2 Stroke 1996 honda cr125 studdering at high rpm

A

Acoole

I just got the bike freshly rebuilt and it was running perfectly fine and then all of the sudden it started to get a studder in the higher rpm’s and it got worse and got a bit slower. I put a brand new spark plug in it, got a better connection for the ground for the coil and the wire for the boot and coil and it didn’t do anything. I cleaned out the carburetor and that did nothing too, i figured it’d be either spark or fuel because it has a brand new top end in it and still has good compression. The air filter is brand new and clean so it’s not clogged so I’m not to sure what’s happening any help will be appreciated
 

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SRAD97750

SRAD97750

Moderator
Staff member
Dang, sounds like you are on the right troubleshooting track.
Does sound like electrical issue based on your symptoms.
-BIG DAN:thumb:
 
jbird710

jbird710

I had an '85 CR500 project I sold a friend. After he restored it, he was having a similar problem. Never found out what it was as he sold it off to someone else before I had an opportunity to check it out.
 
fringebi

fringebi

It sounds like you've done a thorough job checking the common culprits—spark, fuel, and compression. Since the issue persists at higher RPMs, you might want to check the ignition timing, as misfires can cause stuttering at high revs. Another possibility is a failing CDI (capacitor discharge ignition) or a coil that’s weak under load. You could also inspect the fuel lines and petcock to ensure proper fuel delivery, as fuel starvation could cause this stutter. If everything checks out, it might be worth testing or swapping the ignition components.
 
A

Acoole

fringebi:
It sounds like you've done a thorough job checking the common culprits—spark, fuel, and compression. Since the issue persists at higher RPMs, you might want to check the ignition timing, as misfires can cause stuttering at high revs. Another possibility is a failing CDI (capacitor discharge ignition) or a coil that’s weak under load. You could also inspect the fuel lines and petcock to ensure proper fuel delivery, as fuel starvation could cause this stutter. If everything checks out, it might be worth testing or swapping the ignition components.
Click to expand...
So far I cleaned out the power valves throughly and that did nothing so I took the reeds out and there was a small gap so I’m waiting on reeds to come in the mail and put them in to see if that fixes it
 
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