641 Help

[Old 49]

My 641 will not quit skipping. I put on new head gasket,lapped the valves,adjusted the valves cold&hot still can"t get it to quit. It still has strong power and it will pull just skipping.
New plugs,wires,points,rotor condenser,rebuilt carb,checked timming with light. Any help would great I"m running out of ideas. Thanks

 

[Anonymous-0]

Define skiping, you mean missing? did you check the electrodes inside and out on the cap?

 

[old]

How old is the cap and rotor. Caps and rotors need to be replace about every other time the points are done. Also when was the last time you cleaned the air cleaner and changed the oil in it??

 

[Old 49]

The cap and rotor looks good I will replace them good idea.When I say skipping it sounds like putt putt putt out the back.What about a weak valve spring?It sound just like a burn valve sounds. Thanks

 

[Matt L]

Is the distributor shaft loose?

 

[Anonymous-0]

A weak valve spring? check the compression. Point gap and dwell correct? If it's that noticable you should be able to pull plug wires one at a time and determine cylinder.

 

[Old 49]

I went out after church today and pulled the valve cover off to check my gap and the rocker arm and about half of the inside had water in it.
So I started it up and where the carb bolts on where is water dripping while it is running.Time for a new head? Or what could it be? Thanks

 

[Anonymous-0]

Could be cracked head or blowed head gasket. Head gasket should show up on plugs. It will make a mess, but if you warm the tractor up and pull the cover and restart at idle {while warm} you may be able to tell if it's a cracked head. Is crankcase oil milky? Is the water comeing from carb or behind it? If you pull head try not to mess up old gasket and it will have tell tell marks if its blowed or seaping.I don't know what it cost any more,but might not hurt to have the head magnafluxed before you spend the money for another one.

 

[Old 49]

I could"nt see a crack in the head.But the #3 plug was wet.I"m ging to do a compresson test after work Monday.I just put the head back together Sat.New gaskets on the whole top end.
When I took the head off the gasket was blown but the head bolts were not up to torque so I thought that was my problem.I"ll be in touch with the test results. Thanks

 

[john_Bud]

(quoted from post at 18:04:30 08/08/10) I could"nt see a crack in the head.But the #3 plug was wet.I"m ging to do a compresson test after work Monday.I just put the head back together Sat.New gaskets on the whole top end.
When I took the head off the gasket was blown but the head bolts were not up to torque so I thought that was my problem.I"ll be in touch with the test results. Thanks

Loose head bolts will blow out a head gasket pretty quick. I hope that's your issue. Use a quality gasket.

Before slapping on the new one, have you checked that the block is flat? Here's a link with info on it.

http://www.aa1car.com/library/ic697.htm

 

[Old 49]

Finally got it running good compression check was 150 across the head It turned out to be a bad switch.Someone tried to wire it up and I still can"t figure it out so took everythig loose and started over and after rewired and a new switch it"s purring like a kitten Thanks to everyone,I"ll be back.