IH 674 gas tractor - runs like %$#@...

[Howitzer]

My brother has an old IH 674 gas chore tractor (I believe it has a c200 engine).

The thing has ran like crap for years. He got the head rebuilt, put a carb kit in it and thing still fouls spark plugs like crazy. It spits and misses a lot. He replaced the distributor with a used one but that didn't seem to fix much.

He thinks it needs a replacement carb, I wonder if it has a worn cam shaft that might be messing up the valves or distributor timing. He has also in the past noticed it was having fuel ending up in the engine oil.

Any advice on how to proceed? He's scratched his head about this old tractor for too long...

 

[wore out]

A compression check and a cylinder leakdown test would provide a lot of info, and a timing light would show if the distributor and it's centrifugal advance are doing their jobs.

 

[rustred]

Well for starters the cam lift should have been noticed when setting the valves. Is the valves set correct to spec? Why do we never get info as to what was done and how things are or were set. U can throw all kinds of new parts at an engine , that still wont make it run if you dont know how to perform the job. Then the points are they set to spec? Is the timing set to spec? Was the carb soaked and cleaned properly. What spark plugs are in it ? Plug wires ok? Does it have a thermostat in it ? And me my first thing to do is a compression check , even though u said he did the head. And just running around with it not getting to operating temp. Fouling plugs will be normal. Is it an oil burner , theres another reason. A few things to chew on.

 

[used red MN]

Are the plugs oily with a somewhat wet black residue and a lot of accumulated carbon on them that means you are passing oil most likely up past the rings. Does it use any oil? If so, probably means that instead of just doing the head he should have went on and put rings in as well? If Or do the plugs. have a dry black powdery substance on then then it is likely getting to much fuel.

 

[Mike Van]

Gas in the engine oil - Bad fuel pump? How else could it get in there? Years ago my 574 [gasser too] was really running bad, i did all the easy stuff [plugs, points, etc] was getting ready to order a carb, about 200.00 at the time - A friend that i miss dearly was at my place one day, told me before i threw $$$ away on the carb to adjust the valves. Boy was he right - Tractors run fine ever since.

 

[Howitzer]

When we installed the rebuilt head, I believe we set the valve correctly, I could be wrong. We should reset them.

 

[Howitzer]

I'm hoping we set the valves correctly. We should set them again to confirm.

As for the points and timing, good question - we will have to confirm.

Carb - I believe we cleaned it pretty good and installed the carb kit.

Spark plugs - my brother has been using Champions, but has had to change them a number of times due to fouling.

Plug wires condition - I don't think he's changed them, maybe he should.

Compression test - we need to perform one.

Oil burner? Not that I'm aware of.

Thermostat? I believe it has one.

 

[Allan in NE]

If its fouling plugs, its pumping oil. Time for an overhaul?

Allan