250sx wont stay runnin on throttle

[mark38090]

I just rebuilt the carb and put in a new plug but whe i hammer the throttle it dies. Can't save it either, it totally dies and usually tkes 5 or 6 kicks to fire back up. Also what are your opinions on twist throttles vs. thumb throttles. This twist throttle is a pain in the @ss when it starts slidin, can't seem to keep from gassin all the way when it does...

[tapper190]

I would pull the carb apart again, sounds like dirt or somethings outa place. I would go with thumb thottle, they put it on there for a reason

[Tri-ZNate]

if you slowly rev the thing to full bore does it cut out after about 1/4 throttle?

[mark38090]

if you slowly rev the thing to full bore does it cut out after about 1/4 throttle?

No, If I rev slowly it's fine...

[Somekindofjerk]

Does it smoke when it cuts out? real black or anything?

[mark38090]

No smoke. just acts like I hit the kill switch...

[theonlyjosh]

did you hit the kill switch?

[mark38090]

Well I just got back from a 16 mile ride and it only shut off once. So I'm thinking maybe just a little dirt in the fuel line still, or something along that line. Anyway since this is the first time in 6 or 8 years it's been running I guess I should expect some bugs. Thanks for the suggestions. :w00t:

[hossola]

Hello. I have an 86' 250SX too. I just bought it. I cleaned out the carb real well and it sparked right up. my bike dies though after i ride a full speed for about 15 seconds. It has to sit for about 5 minutes before it will start... Any idea why this is so? It also will backfire before it dies.

[haggard 2hundie]

backfiring could be a lean condition or air leak somewhere , i would clean the carb and maybe go larger main jet i had the same prob with my 200X new carb bigger main jet and repaired intake tube (it had a tiny crack) runl like a champ meow


twister all day. it feels wrong for me to use a thumb throttle, i feel like im not hanging on to the bar as well