I have an NSR 250 MC21. I recently had new pistons
and rings installed in the bike and it is now having problems. To start
with, on the first ride it was going great, then in mid flight the bike
lost the spark. When I turned the ignition back on the oil light would
not come on and the RC valve motor would not wind up like usual the other
electrics (all the lights) were still working. After stripping the
fearings off and tinkering around it all came good with no reason why.
This scenario has happened approximately ten times now, and it also
happened without the bike running. Now the RC valve motor does not work at all.
I believe the RC valve cables were far too tight. I have gone through all the relevant wiring to check for bad connections and faulty wiring and all appears to be fine. To fix the problem I need to find out what part has or is causing the fault, and I am told the only way to do this is to swap my parts with known working parts. Is this the only way to check (by swapping parts)? If it is the PGM3 can it be fixed?
If it is the PGM3 can i just install a new one to fix the problem or is it more involved than that.
I live in Brisbane Australia. Is there any one close by?
I Know there are a lot of questions, but i will appreciate any help.

No expert but it sounds like your servo to me, When you put the barrels back on you may have made the wires to tight making the servo burn out, you need to look at the tunning section and workshop on this site itll help, But id guess your servo has gone if its not working at all, you can get a second hand one from www.tyga-performance.com or put an add up here to see if anyone has a spare?

without a doubt someone with more mechanical know how will be along soon. but thats my guess

Cheers

Thanks for your response. Do you know if there is aney way to check the RC servo and posibly fix it? also is it posible the the PGM3 burnt and not the RC servo or will the servo go before the PGM3? The reason I am asking is I have no free access to other parts and was thinking I should purchase a servo first and if that does not fix it than I will get a PGM3.

Cheers

most times on the 18/21 when the RC valve packs up its down to a sticking or badly adjusted RC valve blowing that side of the PGM
the servo is only a motor you should be able to put a feed and earth to it to test it. disconnect it first, wires and cables.

If you want to check the PGM for burnout, remove the tailpiece and the PGM, then take the lid off the PGM and check the rubber goo for charring marks. If you see any evidence of overheating, then DO NOT run your bike until you've solved the issue. You will destroy the PGM.

Assuming the best, and that the PGM is only just gone, then it is possible to replace the transistors which supply the current to the servo motor.

Take the lid off, and post us a photo of the insides. From that we should be able to tell you if it's toast!
_________________
MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

It seams I have some good and some bad news. The servo motor appears to be working fine. The bad news is there are two transistors (I think) that are burnt. I have emailed some pictures to you. If it is just a case of replacing these than I am confident I can do the job. So I can get the Transistors in advance can you identify them for me? Also are these normally the ones that burn from faulty RC valve adjustment? If not is it possible to tell what caused the problem to start with. Is there anything else I should know with regards to changing the Transistors before I start?