People S250 loses power with throttle wide open

[carrielsal]

I was looking at scooters for my daughter in college and test drove a 2009 Kymco People 250S at our local dealer. I've always ridden motorcycles and fell in love with the People, so much that I brought it home for myself! The first month I was mainly riding it on county highways with a top speed of 60-70 mph on the speedo and had no problems.

I finally took the scoot on a 600 mile round trip when I first experienced the issue. I'm hoping someone here may have some ideas.

I had been on an interstate for about 60 miles when I first experienced the problem. I had been riding about 80-85 MPH on the speedo and found myself been 2 semi's. I opened the throttle all the way and lost power (wouldn't you know it would occur between 2 semi's!) All the electricals were on, but it felt like the gas had been cut off. I let off the throttle and power came back at around 60 MPH. Since then I have found this is an intermittant issue.  With the throttle wide open or close to wide open (80-90 mph on the speedo), the scooter will lose power. All the electricals are still on, but it feels like the fuel has been cut off.   It I let off the throttle and drop the speed down to around 60 mph, power returns. If I pull off the interstate and completely shut the scooter off for a few minutes, the issue may not return at all; or the scooter will fine for a few miles with the throttle wide open then the problem start back up again. I can never tell for sure when it will happen. I have driven 100 miles and not experienced the problem, or had this problem within the first 5 miles of a trip. There is nothing I have found that will make the scooter do this. It can occur with the gas tank full, half full, or close to empty. I talked to the mechanic at our local Kymco dealer, and he has never seen this problem. I am concerned that if I take my scooter to the dealership, the issue may not occur when they test ride it.

Has anyone else experienced this problem?

Thanks,
Carrie

[Mr. Paul]

Sounds like it was over-revving and maybe the CDI limiter kicked in to protect her from blowing up. Does it happen when you are WOT on level ground, or just while going downhill or drafting behind other vehicles?

[TLRam1]

Mine has never done this but I also haven't ridden as hard for extended periods of time. I want to follow this and see what you find.

[carrielsal]

Sounds like it was over-revving and maybe the CDI limiter kicked in to protect her from blowing up. Does it happen when you are WOT on level ground, or just while going downhill or drafting behind other vehicles?

Sorry, not sure what WOT stands for. The issue can occur on a flat road with no other vehicles around me. There does not appear to be any consistency when the problem starts.

Carrie

[AMAC1680]

WOT, wide open throttle.

80-85mph even on an optimistic speedo is at the high end for a P250.
I'd be more interested to know what the revs and temps were when the problem occurs.

The P250 is a great bike but run that hard somthing is going to give.

AMAC

[hypophthalmus]

My non-S People 250 can very happily handle wide open throttle for much longer than that, even in 100 degree weather.

[carrielsal]

WOT, wide open throttle.

80-85mph even on an optimistic speedo is at the high end for a P250.
I'd be more interested to know what the revs and temps were when the problem occurs.

The P250 is a great bike but run that hard somthing is going to give.

AMAC

There's not an RPM display on the dash, and the overheating light has never come on. I normally have a headset on under my helmet to listen to music or wear earplugs. Yesterday I didn't have either on under my helmet. The problem started again 2-3 miles down the interstate. When the scooter started to lose power, I heard a noise a few times that sounded very similar to kicking an empty soda can that sounded like it it was coming from behind me on the right hand side.

Carrie

[Mr. Paul]

Was it on flat road or while going downhill or drafting behind another vehicle? If you are going downhill or drafting, the RPMs may go higher than the engine was designed. The scooter should maintain Wide Open Throttle on level ground without losing power.   I suspect the kicking soda can noise is unrelated and is most likely a loose attachment somewhere on the body or muffler. You just started hearing it because you are now able to listen. Try riding just under max throttle and see if the problem occurs. Best of luck to you and keep us posted!

[hypophthalmus]

My guesses are clogged fuel filter or clogged fuel injector.

[TLRam1]

These are carburated.

Wonder if what you hear could be a backfire due to lean conditions or something in the rear end going like a bearing or such. From what you describe, sounds more like a fuel issue and a backfire.
 

[ifican]

Any luck? I am experiencing something similar not exact but close enough. The last time this happened to me it was a hairline crack in the vacuum diaphragm and took me quite a long time to find. This behavior feels similar and acts alot like this one for you, just wondering if you found anything else as it also will be me another place to look.

[NigelB]

Hi Carrie
Do you have an update on this problem? I am having the exact same issue with my Kymco Bet & Win 250. And it's getting worse. I can actually feel that the bike starts losing power and then it just starts to bog down. It will idle fine or ride perfectly at a lower speed and then I can get up to full power again and the symptoms may or may not happen again. I removed the carb this weekend, sprayed carb cleaner everywhere, left overnight and sprayed out with compressed air. The diaphragm looks ok and there is no sludge buildup in the float chamber. Vacuum lines look good. Put back together and bam! 10minutes down the highway and the bike starts to bog down again.

Please let me know if you have resolved your problem - maybe it can help solve mine.

I have a carb from a donor bike which I am going to swap in in the meantime.

Cheers
Nigel

[ifican]

Had forgotten i posted in this one so good that someone replied. I have had two instances with similar though not exact behavior, wont go into details but will tell you what fixed it.

1) carburetor diaphragm had a hairline crack in the fold that was a pita to troubleshoot. Once i finally found it and replace it no further issues. (you can search threads and find it with much more detail).

2) another time it was the sparkplug, didnt make any sense but changed the plug and all disappeared immediately. Plugs are cheap you should always have a spare on hand, if its been awhile or you dont remember on plug change might be worth a check

[NigelB]

*SOLVED* After swapping carbs I had the same issue so decided to check out the inline fuel filter. Well what do ya know - that filter was so clogged up I could hardly blow thru it! The filter was an after market conical type bought at the local parts shop. Swapped over the genuine filter from my donor bike and all good now.

Researching this prob I found a bunch of good info on this forum, so thanks to you all for that. I hope my experience helps someone else. Next big job is to swap over the engine/tranny from my donor bike - it only has a few thousand miles on it while my existing scoot has near on 70k miles. Will leave it for Spring time (Oct here in New Zealand).

Enjoy the weekend everyone!