250 1988 yz250 build

Mihylo33

Mihylo33

Something isn't right here at all.
Disconnect the carb frim the boots and turn it sideways. Be sure that the carb slide is fully seated. Also is there a needle in the slide? Is there a main jet installed???
If you had an air leak. This bike would surge. Instead it runs wide open.
Like this bike.


 
L

Lovespeed

Mihylo33:
Something isn't right here at all.
Disconnect the carb frim the boots and turn it sideways. Be sure that the carb slide is fully seated. Also is there a needle in the slide? Is there a main jet installed???
If you had an air leak. This bike would surge. Instead it runs wide open.
Like this bike.


Click to expand...
It doesn't idle wide open like that but it does rev pretty high in the rpm's. It doesn't surge, it's like it starts out normal and and quickly goes up in rpm
 
L

Lovespeed

I'm not even gonna bother posting a video because I went out there just now and cranked it and yes... This time it was wide open! But it's weird because the throttle was in? Could there be something missing in the carburetor?
 
SRAD97750

SRAD97750

Moderator
Staff member
Lovespeed:
I'm not even gonna bother posting a video
Click to expand...
Do post a video. I can identify lean rev vs throttle rev.
What you're looking for won't be obvious. It only takes a couple mm of throttle opening to make an unloaded 2T scream.
Maybe the throttle cable is a bit tight, or slightly mis-routed? When the bars turn, the cables can get caught on different things and pull the throttle slightly.
Even at the carb where the cable enters the cap. The sleeve can get dislodged one pull, and reset itself the next. Giving you inconsistencies. Make sure the sleeve isn't getting hung up.
I've had this problem many times before. My 89 has a nut/block for the number plate that catches sometimes. My solution is to secure the cable sleeve to the bike so it can't be pulled. -BIG DAN:thumb:
 
L

Lovespeed

Here's the video. It's short because as soon as I started it I got scared and cut it off, but you can tell that it's definitely wide open. At least the kill switch works!
 
Mihylo33

Mihylo33

SRAD97750:
Do post a video. I can identify lean rev vs throttle rev.
What you're looking for won't be obvious. It only takes a couple mm of throttle opening to make an unloaded 2T scream.
Maybe the throttle cable is a bit tight, or slightly mis-routed? When the bars turn, the cables can get caught on different things and pull the throttle slightly.
Even at the carb where the cable enters the cap. The sleeve can get dislodged one pull, and reset itself the next. Giving you inconsistencies. Make sure the sleeve isn't getting hung up.
I've had this problem many times before. My 89 has a nut/block for the number plate that catches sometimes. My solution is to secure the cable sleeve to the bike so it can't be pulled. -BIG DAN:thumb:
Click to expand...


I'm wondering if it might be missing the slide spring.
 
Redordead89

Redordead89

If you're having probs adding the video here then post it to YouTube and add the link via the paper clip icon button above the reply text box, 7th icon from the left!
 
Redordead89

Redordead89

Mihylo33:
Something isn't right here at all.
Disconnect the carb frim the boots and turn it sideways. Be sure that the carb slide is fully seated. Also is there a needle in the slide? Is there a main jet installed???
If you had an air leak. This bike would surge. Instead it runs wide open.
Like this bike.


Click to expand...
Wow don't believe he thought it was a good idea to engage a gear! :crash::lol:
 
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