If you remove the spark plugs and turn the flywheel by hand you should be able to tell if something if binding. I have not checked this engine but typical end play is a min. of .002" that is about the minimum amount you can feel. I hit the crankshaft on each end with a hammer with a pc. of wood between then grasp the end of the crankshaft and pull back and forth. You can of course use a dial indicator which I have but never use for that.

I would say you made a mistake by leaving out the gasket. In most cases the gasket thickness is important. They are offered in different thickness with .009" being an average.

Walt Conner

Thanks for the follow-up Walt. It's spitting gas from the carb, so I'm going to see if I can solve that problem first and then I guess I will be pulling her again. It's been a lot of work, but it's been a great learning/bonding experience for me and my 16 year old and I think we may have found a new hobby together.
Now if we could just get the grass cut....

Cedarghost,

When you pick up the new sump gasket grab a copy of Briggs repair manual. It should be about $20 and will address the crank end play measurement and gov adjustment proceedures.

Good luck, Alan

Thanks Alan. I got the manual and ordered the gasket. Went ahead and ordered rings, valve seals, valves, valve gaskets, valve cover gaskets, valve springs and a flywheel key too while I was at it. After mowing season, me and my boy will break it down and replace the valves and rings. We may even tackle rebuilding the carb. I have no experience with small engines before this, but I have rebuilt a few quadrajets. :)
First things first, I am itching to get home today and tackle my fuel problem. I am pretty sure the valve under the float isn't seated correctly, though the pulse hose needs replaced as well (saw a hole in it this morning), but I would think that would make it run lean instead of flood.

"First things first, I am itching to get home today and tackle my fuel problem. I am pretty sure the valve under the float isn't seated correctly"

After replacing the carb float needle I suggest you install an inline gas shut off valve and use it.

Great to hear your son is interested and you are working together. I doubt you need to replace all that you ordered but - - - - -

Walt Conner

Walt: And then ya have the problem of the guy who thinks that his buddy is playing tricks on him, by adding oil to his engine on his tractor, while he's asleep, or away from the house! It keeps making oil, even after he has drained some out, because it shows high on the stick!
Until----Bango---from lack of oil!
Thats why i always try to impress on the minds of the newbies the necessity of "double sticking" the oil level, "Pull it, wipe it, put it back in all the way--pull it again and read the results!"
Rusty Jones
Folks knew that, way back in the days when most folks knew something about automobiles, besides knowing where the key went to start the engine!

I think I solved me problem! Guess what it was.....
the transistor module had a bad solder joint...
my interittent firing came back and I realized THAT was the only consistent problem I had.
so I tore the ignition system apart. Pulled the flywheel, tested the coils, checked the diodes in the wiring harness. All good. The ONLY thing left tocheck was this little inconspiquos box mounted to the heat shield. So I took it off and when 8 was taking it apart sand and a little piece of ceramic fell out! Inside is what I believe is a Darlington Pair setup as a switch for the currentto the coils. Anyone have aschematic for it? A replacement i $70. I can get the components from work, but I don't know if I can get the old ones out to see what size they are.
now I obviously have'nt tested that this is the solution but I would bet on it big time. Ill let you know once I can build a new circuit or buy one. Anyone have a used one they want to sell?

"The ONLY thing left tocheck was this little inconspiquos box mounted to the heat shield."

According to your engine part number: 445777-0168-e1......
That 'box' is a voltage regulator. The alternator (mounted under the flywheel) produces an ac voltage. The regulator simply converts it to a regulated DC voltage that is used to charge the battery and run options such as headlights and electric PTO.

I could be wrong, but I don't think that a defectove voltage regulator would cause your problem with lack of RPM....

One way to eliminate the voltage regulator as a cause of your problem is simply to disconnect it (both of the connectors). If your battery is good the engine will start and run just fine (or more likely, with the same RPM problem as before) without the voltage regulator...

BTW...I posted pictures of the correct governor spring positions on your other thread....

Thanks a bunch for the pictures! Doesn't the voltage regulator on the Magnetron systems act as a switch for the current going to the plugs by turning it on and off? So if I remove the leads, there will be no current going to the coils. One plug has 2 wires and goes to the coils and the other wire goes to the alternator (Magnatron) ring. I'm assuming the current created by the magnets is going into this box where they are soldered to a darlington pair of transistors that are acting as a rectifier and switch. In other words, reducing the current to 16W (which is what the rating going to the coils should be), and then sending that out to the coils...in pulses. Or am I wrong? Will the plugs just run on the current coming from the coils created by the magnet passing? I wish I could find a schematic for all this.
The plugs are firing intermittently. While I haven't put a meter to the coils to see if the current is steady, I know the output from them isn't steady or the plugs wouldn't fire inconsistently.
Also, the lack of rpm could be caused if the plugs never fire consistently enough to create consistent combustion and that would also explain the flooding as well. If the plugs can't spark, the gas can't explode.
What am I missing?

Nevermind. I see what you mean. Dang. Where does the single wire that goes to the coils get it's current from?

Briggs Magnetron ignition DOES NOT use any external power (12V DC or otherwise) to perform it's task.
It is simply the passing magnetic field of the ignition magnet in the flywheel that produces 100% of the energy necessary to create a spark.
Accidentally introducing 12V DC to the Magnetron "kill wire" will kill the Magnetron.
The Magnetron ignition system is completely separated from the charging and lighting system (alternator).
So don't even think in terms like "current going to the coils". At no time is there ever current going to the coils.
The ignition kill wire connecting to the coils (Briggs term = "armatures") contains a pair of diodes.
The purpose of the diodes is to electrically isolate each coil from the other so they will not disrupt each other as they do their task. The diodes permit a single kill wire to connect to the tractor chassis wiring harness in order for all kill switches to be configured as Single Pole Single Throw. Briggs could have opted not to use diodes to separate the coils, but in order for that to work correctly.........all the kill switches would have to be Double Pole Single Throw type so as to keep the coils independent but still kill both coils when engine shut down is needed.
Briggs Magnetron ignition stops making sparks when the coil kill wire circuit is connected to the chassis/engine ground.

Got it. Thanks. It seems to be firing good. I have consistent spark (right now anyway). It starts fairly quickly, just wont rev to max rpm. The RPM will lower a bit when you move the throttle to slow. But when you move it to high, it doesn't rev as high as it should and any load will kill it.
I'm glad you mentioned the kill circuit, because something new is happening now. When I take my foot off the clutch, it dies. It never did that before and I know there is a safety switch for it somewhere, so I guess I will look for that. So assuming all kill switches run to the coils (makes perfect sense now) what is physically happening when I release the clutch is that the coil kill wires are grounded.
Awesome. I understand that. Now to figure out why the clutch is killing it all of the sudden, and why I don't have any high-end rpms...
I did try to adjust the low and high rpms by following the manual and bending the tangs and adjusting the throttle restrictor. I was able to get it to idle without dying, however, neither way that I bent the tang for the high rpm setting made any difference.
I did pull the flywheel and checked for a sheared key. The key was solid. I did a compression test and got 150 on one side and 147 on the other.
Am I correct in thinking the voltage regulator simply charges the battery (with the dc output) and runs the headlights with the AC output, so that the lights never run off the battery? And it doesn't need to be installed for the kill switches to work, right? Those are simply switches that ground the wires under the coils?

Thread closed and moved to 25 hp Briggs won't rev to top rpm. Thanks for all the help. Oh, Walt, you were right. The RTV was a bad idea...I went ahead and pulled and disassembled the motor and the RTV was pretty much mostly in the bottom of the crankcase....THANKS

I have used "Indian Head Shellac", to hold the sump gaskets in place while assembling the parts.
Also, always give the parts man the engine numbers, because the engines use different thicknesses of gaskets for different models. Even if they look the same--they aren't.
Also, when reinstalling the sump-if the bearing for the timing gear is a bit loose, and the gear won't stay in mesh with the crankshaft gear, i use a piece of thin cardboard shaped like a long-tailed check-mark, to hold in position as i lower the sump pan down onto the block. It wont hurt anything, and will soon disintegrate.

Rusty, I remember the Indian Head Shellac. My dad used to swear by it! lol
Man that brings back some great memories.
I closed this thread and several others and combined them into a thread entitled "25 hp Briggs won't rev to top rpms"
I'll post my solution when we find one, but I have a sneaking suspicion I let the cam turn a tooth or two when I put it back in last time. I definitely DID NOT check the timing marks....