Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Engine Question


SCHMITTY's Avatar
Visiting Guest

Posts: n/a

04-28-03, 06:56 PM   #1  
SCHMITTY
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.


Thanks
Schmitty

Also the model is 143.996518.

 
Sponsored Links
rogerh's Avatar
Member

Join Date: Nov 2002
Posts: 233

04-28-03, 09:09 PM   #2  
Schmitty:

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.

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,570
GA

04-28-03, 10:32 PM   #3  
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.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
Tcumcman's Avatar
Visiting Guest

Posts: n/a

04-29-03, 04:12 AM   #4  
Tcumcman
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.

Tcumcman

 
Joe_F's Avatar
Visiting Guest

Posts: n/a

04-29-03, 08:01 AM   #5  
Joe_F
Most of the small engine testers I have seen have adapters for the various spark plug holes...what brand of tester is this????

 
SCHMITTY's Avatar
Visiting Guest

Posts: n/a

04-29-03, 11:13 AM   #6  
SCHMITTY
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?

 
cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,570
GA

04-29-03, 06:26 PM   #7  
It could have, but probably not. If it did, then the valve is probably broken off at the stem.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
truckdrivinfool's Avatar
Visiting Guest

Posts: n/a

05-01-03, 07:59 AM   #8  
truckdrivinfool
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.

 
Search this Thread