Engine Question


Old 04-28-03, 06:56 PM
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6.5 craftsman no compression

Once again I look to the experts for help. The initial problem with my 6.5 hp craftsman lawnmover was a sheared flywheel key. Before I replaced the key, I wanted to check the compression so I screwed in a tester and pulled. It was too deep into the head and the first pull produced a 'clank'. Now after I've replaced the key......no compression. I hear a 'whistle' from the breather tube, the crank seems to turn fine but there is a funny 'rachet sounding' noise from the bowels of my 2 yearold lawnmover.


Also the model is 143.996518.
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Old 04-28-03, 09:09 PM
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Your engine is a flat head engine so the spark plug is over the valves more the the piston. The ratcheting noise is some thing rubbing on the crankshaft gear which is most likely the broken camshaft. You most likely bent a valve and broke the camshaft. If you hear the compression coming from the air filter, the intake valve is the bent valve. You won't be able to tell how much damage was done until someone opens it up.
The camshaft is a little over $40.00.
Old 04-28-03, 10:32 PM
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Hello Schmitty!

Sounds like you may have trouble. Pull the head off and rotate the engine. See if you have a valve that is sticking or not moving. I think, like Roger, that you have valve problems.
Old 04-29-03, 04:12 AM
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Compression Test ??

In all my years of doing this, have NEVER heard of a tester
that screwed in THAT FAR ?? Have never seen a tester with
that kind of reach on it either ?? WOW !! He may also have
knocked a hole in the top of the piston vs. broken or damaged
the camshaft ?? As Cheese and others say, you won't know
UNTIL you tear her down to see....Best of Luck when you do.

Old 04-29-03, 08:01 AM
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Most of the small engine testers I have seen have adapters for the various spark plug holes...what brand of tester is this????
Old 04-29-03, 11:13 AM
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Again I make it into the book of re-writes. I used an automotive tester...bad idea!

I tear it down an hope for a bent valve.....could the retainer clip have popped off the end of the valve?
Old 04-29-03, 06:26 PM
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It could have, but probably not. If it did, then the valve is probably broken off at the stem.
Old 05-01-03, 07:59 AM
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Could also be something in the cam drive broke (ratcheting noise when you turn the crank) when what ever happened to shear the flywheel pin. Thus the cam isn't even turning.

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