Yamaha TRX850 Enthusiasts Forum

im old and not good with computers, so forgive me if these answers are hidden away somewhere. my trx has never gone over 5000 rpm in top gear, also the speedo has stoped working. your ideas please. willie.

Does it pull through the rev range in the other gears, does it hit the rev limiter?
The speedometer problem could well be simply a broken cable, the bike not revving out in top could be carburation, plugs or coils breaking down, something creating excessive drag is possible too but less likely.
Sounds like she needs a damn good check over.
Speedo cable check is simple, undo the cable`s threaded collar at the speedometer, pull the cable into view and then ask someone to spin the front wheel while you sit astride the bike with it on the sidestand and lean it to the left to lift the front wheel off the ground.

Could the 5k rpm in top be due to a restrictor if its an import (1995, early 1996 with kph speedo) model?

Wot Mince said re: speedo. Cables have a habit of taking in water which runs down inside the sleeve to the bottom/wheel end and rusts through the cable inside the sleeve.

Undo it at the top and bottom (with your fingers or plyers/grips and give it a check over.

I think you'll find the limiter on the speedo is set at 180k's so thats a tall gearing to be 5000rpm.. I'd be lookin down the barrell of air restriction or spark

thanks for the replies lads, the problem is only in top, she revs out in all other gears. mph speedo, 96 bike, if its a restricter how do i bypass it. thanks again willie.

check this post - if it is restricted then this is the way past it i think.

one of the lads might confirm that for you that it is the right method!

http://www.trx850.motomaniac.net/forum/ ... it=tps+mod

again is the bike a Japanese import?

Japanese bikes (4NX frame number) are restricted to 180km/h (which is around 112mph), so if you're bike has high gearing it might be that. I also think they're limited to 7000rpm, but I could be wrong. Have a look at the cdi (under the seat?), if it says '4NX' on it, that's the problem

The only way around the speed restriction is to find and fit a POSH or M-Max derestrictor that plugs in the loom behind the speedo or fit a UK-spec (4UN) cdi.

isn't there a way of dismantling the speedo and filing down a wheel put in place to indicate to the black box when reaching 180kph.

thanks again lads, ill have a look at the weekend.

If its an import it will have a black engine. Yes it is restricted to 112.5 mph, and 7000 revs, taking the speedo apart and filing the tab down is not for the faint hearted, and dont remove it completely! mine has a little red box at the back of the clocks I got off E-bay with the gearing I have it will top out at about 135!

Dave E