General update and want advice, my Model 70

[LAWN BOY]

I had my IH Cub Cadet 70 running for the 2nd time tonight. It would appear I have a bad exhaust valve as there were flames in the muffler. ? Also the throttle cable doesn’t always work. I don’t know if the problem lies in the throttle cable assembly or my rebuild job on the carburetor. I’ll have to dig in and find out. It was smoking for the first 5 minutes of running like it did last time I ran it as if it was burning oil, then it cleans up and runs pretty good. I did check all the cylinder head bolts since it has already been through 1 heat cycle before. I did change the oil. I guess the engine might need to be rebuilt as my Winter project this year, but I’m going to run it as is this Summer and see how things go. It wants to die and doesn’t move like it did last time when I put it in 3rd gear. If anyone has any advice, I’d appreciate it.

[greg r]

I would check valve tappet clearance and timing for flaming exhaust. I had one engine that would turn the exhaust cherry red under heavy load. I set the timing correctly and it didn't do it again.

[LAWN BOY]

Ok. I’ve never done that before, I’ll have to do some research.
The flames are present almost all the time, it doesn’t have to be under load like your’s did.

[LAWN BOY]

I watched a video on adjusting valve tappet clearance. I plan on doing that this winter. I'll be running the tractor as is this summer, not very often though. I plan on having a compression tester by the time I do all this.

[finsruskw]

Compression test is a futile effort as these little Kohlers have a compression release that kicks in about 1/2 way through the compression cycle under low revs present when cranking.

Remove the spark plug and hold your finger on the port and you will tell if it has compression, and you can also hear it as well.

You will need a couple new gaskets for the breather ass'y to set the valve lash as well as a feeler gage set.
Any small engine shop should have these gaskets in stock