Tecumseh 12 Hp.

[Jazz]

This is engine from my Avatar
I’m convinced compression release mechanism is not functioning. Trying to remove this crankshaft cover. Does not seem to want to leave the mother ship. Any suggestions, all bolts removed. Am I missing something? TIA

 

[dodge trucker]

I don't remember if it was that series engine or some other but I remember reading somewhere +a long time ago)l that there's an engine out there where you gotta pop the seal and turn a couple of tabs that retain the bearing.
I think that the bearing on those stays with the crank.
I do have a factory service manual at home for those cast iron tecumseh engines. But I'm still at work right now.

 

[MFDAC]

I'm not sure what may be hanging it up, Jazz? If that is a HH120, the crank cover came off pretty easily on my 1975 MF12G while still in the frame. Had to re-power the tractor though. The only mechanism I saw in there was the governor. I do remember from 20+ years ago, go kart racing, some engines had a compression release ground in the cam lobes. This engine may have been that way too?

DAC

 

[Jazz]

I'm not sure what may be hanging it up, Jazz? If that is a HH120, the crank cover came off pretty easily on my 1975 MF12G while still in the frame. Had to re-power the tractor though. The only mechanism I saw in there was the governor. I do remember from 20+ years ago, go kart racing, some engines had a compression release ground in the cam lobes. This engine may have been that way too?

DAC

View attachment 32921

Compression release mechanism may be the small gear in the pic. According to manual all HH120 had a CRM

 

[esbbent]

This is engine from my Avatar
I’m convinced compression release mechanism is not functioning. Trying to remove this crankshaft cover. Does not seem to want to leave the mother ship. Any suggestions, all bolts removed. Am I missing something? TIAView attachment 32883

Jazz, looking at your picture and MFDAC's picture it looks like the one bolt on the top just right of the crankshaft needs to come out. The one with the metal piece on it with a hole in the end. I counted 9 bolts that hold the cover on, the 2 guide pins will make it a difficult to move for the 1st 1" or so coming off.

 

[Jazz]

Jazz, looking at your picture and MFDAC's picture it looks like the one bolt on the top just right of the crankshaft needs to come out. The one with the metal piece on it with a hole in the end. I counted 9 bolts that hold the cover on, the 2 guide pins will make it a difficult to move for the 1st 1" or so coming off.

Correct. Cover came off easily. Seems the CRM is working. The spring is intact so valves must need adjusted. The engine is hard starting and it’s not the starter.

 

[Jazz]

Hmmm. Is that notched gear on crank gear a timing mark? Just noticed it. Intake is 010, exhaust is 022, should be 020

 

[Jazz]

Time out!

 

[Jazz]

It appears something got bounced around the way head and top of piston have some chipping

 

[Jazz]

But. This engine purrs when running but won’t start unless I’m boosting with truck, even my deep cycle battery barely spins engine over and not fast enough to start engine

 

[TAHOE]

Hmmm. Is that notched gear on crank gear a timing mark? Just noticed it. Intake is 010, exhaust is 020, should be 020 View attachment 32929

Yes the notched tooth is the timing mark.

Make sure you have the right gasket for the cover, it is used as a shim to give proper end play for the crank.

 

[dh1]

With the head off and rotating the engine by hand you should see the exhsust valve open/move a tiny amount.
If it doesn't the valve clearance is too much.
IMO