assuming you have a stock carb. what are main, pilot needle jet settings? I aslo have a Vforce reed valve. I think mine's off a bit. BTW, mine's an 86.

 

According to FMF's jetting guide it should be the same as stock which is: main - 145, pilot - 42 at 0-2000 ft and 70 degrees. For me these sizes are perfect at 50 to 60 degrees. Warmer than that and it seems a little rich. I was actually going to try a 140 for 70 degrees. My elevation is around 1100 ft. I don't know that helps you at all but I will say what most everyone will probably say too. The only way to really get it tuned in is by reading your plug. Just use this as a place to start. You maybe even want to start a little higher on the main. Better to foul your plug than your motor.

 

I have an 86, stock carb, Boyesen reeds, and a K & N.
Stock main jet for an 86 is a .150.
You have a pipe/silencer combo and better airfilter, this means you will need to increase the main jet by at least 3 sizes. ...152, .155, .158. Aftermarket reeds will cause you to be a little rich. I have my airbox lid off, and the snorkle removed. I ran a .160 for elevations over 3000, and a .162 for lower. The .162 worked at Glamis for me.
Do a plug chop (do several!). Best way to find out if you got it dialed-in. Each machine is going to react a little differently, so you need to tune your's on it's own basis. If you don't know how to do a plug chop, post it and I'll tell you how. It involves a lot of time but is easy to do.

 

Stock main for 86 - 145

Stock main for 87 - 150

Stock main for 88-89 - 158


www.fmfracing.com

 

I just gotta clarify this.

The stock main for an 86 is a .150

The stock main for an 87 is a .152

Info from my Clymers manual and my Honda manual.