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Murray lawn mower will not stay running

Posted by jasperfish NH (My Page) on
Tue, Aug 3, 10 at 12:16

I have a 2001 Murray select with a 16.5 hp I/C OHV Briggs and Stratton engine. I was mowing the lawn and the engine stalled. I let it set and it would start for about 3 sec and die. I replace the fuel line and pulled the bowl off the carb and fuel flows freely. I am lost any ideas?
Thanks for the help in advance


Follow-Up Postings:

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RE: Murray lawn mower will not stay running

if no spark right after it quits, pull engine shroud to clean out fins. If still no spark, try spraying some rattle can carb cleaner down carb throat with air cleaner removed. If engine tries to start, pull carb off and clean well including all passageways with small dia stiff wire. Blow out with compressed air.
If engine does not fire with rattle can start procedure, may be ignition coil going bad.


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RE: Murray lawn mower will not stay running

" I am lost any ideas?"

Before doing anything drastic, remove the valve cover and see if everything is in place and apparently working OK.

Walt Conner


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RE: Murray lawn mower will not stay running

Thanks for the insite I will give that a shot after work today.


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RE: Murray lawn mower will not stay running

Ok I have changed the ignition coil, new batery, and cleaned carb. It started and ran well and I am still having trouble with starting, I think it is a compression issue. I turn the key and it turns a bit and stops and will do this a few times and the start. I pulled the plug and the motor turns over with no problem but I put the plug back in and the problem persists, any ideas how to fix.


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RE: Murray lawn mower will not stay running

In your opening post, you say you have a "16.5 hp I/C OHV Briggs and Stratton".
Need to double check that because the I/C engines are all L-head design, not OHV. (as far as I have ever known)
Post the actual model and type numbers from the engine.
If this really is OHV, you may need a valve adjustment to mitigate the "compression issue".


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RE: Murray lawn mower will not stay running

"16.5 hp I/C OHV Briggs and Stratton".
Need to double check that because the I/C engines are all L-head design, not OHV. (as far as I have ever known)
Post the actual model and type numbers from the engine.
If this really is OHV,"

Yeah, can't really tell what you have. I had one guy argue with me last week that his 42 series was a V twin because it had two pistons.

Walt Conner


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RE: Murray lawn mower will not stay running

I will double check the OHV but that is what it says on the shroud. I thought it might be the valve. that scares me to adjust them. I will post the numbers on the engine tonight, thanks for the insight.
Eric


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RE: Murray lawn mower will not stay running

Ok, The valve are adjusted (really not that hard to do :) )It starts much easier but still sticks alittle. My last question is, I start the engine and there is drips of gas on the floor and gas on the muffler and it seems to be coming from the muffler what is going on ?
Thanks everyone for all the help you have all been a life saver


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RE: Murray lawn mower will not stay running

***"but still sticks a little"***
DO NOT operate the engine again until you have changed the oil and filter (if it has an oil filter).
The gas you see dripping out indicates that the needle valve in the carburetor is not shutting off the fuel when the machine is not running.
The "sticking" you refer to is caused by gasoline that has run into the cylinder creating a condition known as "hydrostatic lock up".
The gas that gets into the cylinder also gets into the engine lube oil, diluting the oil and doing great harm to the engine internal parts.
It is most important that you install an inline fuel shutoff valve in the gas hose between the fuel tank and the fuel filter, and you must turn the fuel valve off except when you are operating the engine. Every time you shut off the engine, turn off the fuel. Make it a habit. Put a reminder note on the dash if you have to.
There has probably been enough engines ruined because of gas contaminated oil to create a small mountain if they were all piled up in the same spot.

Years ago, all OPE engines had fuel cut off valves on the fuel tank, and you were told to shut off the fuel when the machine was not in use.

In the interest of saving literally pennies, the OEMs have discontinued the shut off valves as a standard feature.

Some will say you need to fix the carb so the needle does not leak. I don't disagree with them, but you still need to add and use an inline fuel shut off valve.
I disagree with folks who say "Just fix the needle, forget the cut off valve." There have been too many instances of needle valves leaking for you to trust them with the life of your engine.

Typically, an inline fuel cutoff valve can be bought at any OPE shop for under $10. Can you buy an engine and have it installed for that price?


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RE: Murray lawn mower will not stay running

Even if the Carb Metering Valve was Holding , MANUAL SHUTOFF VALVE is a must for SAFETY Alone !


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RE: Murray lawn mower will not stay running

Just to keep everybody on the same sheet of music, a carburetor "metering valve" is not the same as a float needle valve.
A metering valve is usually the movable or adjustable component part of an adjustable main jet type of carburetor.
Though these may be tapered or needle shaped, their job is much different than that of the float needle.

The float needle in your carb operates exactly like the float valve in a conventional bathroom toilet tank float valve system.
When the toilet tank (carb float bowl) empties, the float drops and allows the water valve (carb needle valve) to open letting water flow into the tank (carb needle lets gas into bowl).
When the tank fills up with water (carb bowl with gas), the float rises up with the increasing water level (carb float rises with gas level) and the float valve will completely shut off the incoming water (carb float needle will shut off the incoming fuel) when the preset level is attained.

The toilet tank empties when you flush the toilet.
A close analogy for a carb would be when you are running the engine with wide open throttle when the engine is under a load (or when you run the fuel tank completly "dry").

A leaking toilet tank valve will permit water to seep past it and overfill the water tank to the point that water will drain out of the tank through the vertical overflow stand pipe and into the toilet below (instead of overflowing the tank and flooding your house). The vertical stand pipe is a "safe guard" feature in your toilet configuration.

But, when the float needle of a carburetor leaks (or the float fails to rise for some reason), the carburetor bowl overflows and gasoline drains into the engine induction passage (intake manifold) and into the engine.


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RE: Murray lawn mower will not stay running

In Less than 4.5 Paragraphs , whether a more Precision form of Metering Valve or the less Complex and Precise Inlet Float Activated Needle Valve , THE FACT REMAINS A INLINE MANUAL SHUTOFF VALVE IS A MUST FOR SAFETY ALONE ! Inlet Valves Fail and so do Floats , have replaced numerous of each , but never have flooded a Engine or Crankcase , since I include a manual valve and utilize same .


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RE: Murray lawn mower will not stay running

Brevity is less important than accuracy of content.


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RE: Murray lawn mower will not stay running

Redundant Accuracy without Reason and avoiding the Point of the Conversation is Self Centred !


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RE: Murray lawn mower will not stay running

You cannot learn if you are not taught. Some learn with pictures, some with words. Painting a picture with words is the key. Mownie and ewalk both do it very well. That's the long and the short of it.


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RE: Murray lawn mower will not stay running

Popcorn: No Picasso here Bro lol ! My point was the Creative Editing is not req'd. You call it tomatoe I call it tomotoe . The Jest of my Post was to IDENTIFY SAFETY as PARAMOUNT IMPORTANCE to the Manual Shut off Valve Requirement from Mownies Original Advice. Not for Internal Engine Damage Protection due to compromised oil integrity from gas contamination . Although very important point for Engine Integrity , it is secondary to Fire Damage and Personal Injury or loss of life in a House Fire Situation. Did not wish to get in a debate over semantics . Mownie is correct there is a definite diference within Normal Fuel Inlet Needle Valve and more Precise Fuel Inlet Metering Valves . I have work on both types . Mostly Walbro WB & WG Series Carbs on Chainsaws Pioneer , Solo , Jonsered referred to as Metering Needle Valves . Also Keihein NG Tiltison HD Series within various Snowmobile's Snow-Jet & Arctic Cat & Polaris were again the Needle Valves are referred to Metering Needle Valves . Both examples are Atmospheric & Density (sensitive) controlled units . However the secondary examples within snowmobiles are 2-stage Inlet Needles with primary and secondary fuel circuits. Much more precise fuel delivery back in the 70's . Sorry probably a little too much info. Mownie is a Smart Dude just gets a little carried away with the Editor and Chief Title . Neither form of Fuel Inlet Control Valve Application would have Confused or Negated the Point that I was making "Safety" over Engine Maintenance. Anyhow I hope the OP gets his tractor running and installs the Manual Fuel Shutoff to protect his Investments as a Homeowner !


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RE: Murray lawn mower will not stay running

Right on ewalk. Wasn't getting on to anyone. Safety should always be first. Since I have started readings this forum I have completed a couple of upgrades on my mowers. One being to put a cutoff valve in the gas line. Ya'll just keep up the good work and I'll monitor in my detached-attached mode.(to steal a line from "The Hallelujah Trail" movie)


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RE: Murray lawn mower will not stay running

Popcorn: I know Bro. No Harm...No Foul. All The Best :)


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RE: Murray lawn mower will not stay running

i have a 12 hp industreal motor and it crancks but wont stay running i changed spark gas and cleand carb some one help me out


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RE: Murray lawn mower will not stay running

hey guys im have almost the same problem. I cleaned the carb, plug, gas filter n new gas. I put it all back together n she still wont run. so I took the top cover off n put my hand over the part that sux air then it starts but wont stay running if I pull my hand away. so I tried putting the cover back on n the air filter and still nothing . seems like that only way it starts is if my hands over it .... NE ideas guys could really use sum input please THANX Maurice


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RE: Murray lawn mower will not stay running

That part that sux air is the carburetor. And it needs to be taken apart and cleaned out.
But that is not a job that you can do.
Take it to a small engine shop.


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RE: Murray lawn mower will not stay running

no that's not it because I did that I took it apart and cleaned it all out nice n clean n put it all back together the right way I can handle it . its almost like the choke doesn't work or something. so I block the air and get it to start but then it revs high and low then dies wont stay running.


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RE: Murray lawn mower will not stay running

So, does it have a choke? Can you see the choke plate opening and closing?
Is this a machine you have owned for a while, or is it something you only acquired recently? Or in other words, do you know the history on this machine?
Whether you have a working choke plate, or whether you are limiting the air by smothering it with your hand, the fact remains that it will not run when the air is not being limited...........and that means IT IS NOT GETTING ENOUGH FUEL. Carburetor problem.
Your ball.


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