People 150 engine cuts out from "high" speed

[smurray47]

Just posted this in the People 150 forum but then realized it might fit better here.

Hey folks,

I've seen a couple posts about this problem but no resolution. I just bought a used People 150 with about 3k miles, and the previous owner claims to have taken great care of it. It runs like a dream if I keep it below 45. However, after about 4-5 minutes of going 55+ mph, it starts behaving funny. The engine seems to lose power intermittently, like a bad shift would feel. It kind of jerks slower, then keeps going. The first time I had no idea what was going on, so I kept the throttle engaged, and it kept happening until it stalled. Since then, I've just eased off the throttle to 45-50 mph, and it seems to do better.

I've tested it without the gas cap on, but it still happens, so that eliminates some potential causes. I'm also relatively light (145 lbs), so I don't think the scooter should have a problem doing 60 mph with me on it.

Any ideas what could be going on? Dirty carb? Could this be a sparkplug issue?

Thanks!

Sean
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[MJR]

Seems like some sort of mixture adjustment but I haven't messed with carbs much.

[hypophthalmus]

I think the first thing to suspect with a used bike with this sort of problem is a dirty carburetor from storage.

[Mr. Paul]

I think the first thing to suspect with a used bike with this sort of problem is a dirty carburetor from storage.

+++1

[vespbretta]

We discussed and had these same symptoms recently at the German Kymco Forum with a Grand Dink 125.
Problem there was a thin (hairline) crack in the floating chamber. Possibly caused by overtightening the drain screw of the carburator´s floating chamber at an earlier time. In this case, best solution would be a new floatingchamber. Maybe it could be repaired also with J-B Weld metal glue or similar stuff.
But as also mentioned above it could just be some dirt in there as well.

Certainly a thoroughly inspection of the carb is advised.

[Redk]

When tuning for best top end performance, best to try a large jet size first.
Running too lean can quickly fry a piston.

A manual choke can be of assistance, because it will show if performance improves when partially on.
Newer models will not have this manual option.
Perhaps a piece of heavy paper, taped over a portion of the air cleaner element would approximate this.
With half or more of the air filter covered, the engine should perform normally at all lower speeds and progressively degenerate

Might be worth a try
redk