Yamaha TRX850 Enthusiasts Forum

Hello, I've set my pilot jets at 2.5 turns out and the bike only runs properlywith the choke out one click. When I go to alter the pilot jets they seem to have altered themselves. I set them at 2 turns out and when I went to adjust them they were at 1/2 a turn out ! I set them at 3 turns out and I almost had it.TRX ran well, but the following day it only ran on one cylinder because one of the pilot jets had fallen out !! Any ideas why they are moving?

Thanks H.

Wear in the threads of the carb castings is the likely problem, try a little sliver of PTFE tape around the threads of the screws and try it again.
Alternatively you could use a dab of paint on the screw threads too, acts like a threadseal agent and as long as it`s used sparingly won`t get into the carb either.