hi all
my son has a 125 nsr and recently started having problems ,
basically it wont rev above 7000 rpm and runs a bit lumpy at tickover.
obviosly checked the plug and was black suggesting running rich,cleaned carb was fairly clean any ideas please, as i havent!!!!!!!
thanks terry
i know these are fairly high tech so wondered if a black box or any other bit of witchcraft was responsible???
by the way its a 2000 model import unrestricted.

stick this in the nsr discusion forum.

what condition is the air filter in and how do you know its unrestricted? imports are restricted electronicaly depending on the country it was imported from. others are restricted by a plate in the inlet manifold between the rubber and the reeds its got a small hole in it restricting the flow of mixture. and others have a washer in the exhaust that you can drill out and make smooth.

does the valve work on the engine side ie move on the engine side when you rev high? the cables degrade on the 125's and can get stuck.

wha oil have you been putting in? u should use the best 2t injector oil yu can find and make suer no waters in it.

have you changed the spark plug? should be first thing you try?

does the choke fully disengage on the carb side? take the choke out and check its movment on the cable?
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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.

needs moving to nsr forums but.....

is it smoking a lot ? is the gearbox oil staying in the gearbox ? is the oil pump set right ? is the water level still up ? is there any splits in the intake boot ? is the air filter clean ? is the main jet blocked ?

alannsr250 wrote:stick this in the nsr discusion forum.

what condition is the air filter in and how do you know its unrestricted? imports are restricted electronicaly depending on the country it was imported from. others are restricted by a plate in the inlet manifold between the rubber and the reeds its got a small hole in it restricting the flow of mixture. and others have a washer in the exhaust that you can drill out and make smooth.

does the valve work on the engine side ie move on the engine side when you rev high? the cables degrade on the 125's and can get stuck.

wha oil have you been putting in? u should use the best 2t injector oil yu can find and make suer no waters in it.

have you changed the spark plug? should be first thing you try?

does the choke fully disengage on the carb side? take the choke out and check its movment on the cable?

first of all thanks for response
air filter cleaned and ok ,it,ll do nearly a ton on a good day so assume unrestricted,valve moves when revved high up,i,ve been usuing fully synthetic scooter oil!!!!!! (jaso fc/iso-l-egd/api tc+)
will change plug only cleaned it up but is fresh though.
will check choke aswell
is there an easy way to move this post to the other forum
thanks again

is the battery in good condition ?

fenton wrote:needs moving to nsr forums but.....

is it smoking a lot ? is the gearbox oil staying in the gearbox ? is the oil pump set right ? is the water level still up ? is there any splits in the intake boot ? is the air filter clean ? is the main jet blocked ?

its not smoking more than it did before(when running ok),the battery has lots of life in it,water level ok,filter was cleaned and main jet not blocked!!!!!!!!!
and thanks to whoever moved this for me sorry for a bit of muppetry....

How much movement in that piston, Might be stuck at those revs, thats alot of weight up their on that graph.
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HRC Is Getting Expensive

Its' like the AIR is crappy at Ground level.