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Discussion Starter · #1 ·
hi
i have a 12hp briggs l head engine
recently got her started but wont idle and after running for a while, when i stop it, smoke rises from the exhaust or valve side of the engine
just before i release the starter and let it run, it lets off a pop/backfire and just as i release the power from full it dies and also pops.
i can see a flame coming from the exhaust.
im not sure if the valves are a problem or if its carb issues
the exhaust valve was initially stuck open when i got the engine and i managed to get it free without removing it as i couldnt manage to release the retainer on the side of the engine
any help would be apreciated
thanks :help:
 

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It is always a good idea to rule out the carb, but since you said the exhaust valve was initially stuck when you got it, that does raise an eye brow. After you freed the valve and got it running, did it always run this way or is it a new issue that arised?

If it's not carb related, it may be that it needs a valve adjustment.
 

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Discussion Starter · #3 ·
thanks for the quick reply
it was like this since the first time i started it
i tried releasing the exhaust valve's spring with no luck so could not properly clean the stem
but it did seem to return to the closed position
is there a technique on removing the spring keepers without the special tool?
the exhaust valve does not lie flush like the intake valve, is this ok? the rods to touch tho in the spring 'box'
thanks again
 

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It sounds like the valve is still not seating properly. It shouldn't stick up any more than the intake. There are a couple different kinds of valve spring keepers. If you take a pic of what you've got, maybe we can help you to figure the problem out.
 

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Wondering if your seeing the Compression release on the Ex valve...that may lead you to suspect it is not seating...I would think your carb is OK...But I would remove the flywheel nut and look very closely at the key, it may be partially sheered..retarding the spark...causing sparks and flames at exhaust. and intense heat...
 

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Discussion Starter · #6 ·
Thanks for all the replies
It's a brand new key
Will try send pictures when can.
If it's the compression release valve keeping the valve up a bit, then how do you check the gap with a feeler gauge?
 

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Discussion Starter · #8 ·
Hi again
Engine starts and runs quite well
Thanks for the help
Ran into another problem tho,
When revving the engine, it smokes quite a lot of blue smoke.
It's also dripping alot of oil from the cowl under the cylinder.
When I took the cowls off, it appears that the oil may either be coming from the exhaust outlet or the cylinder head.
I have also seen a bit of oil in the carb as it has no filter on at the moment due to testing.
Has anyone got any ideas?
How will I know if the rings are a problem or if it's something else?
Thanks
 
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