Yamaha TRX850 Enthusiasts Forum

Hi guys
Just wondering if anyone can help with this;

Symptom; cruising along at part throttle at about 3500 rpm, and engine hesitates/misses. If I open the throttle further it pulls out of it and accelerates ok. Problem only occurs at part throttle and at about 3000 to 3500 rpm or so.

I thought it might be the throttle position sensor but I've measured the resistances etc and they check out fine and the rev needle points at 4000 rpm when doing the diagnostic check so it seems to be fine.

Any ideas?

Search "emulsion tubes" and maybe get a Litetek viton seal kit.

I changed the emulsion tubes a few years back and havent done huge mileage. The problem is kind of intermittent too. Perhaps a bit worse when its warm??

You might want to check the small white plastic caps on the side of the carbs ,especially the right side card ,(as you would sit on the bike). They are prone to cracking with age.There Is a thread on here about this very problem but I couldn't find it.