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Discussion Starter #1
Old L model 7.6 won't start.Been running fine for many years.Fouls a plug out ever no and than.I clean the plug and go on.The other day I had mowed for 45 min or so,shut her down to take a break.Haven't been able to re start since.Always started on 2-3 pull for many a year,even after setting all winter.I have noticed flooding after several cranks.Possible stuck float?Thanks
 

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Do you feel a compression stroke just before the mag snaps? I sometimes have a problem with an exhaust valve stuck open. Open valve = no compresson = no start. I have to remember to rotate the engine to a compression stroke as soon as I turn it off so that the exhaust valve is down for the next start.
 

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Per PaulL, check for compression.

If you don't have compression, it's likely a stuck valve. Cheap fix: Put several spoons of Marvel Mystery Oil in there and let it sit for a few hours or a day. That will often free a stuck valve enough to run. If that works, run a little MMO in the fuel, to prevent a reoccurance.

If it's been fouling plugs, that might mean too rich. Not necessarily a stuck float. You can tell if the float is stuck or the needle is leaking by removing the air inlet tube at the carb. If fuel drips out steadily, you need to rebuild the carb.

It could also just be way too rich. If you get the valve unstuck, reset the carb mixture controls per the manual.
 

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Discussion Starter #5
Do you feel a compression stroke just before the mag snaps? I sometimes have a problem with an exhaust valve stuck open. Open valve = no compresson = no start. I have to remember to rotate the engine to a compression stroke as soon as I turn it off so that the exhaust valve is down for the next start.
got good compression,thanks
 

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Discussion Starter #6
Per PaulL, check for compression.

If you don't have compression, it's likely a stuck valve. Cheap fix: Put several spoons of Marvel Mystery Oil in there and let it sit for a few hours or a day. That will often free a stuck valve enough to run. If that works, run a little MMO in the fuel, to prevent a reoccurance.

If it's been fouling plugs, that might mean too rich. Not necessarily a stuck float. You can tell if the float is stuck or the needle is leaking by removing the air inlet tube at the carb. If fuel drips out steadily, you need to rebuild the carb.

It could also just be way too rich. If you get the valve unstuck, reset the carb mixture controls per the manual.
Don't have a stuck valve.Fuel did drip out of intake tube.I will try and adjust carb. and lean it down some.Thanks
 

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Discussion Starter #7
Per PaulL, check for compression.

If you don't have compression, it's likely a stuck valve. Cheap fix: Put several spoons of Marvel Mystery Oil in there and let it sit for a few hours or a day. That will often free a stuck valve enough to run. If that works, run a little MMO in the fuel, to prevent a reoccurance.

If it's been fouling plugs, that might mean too rich. Not necessarily a stuck float. You can tell if the float is stuck or the needle is leaking by removing the air inlet tube at the carb. If fuel drips out steadily, you need to rebuild the carb.

It could also just be way too rich. If you get the valve unstuck, reset the carb mixture controls per the manual.
Might be way too rich.I'II try to adust carb.Thanks
 

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Discussion Starter #8
What is the spark plug gap suppose to be.One manual says .025 another says .032?
 

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It's not that critical. Anywhere around .030 is fine.

I've seen these things run with plugs that have been dropped and have practically no gap. I've also seen them run with the plug wire having separated from the plug, with the mag throwing a spark across a 1/2" air gap.

It's not not that critical.
 

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If you have the rubber intake hose that curls around for the carb, make sure you take that off and check for fuel laying up in there. Try cranking it with the hose off. My carb leaks a little bit, and if it let it sit too long with the valve under the tank open, it will dribble fuel into the bottom of that hose. Then when you go to crank it, it sucks all that fuel laying in the bottom of the hose up in the engine and drowns the sparkplug. It will finally start if you crank it long enough or take the sparkplug out and dry it off.

I always shut my fuel tank valve off when I let it sit. Mine has always done this, must be the fuel valve in the carb leaking just a little bit.
 

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Discussion Starter #11
Do you feel a compression stroke just before the mag snaps? I sometimes have a problem with an exhaust valve stuck open. Open valve = no compresson = no start. I have to remember to rotate the engine to a compression stroke as soon as I turn it off so that the exhaust valve is down for the next start.
Plenty of Compression
 

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Discussion Starter #12
Per PaulL, check for compression.

If you don't have compression, it's likely a stuck valve. Cheap fix: Put several spoons of Marvel Mystery Oil in there and let it sit for a few hours or a day. That will often free a stuck valve enough to run. If that works, run a little MMO in the fuel, to prevent a reoccurance.

If it's been fouling plugs, that might mean too rich. Not necessarily a stuck float. You can tell if the float is stuck or the needle is leaking by removing the air inlet tube at the carb. If fuel drips out steadily, you need to rebuild the carb.

It could also just be way too rich. If you get the valve unstuck, reset the carb mixture controls per the manual.
Plenty of Compression.
 

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Discussion Starter #13
Per PaulL, check for compression.

If you don't have compression, it's likely a stuck valve. Cheap fix: Put several spoons of Marvel Mystery Oil in there and let it sit for a few hours or a day. That will often free a stuck valve enough to run. If that works, run a little MMO in the fuel, to prevent a reoccurance.

If it's been fouling plugs, that might mean too rich. Not necessarily a stuck float. You can tell if the float is stuck or the needle is leaking by removing the air inlet tube at the carb. If fuel drips out steadily, you need to rebuild the carb.

It could also just be way too rich. If you get the valve unstuck, reset the carb mixture controls per the manual.
The needle was out over three turns +.Adjusted it to two and half,still flooding after a few pulls.Fuel doesn't drip all the time,just when you give it a few pulls.Never hits or trys to start.
 

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What evsnova said

If the carb is dubious, shut off the fuel valve. Pull the plug. Make sure you're getting a spark at TDC. Make sure the plug is relatively dry and clean. Put it back, and hook up the wire. Give it half a shot of starting fluid or carb cleaner. Crank it over.

If you've got spark and compression, that should give you at least a couple of puffs. If it does, give it a bigger shot. You can generally get it to run 4-6 hits just on starting fluid, even when the fuel is off.

If that all works, turn the fuel on, and crank it immediately. Even if something in the carb is leaking, that should get you some more puffs, and maybe start running for real.
 

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Yes like jrd said make sure it's sparking at the right time. Not sure why the timing would just change for no reason but it's really easy to verify. Either stick a dial indicator, or failing that a dowel rod or anything that fits in the spark plug hole and turn the engine over very slowly on the compression stroke, watching the object rise. The impulse snap in the magneto should occur right at TDC or just ever so slightly after TDC, before it even starts moving downward. Side note, make sure the mag is grounded out any time it snaps, by either holding the kill button in or sticking a screwdriver or something between the kill button on the mag and the body. It's not good for the coil to spark with no ground.

Btw you can also pour a small amount of gasoline in the spark plug hole if you don't have carb spray or starting fluid.
 

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Discussion Starter #18
Sorry for the delayed up date Fellows.Waited for a little cool down and dealing with a spouse with dementia.The starting fluid did the trick on starting it.Once started runs great,doesn't miss a lick.But once stopped it does drip fuel from the carb.Got to get a new fuel shut off valve.Thanks
 
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