can anyone tell me the easist way to take out the rc valve
from a 1999 nsr 125 please?
have been told could be the reason its not pulling properly at
higher revs.told that they gum up and eventually stick....
having had a look it seems dropping engine is the only way!!!!!!!!!!!!!!!
unless you know better,or know to try other things first.
thanks
Never worked on one, but I would be extremely surprised if the RC Valve assembly doesn't pull out with the motor en-situ.
It's a routine maintenance part on a (no offence) cheap learner bike... your average 125 rider isn't necessarily going to be able to afford to have a shop remove the motor just for RC Valve cleaning, and I expect many wouldn't have the tools or inclination to do it themselves either.
Again, my own assumption here, but I imagine it is very similar to the 150 (300) and 250. Look up the relevant page in the Online Parts Manual and you will see a diagram of the 250 components (the 150/300 is similar) and you will see that on those motors the assembly is held in by not much more than the oil seal! The E-clip DOES NOT retain the shaft in the cylinder - it just stops it sliding past the oil seal.
I have some scans of the 125 parts manual here somewhere. I will try to find them and that should give you an idea of what you are up against. I wouldn't expect it to be more than a 30 minute job on a single cylinder. _________________ Andy.
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The setup is very similar to the 250; the back of the 125 pulley housing does the same job as the steel backplate on the 250. The backplate holds the oil seal in place, the E-clip pulls up lightly against the oil seal and stop the shaft from pulling out. Once the backplate is off, the shaft is (relatively) free to slide out. The amount of carbon deposit on the shaft/Valves will determine just how hard it is to get the shaft out.
I imagine the retaining nut (part 13) is left-hand (reverse) thread, so take care when removing it... many a 250 owner has broken an RC Valve shaft by inadvertantly tightening the nut when they think they are loosening it! _________________ Andy.
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The later models of the nsr dont make as much power from my experience and when restricted 15hp and deristricted only 24ish hp if they dont pull well up top so probly needs de restricting.
If u can find a alcast uk model or earlier still as they produce more power de-restricted.
On my nsr125 i dismantled the control for the valve removing all the electrics and cables and locked it in the open position, then i removed the restrictor plate from the intake and drilled the exhaust washer out.
With a few diffrerent carb changes, some material off the cylinder base, bigger jets and advancing the timing slightly i had a very quick bike that wasnt fantastic going slow ran and ran on avgas. (obviously not alot more work than described but basicaly what i did)
I would remove the restriction on you bike from the inlet manifold and/or the exhaust. if there are none or if **** still having problems then id swap the ignition control from a uk alcast model.
The rc valve is as andy said and is worth cleaning if u have the time and can be done with the engine in the frame.
Power loss could also be due to worn piston rings!! _________________ Honda nc23 CBR400 AERO 1986, 1990 honda NC23 Tri-Arm, 1987VFR400 NC24 Rothmans Rep, NSR250 MC16 1987, CL250s 1983. Moto guzzi zigolo 110cc 1958. Fantic 50cc 1972. Suzuki Cobra Race bike 500cc 2t 1975 , GP125 1975. Triumph T110 1954. BSA Thunderbird 1955. Ariel VB 600 1952, 1990 MuZ 125 etz.
Thanks for info lads.its my sons bike and when ok did nearly a ton (on clock).but to me the frame is in the way........
will try and squeeze me hands in and give it a go.
And thanks for blow up diagram and the tip about left hand thread
cheers
Might be stating the bleedin obvious here, but you do of course have to remove the exhaust to extract the two halves of the power valve! _________________ MC21SP Plaything
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