Hi i have an '88 NC21 which will not exceed 60 mph!!! i try to open it up but the speed light comes up on the dash and the needle just wont move any further! the bike has been in this country since 1998 so i thought someone would have sorted it by now?? is it a rev limiter thing???

Any suggestions please!
It frustrating!

Thanks

Does it rev out in any gears before it stops at 60?

is it mis-firing at 60mph?

does it ride fine up until 60mph?




william

Are you sure it has not been restricted for a previous learner rider?

yes it revs out fine! it doesnt misfire it rides absolutely fine no problems it just reaches 60mph and just wont go any faster no matter how hard you pull back on the throttle also the speed light comes on!
Everything else is fine it just wont budge!
I would have thought even if it were restricted for a learner it would still hit 70 no probs!?

i would have thought even with a 33bhp restriction it would still be capable of 75+

what is the standard bhp from one of these?

my grandpa had a gs500 restricted to 33bhp and it would still do 80mph,in standard full power they were 58bhp.

because it is not mis-firing when you reach 60mph and rides normally this would lead you to believe it was power restricted.

it's maybe worth while taking the carbs off and checking to see if there is any restriction mods done.

is it standard size sprockets?


william

i would be putting my money on some sort of carb issue, wither or not its restrictor related or air filter related.

where abouts are you based and see if a local has a butchers at it

i am in plymouth i will have to get a garage to look cuz when it comes to carbs i've no idea! but why would the speed light come on? thats the strange bit so i didnt know if it was something to do with the cdi?

the speed light was a think that was installed as standard in jap. however i think its to do with the year, like pre 87 or something. i may be corrected tho.
i think also that the indication light is in no way connected to the CDI, i may also be corrected on this.
so pretty much a useless post.
can say i know any forum members for that area but there has to be some local bike cafes that someone could offer a free opinion at?

Does it rev out in neutral?

Sounds like your carbs need to be cleaned and set correctly.

Check for restrictors too!