make sure your not too big on the mainjet. that will kill your top end power too along with those tires. most people jet too big so they run a little rich. this helps with cooling but robs power.

 

My 6th gear used to suck also but as mentioned b4 a port and polish will correct that problem quick status! I currently have 13/36 with 18'' tires and 6th pulls just as hard as 1-5th.

 

Just for the record, the 86/87 SIXTH gear (mabey 5th too) was diffrent from the 88/89.The gear ratio was slightly diffrent. Thats why the older R's had more trouble pullin the last 2 gears than the 88/89 did.

 

Check out this link to a gearing - ratio chart, it should help u see how much of a change u will be making

http://www.sidewindersprockets.com/images/ratioa.gif

 

Thanks for the help I getting it ported and polished rite now. So I'll see how it prefrom after that

 

That's right. 1st thru 4th is the same on all the 86-89 bikes. The 88-89 bikes changed 5th & 6th gear to a lower gear ratio. It's easier to pull 5th & 6th on a 88-89. When you hit 6th gear on the 86 with stock gearing, It almost feels like overdrive. I know a lot of people who have had ESR change there 86-87 bikes trannies with the 88-89 5th & 6th gear. My 86 with just pipe, fresh motor & Sand skate 2's had to have 12/40 gearing to pull 6th gear in the sand on a long straight.