Yamaha TRX850 Enthusiasts Forum

G'day guys. Been working on my new to me TRX the past week.

I bought a keyster rebuild kit to replace my worn emulsion tubes.

After doing the teardown and refit it was obvious that I wasn't the first one inside this carbie (bike only has 30k on the odo).

I have now had the carb back apart a dozen times because the bike is not running right. It has an aweful misfire / breaking up at 1/8 - 1/4 throttle.

Most recently I have noticed that there is no plastic washer beneath the needle (between needle clip and slide). Should there be a washer there (parts manual seems to suggest so?) and what thickness is it if someone could measure one for me.

Going to start experimenting tonite with various thickness shims tonite to see if I can come to any improvement.

Help of the collective would be much appreciated.

Thanks, Rob.

Check there is no crack or air leaking through the white plastic air cut out valve on the side of the carbie.

http://www.trx850.com/phpBB_forum/viewt ... 9&start=30

Thanks Brian. My post above was a little rushed as I was I between getting the carbie back iN to take it for a further test ride. The white plastic seems to be in decent condition.

I put a 2mm oring beneath the needle clip and it seems to have cured the problem.

As the needle is already on the richest clip position I could always go with a bigger spacer so as to end up with a larger range of adjustment.

It seems that the previous owners idea to cure the symptoms of worn emulsion tubes was to remove the plastic washer beneath the needle clip to lean it out.

Atleast it's running pretty good now. Will just be fine tuning from here I think.

Also of note, the little flat steel retainers that hold the main jet in place seem t be missing. The only thing holding the main jets in place is the friction of the oring on the jets themselves.

crigsta wrote:Thanks Brian. My post above was a little rushed as I was I between getting the carbie back iN to take it for a further test ride. The white plastic seems to be in decent condition.

I put a 2mm oring beneath the needle clip and it seems to have cured the problem.

As the needle is already on the richest clip position I could always go with a bigger spacer so as to end up with a larger range of adjustment.

It seems that the previous owners idea to cure the symptoms of worn emulsion tubes was to remove the plastic washer beneath the needle clip to lean it out.

Atleast it's running pretty good now. Will just be fine tuning from here I think.

Also of note, the little flat steel retainers that hold the main jet in place seem t be missing. The only thing holding the main jets in place is the friction of the oring on the jets themselves.

I have the remains of two carbs here, I'll check what's left, might be just what you need.