D4-7u Pony problem

It definitely sounds like you've got a really dirty carburetor. Those carbs are notorious for having the internal passages plugged with the crud that accumulates over time, and when you said you've had to run it before with the choke closed it means the pony wasn't getting enough fuel then, and now it's getting even less. The only really good way to truly clean the carb is to remove it and completely disassemble then remove the round plugs that seal the internal passages and get the dried up crud out. There have been several good threads on here that will have all the details.

I have 5 ponies with 5 different personalities when it comes to starting, all carb related.

Generally you can clean a carb enough to get a pony to run by taking the top off the carb while still on the pony. It is quite a commitment to pull the carb and can result in considerable down time.

There are threads on here by guys that have drilled out the plugs and cleaned the passages. It would be good to have a sticky with pictures showing how to do this.

My guess is that problem with needing the throttle off as well as the no run without choke is going to require carb off "major cleaning", good luck.

There's a jet in the bottom of the carb bowl that is easily clogged. Remove the top off the carb. Soak the gas out of the bowl with a rag and then blow some compressed air in that jet. Blow in all the passages you see while you're at it. While off check the float level (top of float flipped over and measure from edge of metal to bottom of float). Don't have my book with me, but it's about an inch. Probably already a thread on this site that covers carb rebuild. I have four D2's and they are all different how the pony will start. One likes some choke. One no choke. etc.

If I am remembering correctly, that jet in the bottom clogged does give a symptom of needing the choke on to run.

There's a jet in the bottom of the carb bowl that is easily clogged. Remove the top off the carb. Soak the gas out of the bowl with a rag and then blow some compressed air in that jet. Blow in all the passages you see while you're at it. While off check the float level (top of float flipped over and measure from edge of metal to bottom of float). Don't have my book with me, but it's about an inch. Probably already a thread on this site that covers carb rebuild. I have four D2's and they are all different how the pony will start. One likes some choke. One no choke. etc.

If I am remembering correctly, that jet in the bottom clogged does give a symptom of needing the choke on to run.

Thanks for all the replies...I'm really not that concerned with the pony only running with the choke on , it's always been that way. What I would like to correct is that it will ONLY idle...give it a little throttle and it dies. while it is idling if I spray a shot of ether in the carb it revs right up. I guess at a minimum I'll be pulling the top off the carb and see what I can clean or open up in there. Thanks again, John

I have had good luck cleaning outboard motor and chain saw carbs by disassembling them and giving them in an overnight soak in mineral spirits followed by a swim in the ultrasonic cleaner again with mineral spirits. I did not pull any of the plugs for the hidden passages, just the easily removable parts.

Good luck,

Rick

All great info here but one area in my D4 Pony motor that gave me a big problem was the needle & seat. Make sure it isn't sticking or has dirt plugging the inlet off. The original Cat needles were aluminum and seldom stick but most aftermarket ones are rubber tipped and are OK for a year or two but will eventually give trouble like mine did. I found an old aluminum needle and never had any problems since. The aluminum needles may not seal quite as well as the rubber but you should shut the fuel off when not running anyway to eliminate any possible flooding.