I took my carbs appart a couple of weeks ago because the bike was running a little rough, after cleaning out float bowls ect i put it all back together, with a little help from posts here, and fired it up, it ran far better, at low to medium revs, than it did before i cleaned everything out so i managed to get a warrant for it, now the problem is that before i took it appart once i took the bike past 9 grand it would just fly but now it just loses power, i tried to reset the powervalves as it says in the maintanance page but still no change, when i did try and reset the pwervalves after disconetcting the TPS and turning on the engine again the powervalve motor did not move that much, i only seemed to move about 2-3 mm. I was wondering if anyone had any ideas as the bike is running better than i have ever had it at bellow 9 grand but i want the top end because that is where the fun is. Any help would be greatly appreciated. My bike is a 1991 MC21 SE , wire splice de-restricted.
if the valves move that little, they are either stuck in the cylinders, cables are stuck, RC motors damaged or they are seriously misaligned, when you adjusted them.
Check it right away, as you risk burning out the PGM when the RC valves are stuck. _________________ Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom
Disconnect all four cables from the actuator pulleys, and then try the servo motor test. If you get full movement of the servo (i.e. from lo to hi and vise-versa) then it sounds like the RC Valves/spindles need a serious clean.
While the cables are disconnected, try turning the spindles by hand - they should move very freely. If not, then you WILL kill the PGM at some point.
It's also very important to check there is a very small amount of free play in the actuator cables once adjusted, as any tension on them can fry either or both the PGM and servo. _________________ Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
I dont have powervalve problems I dont think but my CDI (PGM in later models ) burnt out a few days ago. Fit another one that cost about 60 GBP and still have problems with my lower spark plug quickly fouling. Im wondering if the CDI burnout is related to this or if it was coincidental... Still dont know what the root cause is, but maybe my piston rings are buiggered after all that _________________ '87 MC16
hey you guys
its not nice to take over another guys thread, start your own. Ooops i forgot that I'm not the moderator but now I've said it. _________________ Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom
I've been watching this Poul, and it's a bit of a grey area! Kempo is involved in the location chit-chat, and if it ends up with him getting together with a couple other owners and getting his bike fixed, then that's a happy conclusion.
I would however prefer the location thread to have been started seperately myself too, that way the end solution to the RC Valve issue would be easier for future readers to relate to. _________________ Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
ahug030 wrote:I dont have powervalve problems I dont think but my CDI (PGM in later models ) burnt out a few days ago. Fit another one that cost about 60 GBP and still have problems with my lower spark plug quickly fouling. Im wondering if the CDI burnout is related to this or if it was coincidental... Still dont know what the root cause is, but maybe my piston rings are buggered after all that
The normal cause of a burned out PGM is the servo motor. Don't dismiss it unless you've checked all the possibilities - carbon build up, tight cables, siezed linkages etc.
Do a compression check to confirm buggered rings. You should get about 120psi.
Check the spade connectors for the coils. The tend to open out ever so slightly, and this causes tiny sparks, which lead to a carbon build up. Eventually the voltage drop accross the carbon means the spark is degraded and your plug fouls.
Have you checked the battery voltage too? NSR's like a well charged battery. _________________ MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
OK, this maybe a bit of a newbie question but i cant seem to find it in the maintainance guide or in previous posts, how do you clean out the powervalves?
Remove the cable end plate - remembering the nut is left hand thread (goes the 'wrong' way to undo).
Remove the mounting bracket.
Put the washer and nut back on the shaft, then lever the shaft out of the barrel - I use the prongs of a claw hammer, but others are more subtle!
The circlip you might be able to see doesn't hold the shaft in, it just secures the rubber bung.
You may have to pull bloody hard if the valves are badly coked up, but don't worry, there's nothing but crud holding them in. That'll teach you to clean them more often!
When the shaft is out, the two part valves should be removed through the exhaust port.
I clean them with a Scotchbrite nylon scrubby pad and the odd squirt of WD40.
Let us know how it goes... _________________ MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
More commonly known as an oil seal by us more "subtle" types!!
Is it? Never seen any oil behind it... _________________ MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball
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