Cub Engine trouble.

Cliff

Cliff

Active member
Hello everyone.

I have a 1974 International Cub. Yellow White version.
I have several projects going on and I desided it was time to add to my tools and gadgets collection that could benefit from the addition of the new tool.
The new Gadget is an industrial endoscope.
The Cub engine in my 1974 cub would only turn 1/2 to 3/4 of the way then stop. I removed the starter and the bendix was locked forward. Hooked up to power and it worked as it should and the bendix disengaged as it should.
I went back to the tractor and the same rotation was of the engine was observed.
I removed the spark plugs and there wasn't any thing on the cylinders so no hydro lock.
I moved on to the endoscope and checked each cylinder.
#1. Both valves moved. One of them you could see moved in tiny surges or jumps.
#2. One moved smoothly up and down. The other was stuck open.
#3. Both valves stuck open.
#4. Both valves stuck open.
The cylinders from what I could see looked good. The valves and seats not so good. They all had a gooo on them and that rust that looks like a watery primer paint colored stuff as well as carbon chunks not many but there are some.
I am trying to figure out if it is woth the trouble and expense to do a valve job.
I have available an engine for a Cub Lo Boy 154 or maybe it's a 185 it will need a rebuild but I don't think the valves are as bad or bad at all.
I know it wouldn't be original but would this engine fit the standard cub?
If possible I don't won't make a Frankenstein tractor but if I dont have a choice I guess that is what I will have to do.
Any information or assistance would be appreciated.
Thank you.
 
stuck valves not that uncommon, pull the spark plugs and you can see the valves, oil them up and lightly tap them down , crank the engine and make them go up and will probably get stuck again, , keep shooting oil in the valve stem and turning the engine over, probably will come loose after a bit
 
tst said:
stuck valves not that uncommon, pull the spark plugs and you can see the valves, oil them up and lightly tap them down , crank the engine and make them go up and will probably get stuck again, , keep shooting oil in the valve stem and turning the engine over, probably will come loose after a bit
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Agree with tst's recommendations on freeing the valves. I would also remove the valve cover (easier if you remove the carb) so you can lubricate the lower end of the valve assembly/lifters. A lube spray like PB Blaster or KROIL works good. To reach the valves through the spark plug holes you can use a plastic soda straw as an extension for the spray lubricant to get to the valves that are stuck open. A hand crank is helpful to turn the engine C/S if you have one. When you get it all freed up check the valve clearance and adjust as needed while the cover is off. And a good supply of patience is very helpful!!! As for the fitment of a number series engine it's basically the same engine, might have to swap some external parts but it can be and has been done. If all this does not work and before I would consider an engine swap I would remove the head and access the valves for cleanup and possible resurfacing. You can do a decent job on the valves without removing the engine, only unkey and remove the valves if the seats are not pitted very badly. JMHO Stan
 
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I would do about as Stan suggested, but not in that order. I would start by removing the head and cleaning up whatever you find. Then work on freeing the valves. It also gives you good visibility to see if the valves just need freeing or if it needs a full valve job. You also get good access to see the cylinders to determine if you ONLY need a valve job. If more is required, I'd consider the 154 engine swap. But then, you say the 154 engine needs an overhaul, so what is gained by the swap?

I suggest starting with the head removal and cleaning because of your description: "They all had a gooo on them and that rust that looks like a watery primer paint colored stuff as well as carbon chunks not many but there are some."
 
Jim Becker said:
I would do about as Stan suggested, but not in that order................
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I completely agree with Jim Becker's logic and probably the best approach for the best long term outcome. The ONLY reason that I suggested the ideas that I listed was it MIGHT give you a quick fix to see if you can get the engine to turn over and start so you could do a better assessment of the condition of the engine. Probably going to have to remove the head sooner or later anyway which is IMO a lot more work (I hate the thought of broken head bolts, I've had some bad experiences there)!! Stan
 
Cliff said:
I know it wouldn't be original but would this engine fit the standard cub?
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Hi,
I would try to repair the engine the Cub has.

The offset Cubs use a pilot bushing in the rear end of the engine crankshaft, for the front of the long clutch shaft, that goes from the engine to the transmission.
They have said on here that the numbered series Cub LoBoys, 154, 185, don't have a pilot bushing. There is no pilot bushing there. They have said that only the early 154s have a hole drilled in the end of the crankshaft. After some time IH stopped drilling the hole in the crankshaft.
So, no the engine won't work in an offset Cub if there is no hole for the pilot bushing.
Below is a picture from TM Tractor Parts of the pilot bushing in a Cub crankshaft. :)
 

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Glen said:
Hi,
I would try to repair the engine the Cub has......
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Agree, probably the least expensive and quickest route.
Glen said:
........So, no the engine won't work in an offset Cub if there is no hole for the pilot bushing........
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Practical? NO. Possible? YES, depends on your desire, patience and pocketbook..... Someone once told me that "you can have almost anything if if you can stack the $100 bills high enough"!! :cool: :giggle: JMHO Stan
 
I also think you work with what you have. Stuck valves are not that bad. In addition to the top, you can also work the valves from the valve cover.

If you cannot get the valves loose from the spark plug hole or the valve cover you can pull the head. This is a post on my adventure with valves and doing a top end https://farmallcub.com/community/threads/installing-valve-keeps.93111/

All of this will be less costly in time and money than a rebuild and engine swap
 
Bendix teeth are clean ; as well as flywheel teeth?
No dead mouse that got pinched 's residue?
Bendix can ride freely where it's supposed too without binding? Spring is good too?
Starter alignment is spot on and the starter isn't off from the correct angle of the dangle?

You could clean and lube existing valves.
How did they get wet? What is the condition of the oil they are recieving can be asked too at inspection.

I had rain get in a set that sat. Not the first time freeing stuck valves on it.
After getting those stuck freed ; another stuck. And I knocked the keepers off it.
Umm hmm. Getting close to valve work time.
 
154/185 didnt have a starter either---the generator was the starter! --- I think its a REAL problem to put a starter on the block from what i heard!! just rebuild the motor in the cub and never look back!
 
SONNY said:
154/185 didnt have a starter either---the generator was the starter! --- I think its a REAL problem to put a starter on the block from what i heard!! just rebuild the motor in the cub and never look back!
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Just like the generator/starter on my 1973 Cub Cadet. Did the generator have any problem turning over the 154 Cub engine?
 
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