You should run it on compression for a bit before turning on the fuel. I dont think it is a fuel delivery problem. Main jet should stick out at 45 degree angle from the bottom of the fuel bowl. It should be labeled MAIN ADJ. I would start with going out 1/4 turn at a time. If it gets better then keep going until it gets worse. Go back the other way until it runs the best. If it runs worse right away go the opposite way. Do this adjustment at full throttle and full load.

Hi Team,
the pony carby main jet initial adjustment should be around one and one half turns open from the closed/seated position, adjust from there for best power without black smoke (too rich) or hesitation/spitting back thru the carb, lack of power (too lean)

As described above the main jet sticks up at around 45 degrees and has a Tee handle on the main jet screw stem.
Hope this helps.
Cheers,
Eddie B.

Thanks Eddie. That is exactly the information I needed. It sounds basically like a carb on a car so I will run it in until it seats lightly then back it out 1 and a half turns as a starting point. its supposed to be 39 on Saturday so I might be able to get out there and give it a go.

My D8 1H pony will only run with the choke completely on. It has plenty of power and the main starts right up. I have cleaned the carb many times. Can anyone tell me what passage needs to be cleaned out? I am guessing I will need to drill out one of the soft plugs to clean it.

quick update. changed oil in the pony. lots of coolant in it. tightened several loose cap screws around the block, set the jets to factory specs and started it. pony ran smoothly so I ran it in low for a few minutes with no compression then for a few minutes in high with no compression. ran just fine and a good rpm. throw the lever to half compression where it dragged some but I toyed with the jets got a good mixture and he pony leveled off again (still cant get it to run though with less than half choke). but as soon as I tried to throw it to compression the pony died just like always. checked the oil and it already has water in it. so I think at this point I should pull the pony motor and try to figure out where the coolant leak is coming from. I could just pull the head and check the gasket and see if there is a crack in the head, but I have some other issues with the pony like a broken stud on a coolant pipe that I cant get to since its on the inside facing part of the engine. I also need to pull the starter housing now because I think I have stripped the ring in it and it wont catch any longer to engage the flywheel. unfortunately since this is all outside in northern IL I may not get much more done until springtime now. ugh.

Yes should be a crack head and if I can help should have some spair

Hi Team,
I seem to recall that Mike Meyer and a few others had cracks in the cylinder block in behind the valve springs--could be seen via the valve lash cover on the side of the engine--seems Mike tried epoxy and it took several attempts to achieve a lasting seal--thought to be caused by expanding rust buildup in a thin area of the casting.
Cheers,
Eddie B.

Long time since my last post. Life keeps getting in the way of working on my project. I pulled the pony motor head this summer (thats no easy thing when its still on the side of the big engine). took it and had it magna fluxed and there were no cracks. I bought a spray kit to check for cracks on the top of the block and that checked out clean. I also checked behind the valve lash cover and it was completely clean in that area with no signs of coolant.

I drained the oil and it turned out to be mostly coolant. The head gasket was pretty grimy so I got a new head gasket and have it installed. Before I finish installing all of the other parts though, would a blown head gasket allow for so much coolant to go into the oil pan? I hope so because I am not certain where else it would come from and I would be left with pulling the pony motor completely.

The coolant maybe came from the big motor