M135 just not running right.....

[Brad]

It's me again. I hope you guys dont mind my questions. But I find you all a great help.
The M135 my Dad and I are working on just doesnt run right.
He had the engine rebuilt about 10 yrs back and it has ran very little.
It just seems to not want to take gas.
It idles fine but has trouble when accellerating?
I suspect a spark advance problem, but really cant tell.
Also sometimes it seems fine till its warmed up.
Do these coils ever act up like that?
Any help would be GREATLY appreciated.
Thanks again,
Brad

 

[Barrman]

Accelerator pump in the carb, gummed up carb or just the wonderful 10% ethenal fuel we are forced to run?

Yes, the coil could be failiing. When it starts to run bad, feel the coil. If it is just about too hot to touch, that is your problem.

 

[YkDave]

Coil issues will tend to act up after the engine has been runnign a while and the coil has warmed up. the heat expansion of the windings in the coil will cause a break in the coil windings to pull apart and start to arc, causing all kinds of issues.

Their are many possibilities as to what it could be.

Carb issue
Fuel pressure
ignition
cam timing
valve lash

Just to name a few

 

[armytruck63]

I agree with Barrman. We had a problem just like this when we did a tune up on a M37. The truck ran great for about 5 minutes, then started missing and died. The coil felt red hot. I suspect the coil was foreign made and might have actually been for a 12 Volt system.

 

[Barrman]

For the most part, a coil is a coil. The resistance at the coil is what makes it 6,12 or 24. 3 Ohms resistance and you have a 24V coil.

If yours is hot, pull it out and shake it. If you hear and feel sloshing around, then it is bad. good coils don't have the oil sloshing around.

 

[zak]

Somebody once said most carb problems are electrical.

 

[Mastertech]

Ya and these coils dont run at 24v they run at a 12v or less check your manuals the distributor has a resistor to cut the system to 12v and its a simple 12v points system from there. hope this helps.

Byron

 

[rosco]

I never mastered that carb. I carried an extra under the seat. Once coming back from a routine 350 mile trip, it took me two days to make it. It would idle, but no power at higher RPM's. So I started taking parts, one at a time, out of the extra carb, and putting them in the one on the engine. Never did get it to run right, so out of desperation, I put all the "extra" carb parts, back in the "extra carb", and swapped out the two carbs, and was able to drive the last 50 miles home at 55 plus. I never did figure it out!, but your symptoms, sound pretty close to home. I guess that my gut feeling was that there was an internal passage plugged! Good Luck