Marvel Schebler - Idle Problem TSX-120 (Oliver 60)

Problem: engine will not idle. When the governor/throttle is set low it hunts. Idle air screw has no effect.

Vacuum seems good.

This message is also posted in the Oliver forums.

Any ideas, should I look else where?

Just went thru all this with my Hydro 70 (same derned carb).

Whenever you take the carb off, the first thing ya have to do after you put it back on is to re-syncronize the governor. This is what is causing your "hunting" problem.

Now, after all other adjustments are made concerning timing, etc., go back and set the idle. That "idle mixture" screw really only controls air so it is not going to feel right to you.

Mine runs best screwed out just 3/8 to 1/2 turn.

Allan

Thanks for the info. What's your procedure for re-syncronizing the governor?

Mine are Internationals so they will be completely different from your Oliver 60.

The procedure should outlined be in your IT manual. And, it will kill that "hunt" fer sure.

Allan

• Hobby farm

Take some time, and study out the hidden passages, and figure out how fuel gets from the main jet area over to the idle circuit, and you'll have the problem figured out. Likely, the hardened crud will have to be drilled out of the passage with a tip cleaner or tiny drill bit.

There are passages drilled in the cast iron that get so severely clogged a small drill is likely needed to clean them, and there is no harm in that, as long as the brass jets are not drilled out and harmed.

I only used the non-serrated portion of the welding tip cleaners. I didn't poke anything through the brass parts. Verified all passages clear using aerosol carb cleaner and compressed air. Took my time, several hours. Hard to believe I missed something, but I won't rule out that possibility.

Regarding the ignition system, it has new points and was static timmed, and then checked with a light. The plug wires are not solid or stranded. They are the resistor type, but I find it hard to belive they could be causing all the problem. The spark plugs are Champion D21's. New six hours ago. Sparking at each plug when wires are gapped.

Also with governor disconnected it dies. So I think that rules out governor rigging,

Good suction with hand over carb. Sprayed lighter fluid around manifold to check for leaks.

Make sure that you didn't miss the pressure balance port in the area of the choke. It's a drilled hole or slot and it vents the fuel bowl to the carb inlet so the air cleaner restriction won't affect the metering system. If it's plugged, your idle port will pull some fuel out and the pressure in the fuel bowl will fall and reduce the fuel flow.

ALso, pull a plug wire and see if you have fat bluish spark. That's about all I have to offer.

I agree with Bob that you may have missed a passageway someplace? Clean bowl and top mating surfaces well with steel wool seeing if you don't find a new plugged hole to clean out. If you are running those carbon core wires with a magneto get rid of them now! Okay on a battery dist. ignition but you will get more fire with metallic core wires. The hunting just sounds like carb problem to me yet. Make sure the new needle seat is sealing off good and float isn't bad or hanging up. New TSX floats can be had for a reasonable price and if float looks collapsed some replace it.

I'm running the resistor wires with a distributor. I don't think they're the problem, but I'm going to replace them with metal wire anyway. Spark is good 3/8 to 1/2 inch jump.