2008 jonway 150 Tach Missfire bogging problem By donhoe (Read 540 times)

[donhoe]

I read as many post's as I could and couldn't find anything similar so.. I bought this scooter last year new put it together ran fine..  put 1750 "miles" on it. got it out this year Ran fine to start with- Broke off a Mirror replaced it - I dought this has anything to do with my problem but I thought I'd throw it in as It's possible I somehow loosed or pinched  a wire in the mess that's behind the steering cowling. anyway what it's doing is-  Starts idle's fine Runs good for a mile or so till it heats up then The Tach will start going crazy- jumping up from say 4k to 6k or even 12k if I give it gas - the thing is I'm listening to the engine and it's not revving up it's dieing doun and if I give it more gas it will start to sputter and backfire a little. let up on the gas goes back to normal runs normal but cant get anymore than 35mph out of it. the longer I run it the worse the problem git's  alreadt replaced the Vatiator, clutch, belt, cdi. so I'm looking at cleaning the carb or sparkplug- possibly new stator- kind of lost though because I don't understand the Tach acting like it dose any Idea's would Be greatly appreciated. I Know This Has to ring a Bell With Someone. Thanks

P.S. even after It's really hot It will still Idle well and the tach will come doun and act normally when it's Idleing.

[jct842]

Why bother to clean the plug, just replace it. Have you adjusted the valves ? Those would be a good place to start anyway. Plugs can get an intermittent short from a piece of carbon and some times they get an internal that cleaning won't help. A lot of the time when valves are too close with close to zero clearance the start and run till the engine gets hot, things expand and the exhaust valve now doesn't close and engine quits. If the old plug checks out ok keep it for a spare, the new one will run better.

[cyborg]

Jct is on it,,,adjust valves,,,new gapped plug ,,,clean carb,,,,ride scooter,,,,,smile a lot,,,,,Edit,,,,coil may be on its way out,,,they get funky and do weird stuff when they get hot,,,,

[donhoe]

Thanks guys i'll give it a try!

[donhoe]

Just thought I'd follow up adjusted the valves to .005 each  (valves were to tight under .003) - boom! all problems gone runs great tach normal thanks!

[cyborg]

Great!!!! Thanks for the update glad you got it handled

[olivertwisted]

So there IS another 2008 Jonway 150 still on the road out there!!!!!
Glad ya got it worked out, donhoe !