Yamaha TRX850 Enthusiasts Forum

Hi to All,

Glad to be part of this forum,

I need help and advice

I Have recently bought myself a 1998 yamaha Trx 850, it has a set of Beowulf Exhausts on it.
So i've decided to buy a Dyno jet kit stage 1 for it which i have also recently fitted and a K&N air filter.
Now i've followed all the instructions provided, which was to fit the eClip 2nd from the top on the needles.
And to set the Aix mixture control screws 2.5 turns out, the bike seems to be running lean as there is smoke when i rev it,
i also checked the plugs which seem to be black which is a sure sign its running rich.
So i said id try and adjust the air mixture screws again little by little to see if i could sort the problem
and the Air mixture Control screws are set at 2 turns out and its still a little smokey.
I want to adjust them a little more but said i'd like to ask someone here that has experience incase i'm doing something wrong

First problem is the Kit, they are notoriously hard to tune and no better than the standard Yamaha parts.
Firstly, these are CV carbs, the air mixture screw is for idle and the first few hundred rev's, the needle takes over from there until it is at its max, from there on it all about the main jet.

Set the idle as described and leave it alone
move the needle up or down to suit for the mid to high revs
If it's still running rich, drop the main jet size and the repeat the last two steps.

If no luck refit the original parts and go down one size in the main jet or drop the needle one clip.

Thank you so much for the info Rod.s
I was also talking to to mate regards of the problem and he said the same as yourself,
i dropped the needle one clip.
its a massive difference in power, way quicker response, and the black smoke is gone.
Thanks again so much for all the helpful information.