Yamaha TRX850 Enthusiasts Forum

took the trx out for her first proper ride yesterday and whilst giving it some it wouldnt rev cleanly through about 7k. it would get through it if i held it but obviously power was low.

any ideas?

uk or import bike?

its an import the clock is a kph clock but reads in mph. it does it in every gear. ive had about 120ish showing on the clock but i would say it would pull more if i had the road to do it on.

how has it been de-restricted? I seem to recall that some methods are better than others. Sounds like you may have had the clocks changed which "could" be the problem.

Slow Codger used a magic box of some kind that works.....he'll be along later to let you know, I'm sure.

im not to sure how its been de-restricted, the previous owner says it was done by someone else. the odometer aparently reads on mph and although the clock numbers are kph where it says 100kph that is 100mph.

i can't see and clock converter on it. nore can i see any red box's. i may have to take the speedo apart to see if anythings been cut.

what are the different ways they get de-restricted?

pretty sure the change of clocks removes the restriction (there is a metal tab on the KPH speedos) and I don't think it is that anyway as kooki has said it will pull through 7k (just not cleanly).

I'm sure someone with more knowledge of the Japanese market bikes will put me straight, but if not restricted by other means I'd go with either:

- mixture is too rich (either overjetted or not getting enough air)
or
- something is affecting the spark.

Whip the plugs out and have a look - and then report back here

I had a ruff running problem mid-rev range which turned out to be the carbs needing balancing.

Wouldn't suggest this as the first fix to try as it's best done by a dealer so will cost money.

pretty sure the change of clocks removes the restriction

..I believe it does too, but I think Kooki is saying clocks are still the original KPH ones, just read in MPH. Therefore there must be a KPH/MPH converter on the speedo drive cable, either where it attaches to the wheel or where it attaches to the speedo??

check the condition of the emulsion tubes (aka needle jets)
you may find these are worn oval

it could be emulsion tubes but I'd expect them to cause problems lower down the rev range. at 7k I'd be looking more at main jets.

I thought there was a problem with the import CDI and non import clocks, but don't recall all the details.

right been out on a good ride today and it i nail it in first and second it revs right through to the redline but if i roll in on it stutters. nomatter how i open it up in third onwards it stutters. Managed to get it to pull in top to about 130 on the clock before the stutter came in.

trixy -- the clock is a kph one but like i said reads mph, it hasnt got an converter on the cable tho. Theres no problem about balancing the carbs as i work in a motorbike shop (parts counter not spanner shop but i know my way around a bike)

youngy -- ive read somewhere if you use a mph clock on a import cdi it puts a rev limiter in every gear? i may take the clock out at work tomoz and see if its been tampered with. (how its been made to read mph)

Phuk72 cant check the plugs till next sunday. i'll probs get a new airfilter and put it in aswell as im not sure when it was last changed. (ive heard tdm's run quite rich from the factory


i'll check the emultion tubes aswell sunday. im thinking it maybe more carbs problems. i'll check the carb diaphragms aswell just incase ones split. could be a good excuse for a set of fcr's

ooooo found this through a search

http://trx850.motomaniac.net/forum/view ... restrictor

just seems strange that i can get through to the redline in the low gears. if it is some sort of restrictor mabe its faulty as such.

btw has anyone got a uk and import speedo they could dig out?
need to ask a few questions.
tom

Martin I've Been out.
Mine was restricted in every gear, depended on the cans as to what it would red line at, 7,000 with originals on and about 6,500 with the race cans. It would only do 112.5 mph, then it cut out on one cylinder! It did (and still has) the original Kph clocks on, but I bought a de-restrictor off E-bay that fixed it. I did post on here re the little box, easy to fit (have to take the fairing off), and solved all my probs.

Dave E

If your going to trim the tab back on the speedo,
DONT REMOVE IT COMPLETELEY!
It wont run at all and you will have to throw the speedo in the bin.

Dave E

Dodgy sidestand kill switch? I know it sounds funny but I had a similar problem which turned out to be down to this....