YY250 T Now is a NO start. By kcohen67 (Read 655 times)

[kcohen67]

I have a 2008 YY250 T. First it started the "backfiring"thing and bogging down. Eventually it got to the point where it would bog down right after warming..and completely un-ride-able. I broke down and bought another carbuerator. I sounded just fine...untill it warmed up. Then it bogged down too. Now the bike just doesn't want to seem to start at all unless I remove the air box and cover the front of the carb. with my hand. I really need this bike running. Help.....

[richardthescooter2]

Sounds to me your running too lean, have you check all vacuum lines and intake clamps, make sure there is no leak, that will make you run lean, a leaking exhaust gasket can cause backfiring too

[richardthescooter2]

Also just thinking (that could be bad) what do you have your idle set at, a loe idle can also cause backfiring, should be set 1800 rpm's to 2000.

[Alleyoop]

This is what your carb most likely looks like and most likely a 30mm carb.
See the FUEL RATIO SCREW Turn that COUNTER CLOCKWISE to feed it more fuel. First Close it all the way CLOCKWISE do not force it just until it stops then TURN IT COUNTER CLOCKWISE
2 1/2 turns that is a good starting point.
Alleyoop

[tvnacman]

Could be a cracked intake manafold, I think Richard is going through problems with the manafild.

John

[kcohen67]

I appreciate your assistance Richardson. When I started the bike this morning, she purrrreeedd. It was after a ruff start, but she seemed to even right out. as far as the idle is concerned, the screw is back out...alot. Almost not even touching the throttle arm, and she still idled at about 2400. I adjusted the valves slightly and brought the idle down though. She sounded good...while she was running. Then...I shut her down for a while. When I went to start her back up I got nothing. I can see the gas misting out the bell housing, I checked the current at the cdi and the battery is giving me 13.4 v. Still...she won't start. I want to know how to test the coil or something. I feel like I'm not getting a spark at the plug or something.

[richardthescooter2]

When you turn key on, do you have any power at all? or does it crank but no start? Give us more info

[kcohen67]

Nov 16, 2012 21:57:11 GMT -6 richardthescooter2 said:

When you turn key on, do you have any power at all? or does it crank but no start? Give us more info

Yes she cranks very well..just won't turn over. I did all that I listed in the above message. I'm thinking though, while the engine was running I adjusted the valve settings (on the outside of the cylinder head). I shut the bike down. about 20 minute later I tried to start her again. All I got was crank. Maybe I should put the settings back on the cylinder head. I'll check it tomorrow.

And I'll check the Intake manifold for cracks too.

Alleyoop...why does your carbuerator diagram show the coolant lines -Not Connected- ?

[Alleyoop]

On the older scoots they used to have the raditor water run through there The idea was to warm up the carb, but did not do anything, as a mater of fact you can unscrew the little system off it is self contained it is just an in and out does not go into the carb at all .
Alleyoop

So you have the 244 helix upright motor then if the valve adjustment are on the side, here is a video on how to adjust them.

[kcohen67]

Allllrighty then! I adjusted the valves this morning and she turned right over. It's a good morning. Now...she DOES idle a bit higher than I'm comfortable with, but I'm thinking it maybe the jets in the new carb. I started with the 2 1/2 turns on the enrichment screw and placed the float cover back on. So...the more I turn it clock-wise during the adjustment (allowing more air) the higher the idle. I have it turned as far as it'll go counter clock wise, as far as the stops on the bottom of the carb will let me go (with the initial 2 1/2 turns) and the idle is still high. My throttle screw is BARELY touching the arm. Anyway, I haven't test drove her yet. I'm going to in about an hour.

I'm waiting to Fedex to bring me her lower panel replacements this morning. It's going to be a good day..

[richardthescooter2]

kcohen67, Glad you got it going. Idle should be 1800 to 2000 RPM'S.

[kcohen67]

Hmm...I just placed the knob of the enrichment screw to the left of the floater cover knob so I might adjust the enrichment screw clockwise, against the initial 2 1/2 turns. The screw now sits at about 2 turns. The RPM's are not going down. The idle screw is all the way out. Now what? The panels just came in. I'm to put them on while I evaluate the situation....

[kcohen67]

:-/After considerable thought, I've decided to change the idle jet.

Okay. I replaced the low idle jet, now she PURRRRRSSEEE like a kitten. ;D