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D8 IH pony motor stalls in high speed beyond half compression

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3 years 9 months ago - 3 years 9 months ago #224617 by kracked1
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.
Last edit: 3 years 9 months ago by kracked1.

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3 years 9 months ago #224623 by neil
Where are you located Brian? Might be a member within range that can come help

Cheers,
Neil

Pittsford, NY

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3 years 9 months ago #224624 by edb
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.

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3 years 9 months ago #224625 by BrianCamling
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.

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3 years 9 months ago #224636 by 8C 361
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.

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3 years 8 months ago #224785 by BrianCamling
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.

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3 years 8 months ago #224800 by gemdozer
Yes should be a crack head and if I can help should have some spair

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3 years 8 months ago #224812 by edb
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.

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