#2 Exhaust Valve Sticking

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LeoM
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Location: Central Florida

#2 Exhaust Valve Sticking

Postby LeoM » Sun Apr 09, 2017 6:18 pm

My 1952 Cub was difficult to start and finally quit all together. This the tractor that everyone helped me with at the Deep South Cub Fest 2 years ago. It had sticky valves then and we found the head was cracked. I have a replacement head so I removed the cracked 1 and found #1 and #2 exhaust valves stuck open. #1 freed up with a little Kroil and a lot of cranking. #2 was stuck pretty tight so I tapped it with a brass tack hammer and it closed. I cranked the engine over and it stuck again. I soaked it over night which didn"t improve it. I rotated the valve a few degrees and it freed up. Rotated it back and it stuck again. It is acting like the valve stem is bent. I just ordered a spring compressor so I can't remove it yet. The valve spring seems to be in tact but I won't know for a few days.
I would appreciate suggestions or comments from anyone with experience with the valve train.
Thanks
Leo

Bob McCarty
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Re: #2 Exhaust Valve Sticking

Postby Bob McCarty » Sun Apr 09, 2017 6:24 pm

Leo, You may have to move it up and down a dozen or more times to free it up. Keep lubricating it and tapping it down, it will probably loosen without removal.

Bob
"We don't need to think more,
we need to think differently."
-Albert Einstein

LeoM
Cub Star
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Posts: 112
Joined: Sun Dec 07, 2014 7:02 pm
Zip Code: 32713
Tractors Owned: FARMALL FORUM
1966 Cub w/ IH 1000 Loader
1958 LoBoy w/ Wagner 45 Loader
1952 Cub w/ Woods 48" Bush Hog
1948 Super A w/ Finish Mower
1944 A w/ 3 Point Hitch
Circle of Safety: Y
Location: Central Florida

Re: #2 Exhaust Valve Sticking

Postby LeoM » Sun Apr 09, 2017 6:27 pm

It is free, but only at 1 location. If you rotate the valve it will stick again.

Jim Becker
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Re: #2 Exhaust Valve Sticking

Postby Jim Becker » Sun Apr 09, 2017 8:21 pm

Hopefully you were gentle with the tack hammer. There is probably a carbon deposit (or other crud) on the valve stem that is causing the sticking. The crud is not going to be uniform around the stem, probably causing the different behavior when the valve is rotated.

Eugene
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Re: #2 Exhaust Valve Sticking

Postby Eugene » Sun Apr 09, 2017 8:50 pm

Keep applying the solvent and working the valve. You might remove the valve cover and spray solvent on the valve stem.
I have an excuse. CRS.

LeoM
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1966 Cub w/ IH 1000 Loader
1958 LoBoy w/ Wagner 45 Loader
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1948 Super A w/ Finish Mower
1944 A w/ 3 Point Hitch
Circle of Safety: Y
Location: Central Florida

Re: #2 Exhaust Valve Sticking

Postby LeoM » Mon Apr 10, 2017 7:43 am

I was very gentle with the tack hammer. I did remove the cover and sprayed Kroil on the valve stem, as much as I could see. The valve spring appears to be in tact but it is difficult to really evaluate with the manifold in place. I started to soak the manifold nuts because it will probably need to come off when the spring compressor gets here. It looks like it may never been taken off before.

Is it uncommon to see either a broken valve spring, or even a weak one, or a bent valve stem ?

Jim Becker
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Re: #2 Exhaust Valve Sticking

Postby Jim Becker » Mon Apr 10, 2017 9:40 am

From my experience, the problem is almost always from contamination that has accumulated. Actual part failure is pretty rare (other than the need for a conventional valve refacing, which may include a burned valve or damaged seat).

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MAGNETO
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Re: #2 Exhaust Valve Sticking

Postby MAGNETO » Mon Apr 10, 2017 10:48 am

My cub had 4 valves sticking. All of them were due to 70 years of crud and gunk on the valve stem and in the guides. Remove the culprit valve, and use a brass brush to remove all the crud on the valve stem. I have a brass wire wheel in my bench grinder, works fantastic. Get a brass bore brush for cleaning rifles, and use this to clean the guide. Make sure that your brushes are made of brass, so as not to damage or scratch the valve or guide.
MAGNETO

bofahs
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Re: #2 Exhaust Valve Sticking

Postby bofahs » Mon Apr 10, 2017 3:30 pm

Once the valves get free, a dollop of Marvel Mystery Oil in the gas tank each fill-up might be called for. Back in the 90's, my exhaust valves had to be popped back into place a few times. I've used MMO ever since - never happened again. Correlation or causation? Don't know - not a scientist. But I still use it!

LeoM
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Posts: 112
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Tractors Owned: FARMALL FORUM
1966 Cub w/ IH 1000 Loader
1958 LoBoy w/ Wagner 45 Loader
1952 Cub w/ Woods 48" Bush Hog
1948 Super A w/ Finish Mower
1944 A w/ 3 Point Hitch
Circle of Safety: Y
Location: Central Florida

Re: #2 Exhaust Valve Sticking

Postby LeoM » Mon Apr 10, 2017 7:34 pm

Thanks to all.
I have brass bore brushes and Marvel Mystery Oil. As soon as I get the spring compressor I will clean the valve guides and check valve seats for contact.
I'll post an update after it's back together.

LeoM
Cub Star
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Posts: 112
Joined: Sun Dec 07, 2014 7:02 pm
Zip Code: 32713
Tractors Owned: FARMALL FORUM
1966 Cub w/ IH 1000 Loader
1958 LoBoy w/ Wagner 45 Loader
1952 Cub w/ Woods 48" Bush Hog
1948 Super A w/ Finish Mower
1944 A w/ 3 Point Hitch
Circle of Safety: Y
Location: Central Florida

Re: #2 Exhaust Valve Sticking

Postby LeoM » Sun Apr 16, 2017 5:30 pm

Some days you're the dog and some days your the tree. Today I am howling.

This being the first time I have removed valves from a flat head there was a bit of a learning curve. When I removed the keepers from the first valve I dropped 1 and it went straight to the crankcase. I got my extendable pocket magnet and fished it back from the oil pan through the opening in the casting next to the lifter on the second attempt. LESSON LEARNED. Cover all openings and remove the keepers with a magnet.
All valves are out and look to be in good condition considering the age. Some are pitted on the top and the lapping tool won't stick. I am thinking to use a whetstone to resurface them or maybe just replace the ones that are heavily pitted ????????

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MAGNETO
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Serial #25131

Re: #2 Exhaust Valve Sticking

Postby MAGNETO » Mon Apr 17, 2017 4:36 am

One of my intake valves was severely pitted, so I just replaced it. For all the more that they cost, its really not worth the time and effort to try and salvage those old valves, in my opinion.
MAGNETO

Stevetractor
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Re: #2 Exhaust Valve Sticking

Postby Stevetractor » Mon Apr 17, 2017 6:01 am

For what extra it costs you might consider a valve kit. Usually has new valves, springs, guides, head gasket, and valve cover gaskets. Have the seats ground while your in there and I think you will be much happier in the end. Just an opinion to consider. The machine shop can measure the old guides to see if their in tolerance. Rub your fingernail over the valve stems. If you catch an edge their shot.

LeoM
Cub Star
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Posts: 112
Joined: Sun Dec 07, 2014 7:02 pm
Zip Code: 32713
Tractors Owned: FARMALL FORUM
1966 Cub w/ IH 1000 Loader
1958 LoBoy w/ Wagner 45 Loader
1952 Cub w/ Woods 48" Bush Hog
1948 Super A w/ Finish Mower
1944 A w/ 3 Point Hitch
Circle of Safety: Y
Location: Central Florida

Re: #2 Exhaust Valve Sticking

Postby LeoM » Mon Apr 17, 2017 8:06 am

Thank you.


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