will bite bullet, buy kit and hope it does the trick.
    PS I ran some HEET gas drier and a bit of stp carb treatment through the rig with no particular effects. thanks, Earl

  • mownie
    14 years ago
    last modified: 9 years ago

    ***"got the solenoid working--it was stuck but in the "on" position-so this shouldn't have mattered (right?)"***
    By "on position", you mean the plunger was "pulled into" the solenoid....is that what you saw? Also, ***"From the picture the red arrow "possible obstruction site" was clean"***
    Go look at the picture again, there are two arrows and two "possible obstruction" sites. One is in the passage above the solenoid plunger, the other is in the seat area where the needle valve is supposed to seal. That seat area is already a somewhat "restricted" path and any debris that gets hung up there will only cause less fuel flow into (and out of) the carburetor. If you got the "passage cover" off without damaging the gasket, try spraying some carb cleaner on the gasket to see if that will make it turn loose. I would not fear trying to make a new gasket if you damage the old one, it does not appear to have a complex shape. Just make sure the gasket stock you use is rated for gasoline and/or diesel fuel, and is as thick as the old one. Do not be tempted to use RTV (silicone) in this application. It will not perform in the presence of gasoline.

  • hemmi101
    14 years ago
    last modified: 9 years ago

    Thanks mownie. Indeed the plunger was pulled into the solenoid. It freed right up and seems to work fine now. The float valve seat is clean but I will focus on the area above solenoid. Will go into passage cover and if needed build new gasket.

  • mownie
    14 years ago
    last modified: 9 years ago

    hemmi, also notice item #2 in second picture. That is the IDLE FUEL adjusting screw. The circuits/passages involved with this screw comprise the idle circuits. There are at least 3 similar names used throughout the world for this "control area". The ones I'm familiar with are: (1)Pilot fuel circuit (2) Idle fuel circuit (3) Slow speed, or Low speed fuel circuit (and the term "speed" is in reference to engine RPM, not actual "ground speed"). Before you remove this screw (to clean out the "circuits"), you need to make a written notation of the "setting" of the screw. To do this, you need to count the number of turns, and "fractions" of turns, required to turn the screw "clockwise", until it seats. DO NOT "tighten" the screw into the carb, you only want to "touch bottom". After you have written down the turns and fractions of turns (typically 1 & 1/4 to 1 & 1/2 turns) you can turn the screw "counter-clockwise" to remove it from the carb body. Clean the screw tip with carb cleaner. Spray a "liberal" dose of carb cleaner into the screw hole and into all the other holes and passages that you exposed when you removed the "passage cover" (item #4). After you are completly finished cleaning the carb, run the screw in clockwise until it seats, then back it out the exact number of turns you wrote in your notes. You ideally should remove the main jet from the carb when cleaning out all the circuits on a carb because on some carbs, the main jet DOES NOT completely "fill up" the bore it threads into. On some carbs, the main jet threads in and seats against a "stop ledger" (smaller diameter than threaded portion of hole), or in some cases, the jet itself is configured "like a capscrew" and seats on the outside edge of the threaded hole. Both cases will leave a "large" open cavity between the jets and the main delivery tube (goes to the carb venturi area). I have cleaned carbs that were "already cleaned", and found trash in this cavity that had not been "evicted" by the "first person" who "cleaned" the carb.

  • diyer4me
    14 years ago
    last modified: 9 years ago

    Did this ever get resolved? I have a Scag SSZ with a Kohler 22CVS that just developed a very similar problem. Starts right up and then shuts down like the key has been turned off. I have isolated the problem to the carb solenoid losing power upon releasing the key switch from the start position. If I run a 12 volt jumper to the solenoid, it runs like it should. What's wrong? I though the ignition switch was bad and replaced it. Of course it couldn't be that easy. All of the lockout switches function or the engine will not even turnover. The link is to the SCAG web site for the manual. Page 32 is a wiring diagram. Please help.
    Thanks!

  • rustyj14
    14 years ago
    last modified: 9 years ago

    Well, let me say this:
    Our friend, Mownie, is a really good guy to have in this forum! His clear instructions have me sitting back in awe!
    Thanks, Mownie, for helping out those of us who need good advice and help with our problems! Your advice is clear and helpful, so much so that a cook or a baker could repair his or her mower or tractor!
    by: Rusty Jones, the Mower Man.

  • mownie
    14 years ago
    last modified: 9 years ago

    diyer4me, I wonder if your SCAG machine has the Kohler Oil Sentry engine "protector" shut down feature. I looked at the SCAG manual in your link (electrical diagram) and I find nothing in the SCAG built circuitry that could remotely result in the problem you have (loss of 12VDC to fuel solenoid). But, I went to the Kohler manual and I see that engines that feature the Kohler Oil Sentry engine protection system, DO HAVE circuitry that can "kill" the engine when low lube oil pressure occurs. Any shut down system that uses "low oil pressure" as a condition to "kill" the engine, must also feature an over ruling circuit that will allow the engine to "begin running" on start up BEFORE the engine begins to build oil pressure. The "start up" scenario with an engine that has the system plays out like this (and I'm only going to describe the shut down related circuitry: Ignition switch is turned on. Current is sent from the ignition switch, into the vehicle wiring harness, to arrive at the "shut down module" (likely, the "module" may also have other functions, but let's focus on the low oil pressure portion of duties). At this point in time, the current that would normally be "forwarded" out of the module and on to the fuel solenoid, is interrupted.......because the engine has "zero oil pressure", the module is fulfilling it's assigned duty. Next, you turn the ignition switch to the "START" position. This action will send current into the starter solenoid control circuit. The shut down module receives current from this circuit, or, this circuit may "bypass" the shut down module altogether, depending on how an OEM configures everything. Either way, the starter solenoid control circuit provides "momentary energizing" of the FUEL solenoid........to allow the engine to begin running in the "absence of oil pressure". Next, the engine starts up and begins running on its own power, so you turn loose of the ignition switch and the key returns to the run position. All current that WAS being fed to the starter solenoid control circuit, is now gone! BUT, because the engine now has oil pressure, the shut down module has "changed its mind" about depriving the fuel solenoid of 12VDC, and the engine is happily running, awaiting your next command. NOW, go back through the above sequence of events, except THIS TIME, the shut down module, or the wiring (including any diodes) from the module to the fuel solenoid...............has an "open circuit". This set of circumstances will cause the engine to "fire up and run" ONLY WHEN THE IGNITION SWITCH IS IN THE "START POSITION"!!!!!!!! As soon as you turn loose the key, the fuel solenoid circuit goes "dead", and the engine dies. Click to the Kohler service manual (link below) and study the Oil Sentry System in the LUBRICATION chapter of the manual. The Oil Sentry diagram indicates there are 2 diodes in the circuitry serving the fuel solenoid. The diodes are there to make sure that the 2 separate circuits that ARE CAPABLE OF energizing the fuel solenoid, NEVER, EVER connect together (electrically, that is). Maybe I should say that the shut down "over rule" function is furnished by current in the starter solenoid control wiring and is only present when the start position of ignition switch is selected. Anyhow, check and see if your CV22 has the Oil Sentry (it might be "standard" for all I know). Browse through the manual and you will see the Oil Sentry pressure switch (sending unit) is located directly beneath the carburetor. This Oil Sentry pressure switch is only for the Oil Sentry shut down system. The engine oil pressure warning light is controlled by a separate and independent oil pressure switch. Let us know what you find.

  • diyer4me
    14 years ago
    last modified: 9 years ago

    Thanks for your quick response Mownie. After staying up till 1:30 am this morning reading post on this forum, I hoped you might respond.

    There is no Oil Sentry on my Scag. There is a 1/8" NPT plug located just below and to the left of the carb. solenoid. I have read through an excellent service manual for free from Kohler. It does not mention the carb solenoid situation I have. I'm almost ready to wire directly to the solenoid like an accessory. To my knowledge the Scag has safety switches in both steering controls, seat switch and pto switch. I checked seat switch with ohm meter, Ok. If I move steering controls out of neutral no start, same with pto. It doesn't make sense to me.

    Thanks,
    Dave

  • mownie
    14 years ago
    last modified: 9 years ago

    ***"There is no Oil Sentry on my Scag."***
    OK, that settles that possibility. Still, when a fuel solenoid is used on an engine, it is there to prevent UNBURNED fuel from being transported out of the engine as the engine spins to a stop when being shut down. In order to ensure that the last little bit of fuel leaving the main jet after the fuel solenoid closes (during shut down), ACTUALLY BURNS in the engine, the ignition system must keep on sparking until the engine comes to a complete rest. Kohler insinuates that a "kill wire" is present that stops ignition spark in order to shut down the engine, but the Kohler illustrations also imply that there are diodes related to the fuel solenoid circuit. The idea of killing the ignition spark to shut down an engine was the normal way to go...........years ago. But with emissions standards getting ever more restrictive, that method is "out of style". So, looking at the Kohler manual, I can't draw a conclusion as to which, if either, method applies to your Kohler engine!!!! Try this as an experiment. First, unplug the starter solenoid control wire from the starter solenoid (Scag says it is green). Tape the wire end if there is a chance of shorting that wire while it's disconnected. Using a 12V test light, with the ignition switch turned to RUN, check all the terminals on the back of ignition switch. Make a sketch of the terminals and indicate which of them are "hot" in the RUN position. Turn the ignition switch to the start position and hold it there while you check to see which of the terminals are "hot" in the start position. What we are trying to determine here is whether you are "losing" 12V power to the fuel solenoid circuit AT THE IGNITION SWITCH when the key returns from START, or if the loss of 12V power is happening elsewhere in the wiring. Things to note here are: Which terminals are HOT when the ignition switch is OFF. Which terminals are HOT when the ignition switch is turned to RUN. Which terminals are HOT when the ignition switch is turned to START. My opinion is that the SAME terminals of the ignition switch that are HOT in the RUN position........should also remain HOT in the START position with the starter control circuit BECOMING HOT in the START position only. If we have to, I can post a sketch that sort of depicts the posts shown by Scag, and then you can fill in the info of which hot & when.

  • diyer4me
    14 years ago
    last modified: 9 years ago

    I will check what you suggested. I have the key switch wiring diagram. There is a Bosch 25 amp fuse that has a group of wires going into it. Is there a way to test it? I think there are 5 terminals on it. On the Kohler wiring schematic adn tracing the red wire from the carb solenoid it looks as though a red wire from the starter solenoid to a fuse links up to the wire from the carb solenoid. Are they connected? Due to the shrouds and wiring protective coverings on wiring harness, it is difficult to trace the wiring. Trying to use ohm meter to trace wiring.

  • mownie
    14 years ago
    last modified: 9 years ago

    ***"On the Kohler wiring schematic and tracing the red wire from the carb solenoid it looks as though a red wire from the starter solenoid to a fuse links up to the wire from the carb solenoid. Are they connected?"***
    That (if I understand what you see) is what I was referring to as one of the requirements for being able to get an engine started, IF.....a low oil pressure shut down system is featured. The fact that you don't have the "full blown" Oil Sentry option DOES NOT mean that some of the neccessary wiring might be in place in all applications. Don't forget, the Kohler illustrations depict diodes in nearly every drawing of the wiring for the fuel solenoid. I just wish they were more thorough in describing the relationship between the components, electrically. I have a feeling that Kohler uses a "module" of sorts to acutually feed 12V to the fuel solenoid instead of feeding it directly from the ignition switch.
    ***"There is a Bosch 25 amp fuse that has a group of wires going into it. Is there a way to test it?"***
    Are you saying that YOUR SCAG only has a single 25 AMP fuse??
    In the Scag manual diagram, I see two fuses, neither of which is given an amp rating (in the diagram).
    This might end up being a case of "Manual does not accurately fit the actual machine." I've run into that a few times in my life.
    Keep posting and I'll keep studying the two manuals. I can tell you this much: I wouldn't give Kohler or Scag any awards for developing a "comprehensive" manual in the electrical area.

  • diyer4me
    14 years ago
    last modified: 9 years ago

    I found the problem! When I was looking under the panel checking wiring, I found a hidden fuse holder with two 20 amp blade fuses. One of them was blown. Replaced it and works great. I have owned this Scag for almost 11 years and have read everything about this mower in the manuals and never new of the existence of these two blade fuses. There are two other Bosch fuses mounted on the engine. As you said, no awards for a comprehensive manual. Thanks for all of your help. I wonder if a similar fate befell the originator of this post?? Hidden fuses! Who knew!

    How do you check for recent post to this forum?

    Thanks again! Great forum.

  • mownie
    14 years ago
    last modified: 9 years ago

    diyer4me, I'm glad you were able to "sleuth out" the culprit. I still believe there is more to the circuitry than Kohler or Scag is presenting in their schematics. You just don't have 12VDC present (at fuel solenoid) while cranking, and then have it disappear a moment later.....for no reason.
    ***"I wonder if a similar fate befell the originator of this post?? How do you check for recent post to this forum?"***
    You mean you want to check up on cmt1 to swap notes??
    HAH! What you see in the forum, IS THE MOST RECENT!
    If everybody, that ever posed a question, or posted a problem to this forum........actually revisited their threads consistently, Garden Web would probably need a lot more webspace and band width to function at all. If you want to get an answer about how the OP resolved (or didn't) their problem, you could try one of those "Psychic Hot-lines" or something. We sure didn't get the answer here :^)

  • diyer4me
    14 years ago
    last modified: 9 years ago

    On pg. 32 of the Scag manual, the schematic shows two fuses in the lower right hand corner. However, you can't trace the fuses to the carb. solenoid because the carb. solenoid is not identified on the schematic. There is reference to a engine harness but still.... that's a stretch to link it to the solenoid. Page 30 you can see the fuses and holder. But a search of the manual and a Google search yielded no mention of checking for a fuse relative to a fuel shut-off solenoid or carb. solenoid. Who would have thought that the carb. solenoid would be energized by the start position and then current passed through a fused path.

    Hey, thanks again for helping and being a sounding board.


  • mownie
    14 years ago
    last modified: 9 years ago

    You're welcome. I was as perplexed as you with the "lack of" detail regarding how and when the fuel solenoid became energized. There is only one other circumstance I can liken YOUR situation to (engine acts like it wants to run when cranking, but dies when key is released from START position).
    Back in the '40s, '50s, and early '60s,, some automotive engine OEMs employed a "ballast resistor" in the ignition coil circuit. This "ballast resistor" was placed in the ignition coil circuit so that the normal system voltage, was cut by 50% before reaching the ignition coil. This meant that on a vehicle with a 12 volt electrical system, only 6 volts was fed to the ignition coil from the RUN position of the ignition switch. 6 volt systems cut the power to 3 volts. The most compelling reason for having to "rig up" the coil feed this way was due to the woefully inadequate batteries, switches, wiring and other things electrical, of that time. Mainly, it was the "weak" automotive batteries of the time that had to be "compensated for". Here's why: All applications that utilize a battery to power a cranking motor, will experience a dramatic "system voltage drop" throughout the entire electrical system during cranking. The "drop" is caused by the very heavy "current draw", or LOAD, of the starter. The voltage drop causes the ignition coil "sparkability" to diminish significantly. Add to that, a good frosty morning where the battery is cold and even weaker. Factor in further that the starter itself has worn brushes and sticky bushings and you will have so much current draw.....you might not even get a spark out of the coil. Enter the wizards of yesteryear (uhh, maybe they were just engineers). They developed a method to assure good sparks from the coil during cranking. The idea was to use a 6 volt rated ignition coil on a 12 volt system instead of the usual 12 volt rated coil (3 volt coil for 6 volt systems). But how can you do that? Wouldn't a 6 volt coil "burn up" if you powered it with 12 volts? Yes, it would........but not if you feed the normal RUN position power through a "ballast resistor" to reduce 12V to 6V before it reaches the coil. HUH? The "key" to how this arrangement assured dependable starting was in adding a SEPARATE circuit that would "BYPASS" the resistor while the starter was engaged. Bypassing the resistor meant that the ignition coil would be fed a "higher voltage" (in spite of system voltage drop) when cranking, than in normal running mode. After the engine "caught on", the starter was disengaged and the bypass circuit disabled. The current feeding the coil once again flowed through the ballast resistor and the 6 volt rated coil was safe from burning up. It was somewhat common in those days to confront a vehicle that acted similar to this Scag. (It wants to start while cranking, but dies when let go of key.) Most of the time, that particular problem would be due to a failed ballast resistor. But those systems had some other shortcomings. Sometimes you would find a vehicle where the owner would complain of "it just cranks and cranks and cranks, but if you turn the key loose, it might start up at that moment. THIS condition was due to the BYPASS circuit being open for some reason. OEMs accomplished "BYPASS" in different ways. Some added an extra post to the ignition switch that would power the bypass circuit during cranking. Other OEMs added an extra wire to the starter solenoid that powered the bypass circuit during cranking. When something became open in the bypass circuit, the coil would only be fed the reduced voltage. Then you were right back to the situation before the ballast resistor systems came into use. Advances in battery, ignition, starters, and conductors in general, made the use of ballast resistor systems disappear in the 1970s (except for some industrial applications). Oh yeah, magneto ignition systems were unaffected by voltage drop in the vehicle electrical system because they are "self contained spark generators".

  • hemmi101
    14 years ago
    last modified: 9 years ago

    thanks Mownie for advice which led to final success. Carb works fine now as the result of disassembly and soaking in carburetor cleaner, a blowout, and further solenoid fiddling.
    Somewhere along the line some dirt entered solenoid and lodged in jet, preventing the engine from running at all. Now on reassembly engine runs normally. Thanks

  • mownie
    14 years ago
    last modified: 9 years ago

    hemmi101, this is good news for sure. A "real feel good day" in helping out the "Poster family". Now if we could just get cmt1 to call home!! :^)

  • eroy2525
    14 years ago
    last modified: 9 years ago

    I have a scag ssz with the kohler 22cv. It recently quit running. Blew the fuses under the seat. Wound up taking it to the scag dealer. $187 later they found a burnt wire under the engine cowling. Brought it home and mowed once A-ok. Next time it started fine ran for a few minutes then started to sound like it was choked. Sputtered and died, shot flames out the exhaust pipe. Pulled the air cleaner, full of gas in the bowl. Sopped it out and tried to restart. Immediately filled the bowl with gas again. Could this be caused by the gas solenoid? Either stuck or another burnt wire? Refuse to take it back to dealer if there is any way I can fix it. Any advice appreciated before I start removing sheetmetal. Thanks.

  • rcbe
    14 years ago
    last modified: 9 years ago

    Best to start a new thread (see forum instructions) so that more people see/read/try to help...

  • clinchvalley
    12 years ago
    last modified: 9 years ago

    Interesting discussion with loads of helpful responses. My CV22 will turn over but won't fire. I thought it might be the backfire solenoid, but took it off and it works very well. Short of taking off the carb, is there anything else I should check? I recently did the spring tune up (fuel filter, oil and filter, spark plugs, air filter). I forgot to clean out the gas prior to winter storage.

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