Won't rev over 4000rpm only on the road

[Dominik]

Hi
Firts i must say my english is bad sorry
2 weeks ago friend of my give me 81 xs650, 2k miles, was a project bike and i put al parts togheter, change oil, clean carbs, change sparks, clean tank, new battery, check timing, check charging! Everything looks like new and works perfect! First time start bike and starts at the very first try was happy so much, adjust litle carburetor and engine was working smoth, on neutral rpms are going to to end and everything is perfect, problems starts when i ride first time, bike cant pas 4000rpm on any gear i stop and check on neutral, and run perfect, now i dont know where i shuld start working to eliminate that problem, if anyone here can help, please
Also i wanna say thank you everyone on this forum for sharing yours knowlegde
Thank You
Sorry about my english

 

[pamcopete]

Dominik,

Try unplugging the regulator / rectifier.

 

[Dominik]

Thank you, gonna try this afternoon

 

[jayel]

carb diaphragms may have holes in them and not lifting at higher throttle settings

 

[drewfunk]

Check your spark plugs as well, they might be struggling under load.

 

[Dominik]

Hi
Spark plugs are new, im gonna check regulator and carburator tonite.
Thank you so much

 

[Dominik]

carb diaphragms are perfect, fuel level is ok, check without regulator and still the same issue, plz help

 

[Tomterrific]

Pull off the pod filters and see if it revs out.

Tom

 

[Dominik]

I did this before

 

[Dominik]

Any other ideas?

 

[nj1639]

What MPH are you getting at 4000 RPM in fith gear?

I see you live in Usa ........wear the fox hat?

 

[retiredgentleman]

Could be that your clutch is OK in neutral, but is slipping when in gear and under load.

If the clutch was apart, did you index it correctly?

 

[Dominik]

About 60mph at 4000 rpm, didnt do anything witch clutch, clutch fel ok

 

[nj1639]

Do you have stock gearing?

 

[Dominik]

Yes i think, never do anything with that

 

[Dominik]

I found a problem, was a rubber plug in carburator thank you everyone for your help! Thank you