I have cleaned up my fuel delivery problems, but can’t get the pony to run correctly. The pony starts OK when cold, but when warmed up, or if the main has been running for a while, the pony starts, but will not run up to speed. The best way I can describe is it acts like it is not firing each time. I know I have good spark, pulled plug wire off each side when running like this and motor will change to running on one cylinder. Other things which I have noticed are; the dip stick wants to blow out when running, the oil filler cap if not screwed down tight will move up and down when the pony is running, and lastly, while try something different and trying to feed some fuel down the carb, it the fuel blow back out of the carb. From what I have observed, I think that I’m getting leak by the rings, and possibly the valves. I did a compression check, and at the first stroke of the cylinder got 62 psi, on next would bump to 90. It was the same on both cylinders. Went ahead and removed the pony, and pulled the heads. Cylinders walls very smooth (glass like) but don’t show any noticeable ridge. As long as it is out and this far, I’m going to hone and install new rings and touch up the valves. Has anyone run into the problems as described? Any help is appreciated. Tim

Check your bore/piston diameters.....may have already been honed beyond specs. Also check for weak valve springs....valve stems may have been ground to many times and/or could be sticking.
Severe blow by is usually a result of excess cylinder clearances.
Good compression at low speed and not a full rpm usually a valve train problem.
Course there are other things to check like finicky carb, governor not functioning, linkage problems etc. etc.

Thanks Old Magnet. I spent way too many hours taking carb apart, cleaning soaking, double checking all the passages, so I'm resonably sure it's OK. The gov, and linkages also seem good. Rings and gasket are on the way. Will start there. I keep telling myself that this a play tractor, with a few hours of "real" work thrown in each year, however when it doesn't go when you want it to, it no fun at all. When I get further apart, I'll post more info. All good sugestions, and will check over as well. Tim

I have one of those too! It's so near not running that when I first started it, it wouldn't start until I had changed the gasoline diluted oil out. Not a bad idea anyway, but it illustrates how a very worn pony will run, but hardly do it's job.

Could be valve clearances since it is worse when warmed up, though the blowby points to wear. I would think if it cranks up. it would be better on the cylinder/ring clearances when it got warm because of pistons expanding from the heat more than the cylinders do.

What does the exhaust look like? Can you make it black by choking it or over richening the "load" adjustment (screw it in to richen the mixture)? If not, you still have a fuel delivery problem.

I can make black smoke when choking out. Whitish smoke when "almost" running. I have to be pressurizing the lower half. I can think of any other way for the dip stick and oil fill cap to want to blow out. After looking at the valves, there still in the head, I can see a ring all the way aroung, but that doesn't mean that they have the proper cleearance. They could be hammered in enough that when hot will not seat correctly. Going to keep after it this week, hopefully get it back by fort of July. Thanks for the info, Tim

I think your poney run too hot you should check the water hole in the block and the head you should have a bad circulate.