dying when hot By kalee (Read 1,286 times)

[kalee]

I have a 2011 Jonway YY250T motor scooter and it has 235 miles, after the temp gets up past half way it will die taking off at a intersection. When I stop at a red light and sit an wait for it to change to green ( it will sit there an Idle fine ) then I start to take off it will die maybe three times before I get thru the intersection once thru then it runs great. I can open up throttle and it will get up run go

[Alleyoop]

First thing I would do is Adjust the valves even though it has only 235 miles. Some come from the factory to tightly set and with the heat they expand and have trouble holding low rpms.
Also check the oil make sure it is not low on oil.
Alleyoop

[kalee]

I did readjust the valves and made it worse, so backed valves back to orignal setting. It came frome the factory with a setting of 8 on exhaust & 7 on intake, this bike has an exterior valve adjustment and I counted the marks on adjustment bar

[Alleyoop]

Ah, so yours has the HELIX vertical motor. How is the idle what at what rpms is the idle set at. It should be set around 1800-2000 rpms. Also on the stand as it is idleing does your rear wheel spin. If it does that means the idle it to high, you want to set the idle so the rear wheel just wants to turn or turn very slowly.
Alleyoop

[kalee]

Thats the way my idle is set now, myself an a neighbor put this bike thru a test on my patio. We got the temp up past half way and simulated like I was coming into a stop light and it worked okay three times in a row. I put it all back togehter and went for a test ride and rode approm.8 miles and the first red light I came to it done the same thing again died twice before I got thru the light. It finally quit running on me altogether and I took it to the local Honda dealer for them to fix I will let you know what I find out.

[jct842]

Going back to valves, if it was worse when you set it, I would still go back to that.
That is telling us some thing and am sure the honda dealer will find it.

[imnts2]

I still want to insist you get a compression gage and test the compressionn pressures. And overhead cam engine does not change valve cleanance much with changes in temperatures. Some people confuse .04" for .04mm. not the same. I mm is 1/25 of an inch. ( about)

A little valve noise is OK for awile. rather have a little noise to eliminate the possibility of to tight which really will screw up idle. Particularly an intake valve just a bit tight.

cheers Lefty2

[Alleyoop]

The other thing I was going to mention after the valve adjustment If it is still dropping the idle and dieing one ofther thing that will cause that is running really rich. The Fuel Ratio Mixture is not set right and will flood it out.

The Fuel Ratio Mixture should be set to get the HIGHEST IDLE on the center stand and if the rear wheel is spinning lower the idle using the IDLE SPEED SCREW.

If that is ok then the other thing that may cause that is the motor is loosing compression when hot.
Alleyoop

[kz1000st]

The CN 250 has a knack for cracking the intake manifold. I would start the scooter, squirt WD-40 all over the carb and intake manifold and see if the manifold is leaking. The idle should incease if there's a leak. The problem you're describing sounds like a vacuum leak to me. Under load the carb isn't getting enough vacuum to lift the slide and that could be why it's dying.

[kalee]

The company told me to remove the one with the rollers in it, I did, didnt find any flat spots cleaned it up and installed new grease then put it back together then installed it back on the bike. Now I will be able to remove clutch housing after watching this video, THANKS for the info.
Now I need a video on how to remove the rear wheel on a 2011 YY250T.

[Alleyoop]

Here you go:
Question Kalee, why are you reporting the post to the mods? Go to the TOP and CLICK on your MESSAGES to read your messages.

Alleyoop

Part1:




Part2:

[kalee]

Thanks alleyoop for the video, I had this pretty well figured out but needed a little reassuring I was on the right track.
kalee

[Alleyoop]

Great, glad I could be of help,
Alleyoop

[LUKE]

what? you spent $4k for a Roketa??? and now your'e fixing it? you couldve bought a Piaggio MP3 with that amount...anyway,,im sure that scooter works just fine for you...i like the color though

[LUKE]

Mar 27, 2013 12:44:32 GMT -6 Alleyoop said:

Here you go:
Question Kalee, why are you reporting the post to the mods? Go to the TOP and CLICK on your MESSAGES to read your messages.

Alleyoop

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maybe ,he doesnt trust the members,, LOL,, you can trust me, i can help you dude!