Hi all.

I've noticed the last few days (weeks?) a serious loss of HP under the 4000rpm level on my 99 R1. :machinegu

it's got 33000km (+/-17800 miles) on it and had it's last major checkup at 26000km (+/-14029 miles).

The valves were re-aligned (if that's the word) at that checkup.
The manual says that needs to be done every 24000km. So that was about right the last time.

which things should i see check :confused:
i'm thinking:
- spark plugs
- air filter

-zen

Yes sir check the plugs,air filter,fuel filter. Is it just bogging down or what:confused:

Is it just bogging down or what:confused:

bogging down? you need to explain that :confused:

the sound of the engine seems "darker" which it didn't do before. Especially when releasing the throttle i get "after-explosions"
apart from the great noise it's proof of a not so correctly running engine...

normally an r1 will start to wheelie above 4000rpm but now...nothing... when it gets closer to the max possible rpms it will wheelie a bit...

-zen

ok I gotca,pull the plugs out and check them first.Sounds like detonation.Pull the plugs and let us know what color the end is,white,black....

Hi, Do you still have the EXUP valve fitted ? In other words, the standard headers ? You may want to look and see if the EXUP servo motor is working properly and if the butterfly is not stuck open. If it's stuck open you loose lots of bottom end i.e. below 4000 rpm. If it is stuck open, it will not affect top-end.

I seem to recall a set of steps in the service manual to check and set the cables etc.

tl: i will check the spark plugs tonight and post again
sandman: yes i think i have the standard EXUP valve because i've never touched it and i don't think my dealer has either.

but messing with the exup sounds like a bad idea, i mean i'm not a mechanic. I'm a software engineer ^_^

Originally posted by Sandman
Hi, Do you still have the EXUP valve fitted ? In other words, the standard headers ? You may want to look and see if the EXUP servo motor is working properly and if the butterfly is not stuck open. If it's stuck open you loose lots of bottom end i.e. below 4000 rpm. If it is stuck open, it will not affect top-end.

I seem to recall a set of steps in the service manual to check and set the cables etc.

OOOHHHHHHHHH damn good call,I forgot about the EXUP:bash

sounds like the plugs could be worn out, or the carbs are blocked.

i had a similar thing on my zxr750 when a dead insect managed to get through the airfilter and block up the carb jet. The bike"s power dropped from 110bhp down to 70bhp.

another time i had a similar problem and it was the coils playing up on the bike.

first stop i think is to fit new plugs and check the leads/coil connections. Then check the carbs.

i checked the spark plugs and they are fine. top speed is fine too.
with the 2002 silver/black r1 on it's way :machinegu i'll leave it as it is...