Johnway yy250t-2 By bkbray (Read 843 times)

[bkbray]

I need some help just bought this scooter and it will idol but when you give it gas it just dies until it gets warm the guy I got it from said he rebuilt the motor but was not for sure on the vacuum lines and it has no air box just a small filter on the carb

[cyborg]

I would imagine with the open filter it's getting more air than it would normally,,,so there's a lean condition till it warms up

[bkbray]

Can I put bigger jets in the carburetor

[cyborg]

Yes get th next two up,,,try the very next number up,,,then if it still stumbles the next one up again

[bkbray]

I’m so lost I ran the vin number and to come back as jmst 125t-7 I just can’t figure it out
It has three different number one part of the plastic says yy250t-2 and the other says jsd250t-2 but the vin don’t match but I took the head off and it’s a horizontal 244cc

[cyborg]

Wow that's crazy,,,obviously someone has bin playing with it,,no matter rally I'd still go up a jet size,,,id also giv th auto enricher a look see,,,it may not be functioning correctly,,,lots of auto choke problems on th forums over the last few years

[bkbray]

I order new everything and advance cdi hopefully I can get it running

[bkbray]

What’s the best way to delete the air box

[cyborg]

Open filters are fine you'll have to rejet to get the mixture back in line,,,I'd do the exhaust also as long as you're doing it,,,you'll gain a few hps

[bkbray]

I got a Pro-Formance carb I don’t want to spend the money for a new filter box and filter they cost more than I paid for the scooter is there anything I need to do with the vacuum lines there are two that wasn’t hooked up when I got it

[cyborg]

You'll Ned to reconnect the automatis fuel valve to get gas to the carb,,,generally they com off Th intakeplugg manifold,then you hav to search where th other one comes from if it's not necessary just plug it and TI it off to the frame out of the way

[kcohen67]

I bought a Jonway Y250T as a project bike. I have WHITE Spark, GOOD Starter, and good gas, but STILL it won't start.
I replaced CDI, coil, battery and spark plug. I rebuilt the Carburetor and head.I got it to start, but the Idle was rough and white smoke poured from the exhaust. I noticed the flange the carburetor was connected to had a broken broken bolt so I extracted the bolt, resealed the flange, now it won't start at all. Tried adjusting Carburetor air/flow mixture. After about the fourth cranking cycle I hear the Carburetor cough a bit, but that's it. Any suggestions? Jonway Xpressway 250cc Project I'm new to these boards, and not comfortable with navigation here. Please excuse my clumsiness. I don't know how to post yet.

[cyborg]

White smoke in the exhaust gas means blown head gasket or a cracked cylinder,,coolant is getting into the cylinder

[kcohen67]

I'm hoping that was just a bad head gasket. I've since replaced that. The owner before me replaced the fuel pump with an electric on. The petcocck doesn't seem to be connected anymore. I just reconnected the line going to the intake manifold. Didn't help start the bike though.

[cyborg]

Pull the plug check gap and dry it or install a new one,,,it's probably fouled,,,I forgot to add while the plug is out turn the engine over for a few seconds with the plug out,see if any liquids come out the plug hole