Stumped on Oliver OC3

dozerjoe

New User
Ok I must be losing my touch (if I ever had it to begin with) I've had many OC3 crawlers in my time that didn't run but this one is really got me Baffled, I recently bought this OC3 in really nice condition sitting in a barn for several years, had an aftermarket carb on it but I also got the original carb. Put a rebuilt mag on it, got good spark, the governor was not working, we took it apart and cleaned it out lubed it up, Got it running finally and governor seems to be working good, when I start to drive it which puts it on a slight pull the governor opens up the throttle from idle but it chokes out and stalls, the choke is open, has no power, changed the plugs, checked compression, all good, checked the plug wires for correct firing order, just has no power, even tried the original carb on it after cleaning it all out. does the same thing. Thought it was starving for fuel but if I squirt gas in the carb when it wants to die out it kills it quicker. Tried moving the mag to time it but it doesn't make any difference. I'm Stumped on this one. Stumped Stumped Stumped
 

Fuel, spark, air. Is the air cleaner restricted? More gas requires more air to burn. Just a thought. I've had tractors that gain water in the oil bath air cleaner and bog out just like you describe.
 
My OC-3 has behaved similar several times, ended up being a weak coil in mag. Will idle fine but no power at all- but usually occurs after running fine for 10-15 minutes. Also check venturi in carb, I have seen some that could be installed backwards and cause similar issues. Another thought- If it has been sitting for a while maybe valves are sticky and not closing fast enough when rpm's increase? I know that's a long shot but it happened to me with a Lincoln welder.
 
You seem to be competent enough and I am taking it that you have checked all the normal things first,fuel supply,compression,timing and spark,it sounds like it's a lack of fuel issue,I would check the function of the governor,if it is the case that the governor is turning the throttle shaft too far,instead of opening it up it would be closing it and shutting off the air,second thing the manifold could be drawing air if it was cracked or a gasket had failed,will the engine throttle up and down as it should,what about the gas,is it the old gas or have you flushed out the tank and refilled with new,that old engine would need leaded.
AJ
 
Had an after thought,most of the OC's I have seen and that's only a few as I am in the UK had straight exhausts if yours has a muffler it might be worth while if you took it off for a try in case it is restricted or if it is a make do and restricting the exhaust escaping,I have seen that happen a few times over the years mufflers rusting up inside and getting blocked,rodents squatting there and the air intake.
Hope you can get it sorted. AJ
 
This is going back about 60 years. My second tractor was an Oliver HG. It came with a Marvel Shebler carburetor. No way would it run. I replaced it with a Tillotson and it ran fine.
 
Is your spark a nice blue/white that jumps a 1/4 inch gap or more at all the plug wires?? Also if you pull the carb drain plug do you have a good flow of gas that will fill a pint jar in less then 3 minutes?? Have you tried to run it with out the air cleaner hooked up??
 
Adding extra fuel says it has too much already. Is the exhaust black smoke? Check for restriction in air cleaner and all tubing to the carb. Also tubing to the air cleaner, i.e. wasp or bird nest.
 
Well did you get your Ollie running right,what was wrong,it will help others if it should happen theirs if you post the cause and how you fixed it.
P.
 
I actually didn't get back to it, I've so busy recently, been on some business trips, I recently put it up for sale as is, just
have lots going on but thank you everyone for the suggestions and concern
 

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