Frozen exhaust valve

[JohnnyTillotson]

This oldie I picked up a few weeks ago has a frozen exhaust valve. I can tap it back down during the intake stroke and it comes back up during the exhaust stroke but it sticks up. I shot PB down into it. Hopefully that frees it up but any other advice?

 

[capguncowboy]

Did you pull the oil breather cover (just below the valves on the side of the block)? My guess is the spring or retainer has come loose. Might want to replace them

 

[JohnnyTillotson]

Did you pull the oil breather cover (just below the valves on the side of the block)? My guess is the spring or retainer has come loose. Might want to replace them

Not yet. I just started messing with it right before Johnny's bed time. I will tonight. Pics to follow! Thanks.

 

[JohnnyTillotson]

Did you pull the oil breather cover (just below the valves on the side of the block)? My guess is the spring or retainer has come loose. Might want to replace them

Oh, also if you notice in the pic of the head I broke two bolts taking the head off on that side close to the exhaust valve. I thought that more than a coincidence. Might there have been catastrophic failure of this valve during operation. Like it overheated

 

[jeep2003]

You should just pull the valves out and clean everything up. Thats pretty nasty looking

 

[JohnnyTillotson]

You should just pull the valves out and clean everything up. Thats pretty nasty looking

Yeah, heh heh.. I hear ya.

 

[JohnnyTillotson]

Yeah its stuck... haha. The lifter goes up n down just fine. So guess this just needs a good cleaning. The exhaust valve being open would be the cause of no coppression right?

 

[jeep2003]

yup it cant compress air if its free to flow out the exhaust

 

[capguncowboy]

Yes. That's really clean compared to the oil breather housing on the HS40 that i just rebuilt. I'm surprised is gummed up

 

[mc73cromags]

Pull the valve out clean it and check that its straight. Its possiible it is stuck from sitting. Years ago A friend put a long reach spark plug in his mini and tried to start it...when he pulled it the valve opened and hit the plug. The valve bent and was stuck open. maybe the guy that had it before you did something similar? Good luck with it, looks like a cool little engine.

 

[jeep2003]

Thats really intresting. Years ago my brother discovered a bent valve in one of our engines that explains why. It was always a mystery how you could bend a valve in a flathead lol

 

[JohnnyTillotson]

Pull the valve out clean it and check that its straight. Its possiible it is stuck from sitting. Years ago A friend put a long reach spark plug in his mini and tried to start it...when he pulled it the valve opened and hit the plug. The valve bent and was stuck open. maybe the guy that had it before you did something similar? Good luck with it, looks like a cool little engine.

I think it's carbon build up and from sitting. In the beginning I could tap it down with 5 or 6 sharp taps of a wooden screw driver handle during the intake stroke. After a few days of shooting PB Blaster in there it'll go down with one tap. Meets the lifter perfectly. I'll eventually take it out and clean it up. Thanks.

 

[oldfatguy]

I had a 3hp briggs with the same problem. It will eventually free up and start moving but it is best to take the valves out and clean them before they wear out and damage the valve guides in the block. The problem with my engine was caused by over heating due to clogged up cooling fins. It sounds like that's what happened to your engine too. It turned out that the exhaust valve was burned and also needed to be replaced so that is something to look for when you take the valves out. Then clean those cooling fins. It's important to run all the side tins in place because they direct air around the valves to cool them.

 

[JohnnyTillotson]

I had a 3hp briggs with the same problem. It will eventually free up and start moving but it is best to take the valves out and clean them before they wear out and damage the valve guides in the block. The problem with my engine was caused by over heating due to clogged up cooling fins. It sounds like that's what happened to your engine too. It turned out that the exhaust valve was burned and also needed to be replaced so that is something to look for when you take the valves out. Then clean those cooling fins. It's important to run all the side tins in place because they direct air around the valves to cool them.

I took the exhaust valve out and it looks ok but the guide is crammed with carbon and gue from shooting PB Blaster down there. Ill clean it all up and see how it goes.

 

[lostinbaja]

I work for an automotive restoration shop and I can't tell you how many cars we in the shop that have all the valves stuck in the guides due old varnished fuel. I completely rebuilt a 216ci six cylinder Chevy engine for a customer's 52 Chevy, he flushed the fuel system but left a layer of varnish in the tank. He installed the engine and proceeded to put 8,000 miles on it during the summer, in October when the outdoor temperature dropped, the engine would not start. He had the car towed to the shop, where I determined all the valves were stuck in the valve guides. I had to pull the head and put it in an oven to get the valves out. It was all due to the residual varnish left in the fuel tank.
Just a little FYI.

Jerry...