666not running properly

6BuchTractorRed · May 19, 2020

I installed new rings, pistons and rod bearings in my IH 666 gas but can t get it to run smoothly, sounds like it has a race cam in it. Took it to a dealer and they tried and checked everything but couldn t get it to smooth out either. They overhauled the carb., adjusted the governor, replaced the muffler, pugs and wires, replaced ignition modular, checked compression, adjusted valve c"earache. They attempte to set timing and found ignition as all over the place. Any suggestions.

Janicholson · May 19, 2020

A bad distributor cam bearing causes substantial timing variation because the shaft wobbles in the loose bushing. Even
electronic ignition can make that variability. With the cap off, wiggle the distributor toward the engine and away up and
down. If you can move it, it is bad. Also twist gently clock wise on the rotor. it should move about 20 degrees or so, then
spring back to where it was. if it does not, the centrifugal advance has failed. also causing rough idle and operation. Jim

David G · May 19, 2020

I would agree with Jim, but usually do, he is my mentor.

Steve@Advance · May 19, 2020

If the timing is jumping around, something is wrong, probably a worn distributor, improperly installed module, or a loose connection.

Something else to check, the exhaust manifold bolts to the intake, I believe. Sometimes the exhaust can burn through internally to the intake, act like a mystery vacuum leak. It would need to come off, fill the exhaust with liquid, see if it transfers to the intake.

Mark-Ia · May 20, 2020

Did it run alright before the overhaul?

6BuchTractorRed · May 20, 2020

I did get movement both in and out and up and down. Do I need to replace the distributor?

6BuchTractorRed · May 20, 2020

It was missing before.

6BuchTractorRed · May 20, 2020

I replaced the exhaust manifold.

J Hamilton · May 20, 2020

It sounds to me like it, but I would have
thought the dealer you took it to would
have checked the distributor if the timing
was jumping over the place

J Hamilton · May 20, 2020

I would pull the distributor and check the
pin that holds the gear in place on the
distributor shaft to see if it's loose too.

Janicholson · May 20, 2020

Yes. I think they sell them here on YT. Jim

Doug Wi · May 20, 2020

I've been having trouble with mine too. Runs abit then acts like it's starving for fuel. But good fuel flow. Problem seems to with the exhaust manifold. There is a spring loaded shaft on the side of the manifold that I assume is a heat regulator . Playing with it I found that the shaft needs to be in the full CCw position then it runs ok. had to turn the spring around the keep it in that position. So I am wondering if something is burned through there like another poster mentioned. haven't got around to checking this out yet Spraying with it and it keeps running. Another thing to check, but it doesn't sound like your problem. If you have the Marvel shebler [sp?] carb with the electric fuel shutoff, there is a tiny jet about the size of a pea screwed into the end of that. It doesn't come with a new shut off, have to change it from the old one. But then it runs like the choke is full out. I got mine at a consignment sale.It looked like the previous owners had just overhauled it, and that tiny jet was left out, and they could never find out what was wrong with it and just dumped it.

666not running properly

6BuchTractorRed

New User

Janicholson

Well-known Member

David G

Well-known Member

Steve@Advance

Well-known Member

Mark-Ia

Well-known Member

6BuchTractorRed

New User

6BuchTractorRed

New User

6BuchTractorRed

New User

J Hamilton

Well-known Member

J Hamilton

Well-known Member

Janicholson

Well-known Member

Doug Wi

Member

Similar threads