Stuck Intake Valves

[Dave_N_Ga]

I took the 51 out yesterday, changed the oil and lubed it. Put about an hour on it and then let it sit. When I tried to re-start it last night it spun like it had no compression. That"s because it doesn"t, ALL 4 intake valves are stuck open. The gas does smell a bit sour but the tractor ran great. Is it possible the bad fuel caused this? I can"t see how the oil I used would have only caused the intakes to stick. I"m pulling the intake now and will soak the stems with PB Blaster, ATF, or solvent if I need to. I"m going to drain and flush the tank. Not sure if I should change the oil again. Anyone ever seen this before?

Thanks!

 

[Dave_N_Ga]

I would like to add that if I turn the engine over, the valves stick open. After 10 - 15 minutes they will close on their own only to stick open again when the engine is turned over.
Something definitely gummed them up.

 

[old]

Cap off the Carb air intake and then fill trhe engine with ATF and let it sit a day or so. Be sure to spin the engine over first so the valves stick open that way the ATF gets to the valve stems where the cleaning is needed

 

[John Smith8N]

Definitely from stale gas. Happens to a lot of people every spring. Get that stuff flushed out of there and it will be fine.

 

[Hobo,NC]

(reply to post at 18:42:47 04/02/13)

I have a valve issue with a 52 8N I rebuilt some 50hr. ago,,, the last few years I may run it less than a hour a year... It has became a beach to start and the fuel does sour but I battle threw it till the last time I ran it,,, I know a valve is stuck open now and want shut I did give it a ATF treatment but a no go... I plan to R&R the manifold and side covers for a look see... It has a 9N head on it (all I had at the time the original was cracked) now have a good 8N head so plan to just dig in and make the swap at the same time,,, The 9N head killed the power so look'n to get my HP back...

 

[Dave_N_Ga]

So what i did .......... was apply some heat to the side of the block and the valves began to move enough to fire it off and it quickly hit on all four. With 4 gallons of NEW fuel and a quart of ATF added to it I cut the front three acres. The tractor sat all night and fired right up this morning.

Thanks to all for you help, I never imagined old fuel could have caused so much grief.

 

[Bob Harvey]

Glad you got the 'ATF' clue somewhere. I should have suggested it before, my bad. Keep adding a 1/2 cup or so at every fuel fill ---couldn't hoit ! Back in the 'day' I ran a VW repair shop and told all my customers (hippies and the like) to do the same thing. Helps lubricate and cool the valves on an air cooled engine. HTH

 

[souNdguy]

good ole atf.

add some to your gass and a lil to the oil from now on.

i'm not a fan of mechanic in a can.. but atf comes close..