My 7 yr old got a Panther 110cc for Xmas. He's having a blast in the backyard and overall we're really happy with it.

I adjusted the carb needle down a notch for running cold weather and it's been starting pretty well. (Also adjusted the air mixture and idle speed per the other thread, here.)

To start, it doesn't need much choke, though I do need to feed it some throttle to keep it running until it runs for a couple of minutes. Then it idles fine (though maybe just a tad high) and runs very well.

Until about 30-40 minutes later. Once he's been riding for about that long, the idle starts to slow down, and then it eventually starts stalling when he comes off the throttle.

I can (usually) start it back up if I give it some gas, but it needs throttle now to continue idling. I don't want to adjust the idle screw up, because that just makes it run way too fast when I start it cold. (Once it sits for several hours, it starts pretty well and runs great, until it's been run another 30-40 minutes or so.)

It's only been in the high 30s and 40s during this. Is it possible I've got the carb needle adjust TOO rich to run well once it's thoroughly warmed up? Should I adjust it back down and just deal with having to work a little harder to get it started when it's cold?

Do I need to adjust the valves? Could I be having a clearance problem that only shows up once the engine is thoroughly hot?

What else should I be looking at? This is hard to troubleshoot because it's difficult to work on some things when it's really hot, and when it cools down, I don't have the problem. I'm virtually certain it's not a gas vent problem, as I have already enlarged the vents somewhat, and I still have the problem even with the gas cap off (short time only for testing.)

I've read of some folks having CDI problems. I don't know much about that. What does the CDI do, and it is it possible for it to be affected by this 30-40 minute run time, and would it correct itself when cold?

Thanks.

 

what way did you move the needle? if you move the clip up ( needle down)you are leaning. if you move the clip down (needle up ) you are making rich. if you were at center on needle I would try moving clip down one. you want it a little rich with cold weather

 

check the gas cap vent. I had an old honda ATC 200 and at first it would run 15-20 minutes then loose power and stall. Leave it sit an hr. and away I'd go. The gas cab wasn't venting on the tank.

 

Thanks for the quick replies.

Carb needle adjustment: clip down, so needle up. Should have been more clear. It's running richer for now. Will running too rich cause stalling problems once the engine is really warm, even if it's still cold (i.e. 40's) outside?

Gas cap: pretty sure that's not it, as I said. It will still stall even with the cap off, and I'd already enlarged the vents.

 

Did you change the oil before its first run?
We have seen them start ti seize up because of lack of lubrication.
The oil from the factory is basically swamp water.

 

Did that, too, thanks to this forum. [img]i/expressions/face-icon-small-smile.gif[/img] (Actually, "Santa" did it sometime Christmas eve.)

I pulled the sparkplug after my original post, and the ceramic around the electrode is broken. So, a new spark plug is a given, soon's I can find one. I'd prefer the NGK C7HSA, I think, but I'll settle for the Autolie 4194 as that seems to be what's in stock. Maybe that's all it was? Or is the sparkplug damage a symptom of another problem? Hmmmm.

 

Sure looks like it was the spark plug. I put in an NGK C7HSA. Also changed the fuel filter along with the fuel hoses. The originals were leaking just a bit. It idles much better and with about 45min-hour playing on it today, it never did slow or try to stall.

Do appreciate the pointers, guys. Thanks.