Yamaha TRX850 Enthusiasts Forum

went to the yam dealer today to see what price the carb bits are ,well new needles £20 each,, needle jet holder £13,, and the black plastic slide £90,, all plus vat !!! so i had a chat to the mechanic he said if your fitting new needle jets you should fit new needles, the jet holder is also dead it has small cracks in it and is very rough were the slide moves up and down, the slide is also very rough on its bearing surface the mechanic then told me this is probably the cause of the jerky on off throttle because both bearing surfaces are rough as you open the throttle the negative pressure tries to lift the diaphragm the slide gets stuck because of the rough surface as the negative pressure increases it jumps up and gives this jerky on off throttle so the advice is change the emulsion tube , needle ,and needle tube Holder, and polish the slide with T cut .......Phat are you listing,,,,, just rememberd i didnt include needle jets this is because i got them from factory pro they came today thats only four days from the states to my door and they were $60

Time for FCRs

There's at least one set currently on that trading site....might be worth a bid if Scamaha are charging large fortunes for small parts...

I would lube the slide with ACF50 myself

All those parts are available cheaper at Kedo.

sorted, although my needles aren't standard....

did you know you can also change the needle heights using the different slots at the top of the needle?

i polished the plastic slides last night, they were pretty rough and scored. just moving the slide by hand now feels a hell of a lot smoother. too cold to go out on the bike to test it.

fitted the carbs back on this morning after a total rebuild, emulsion tubes ,needles ,slide holder, polished the slide and set the float height at 14mm(it was on one side 12mm and the other 11mm so very very rich ) cleaned all the internals and refitted back on bike ,,,,,,,,, the difference is unbelievable ,its a lot smother it wheelies off the throttle in first, no more jerky on off power and it seems to handle better ,, not a cheap fix at £100 for all the bits but well worth it

just read that post, including your sig, made it sound funny!

i wish i'd done this years ago.....

i kid you not phat its a differant bike !!!

Everyone underestimates the effect fo getting stock stuff right.

You are far better off (and will even be quicker on a track) sorting out your fuelling and spending some time getting teh suspension sorted. Instead, people prefer the bling on an open pipe and some carbon bits

steve speed wrote:not a cheap fix at £100 for all the bits but well worth it

£100 is a cheap fix really. I mean it's not a lot of money as biking bits go. I guess it feels a lot for such physically small stuff.

I mean think about it, oil and filter will set you back £30 or more. And two hours labour in a main dealer would be £100 ish.

I also have to agree with Phuk. In standard form the TRX can be pretty good. There is a tendency for some to not like some characteristics on bikes that may be approaching 10 years old, and that have done a few miles. But still people seem to go for a complex fix when actually putting stuff back to standard in proper working order, can give excellent results.

The same is often true with many vehicles that have been around a bit.

damn right, just go to any track day and see how many old golf gti's can still run rings around the evo's and stuff.

i may grow to like my trx after all if it runs right

i have had some where in the region of 30 bikes and like my trx best i have just got a r1 front and will fit my fcr's as soon as front is sorted it is definatly a under rated piece of kit standard or tweeked [for not a lot of money] would recommened to anyone KEEP THE FAITH PHAT

now this was unexpected ,,, i changed my oil a couple of days ago , and before i did the tubes the oil in the motor would go black in about 20 miles ,,Ive now done 100 miles and the oil is still as new color i also did a compression test and got 177psi and 180psi on the other cylinder has anyone had the same results????

probably because it isn't overfuelling any more!

i bet i was getting bore wash mine was so bad before. the old oil used to stink, probably full of fuel.

PhatVR6 wrote:probably because it isn't overfuelling any more!

i bet i was getting bore wash mine was so bad before. the old oil used to stink, probably full of fuel.

this is why i did a compression test i thought the bores might be f**ked