Jonway YY250T running problems By dklarz (Read 3,195 times)

[dklarz]

I bought a new YY250T 3 month's ago. Last week it started acting up by stalling when I stopped. When I got it started, I had to "pump the throttle" to get enough revs to sputter the 6 blocks home. After a holiday weekend out of town, I couldn't get it to start. I checked fuses, spark at the plug, fuel filter and fuel pump. All seem to be working fine. I removed the gas (I use 92 octane) and replaced it with fresh. I sprayed carb cleaner and got it to run for about 5 minutes, had to "pump the throttle" to get it to rev higher than idle (about 1800 rpm's) then it stalled. Won't start again. Any ideas where I should go next?

[bobf]

Let us start with which engine did you get? Vertical with 244cc or horizontal with 257cc.

Idle at 1800 rpm is about right. Set idle on the rear stand to just where the rear wheel starts to turn and then back enough for the wheel to stop.
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[kz1000st]

I'm voting for a bad fuel pump or vacuum line somewhere. Blipping the throttle raises and lowers vacuum which is how these pumps work. Check for a loose vacuum hose, crimped or cracked. Then try making a gravity fed fuel system with a bottle or hose to connect to the carb. If it keeps running, it's probably the pump.

[bhinch]

Could be the valves.....

[gatekeeper]

If your engine has the vertical cylinder adjust your valves this way: scooterdoc.proboards.com/index.cgi?board=power&action=display&thread=5025

If your engine has the horizontal cylinder adjust your valves this way: scooterdoc.proboards.com/index.cgi?board=power&action=display&thread=5032

[dklarz]

Thanks to all for the responses! As I'm new to this site, I'm pretty impressed with all the help...

bobf: The scoot has the 244 engine, supposedly a Helix clone. And, of course, the scooter is a Reflex clone. I have service manual for both the Helix and Reflex. No help with troubleshooting my problem.

That's exactly how I set the idle. Learned that from a motorcycle-owning brother.

kz1000st: I did check the fuel pump by disconnecting and cranking the engine. I'd get a intermittent spurt about 2 to 3 inches which is what I expected. Wouldn't that rule out the fuel pump? Is there a spec that I can measure with a vacuum gauge (like the old cars)?

I've also heard that it could be the carb - bad float or something. Don't know much about carbs - does that make sense?

I also found out after I bought the scoot that it isn't really new - it's a 2011 model - meaning that it probably sat in a warehouse for a couple of years. Could this cause problems that need attention?

[bhinch]

Welcome...I am sure that we can help you get your scoot running like a champ. No question is weird or fooless, we have all learned from the forums. Thanks again for coming aboard...

[warri0or15]

I have a 2011 jonway yy250t scooter. does anybody knows why the solenoid Is Getting overheated!!! And my Battery is not grabbing charged??

[intim2023]

my battery doesn't seem to be charging either so someone said it's the R/R whatever that is im doing more research now.