I was wondering what pipe you are using and what pipes you have tried. I am using my gyrt slip-on. Raptor720 cleaned up my head pipe. I am in no real hurry to change, this 686 rips the way i have it set up now. Thanks

 

I'm running a full HMF system, used to run the stock headpipe with a R Series muffler. So what did you end up at on your jetting? I am currently running dynojet neddles and mikuni 165/170 jets at 3500ft alt. Harry wants me to put the stock neddles back in and run a 180/187.

On the runs that you used to pull second gear on when stock, what gear can you pull now with your 686.
I was expecting that sense I had twice the hp I should be able to pull twice the gearing. Stock 2nd, 686 4th, doesn't seem to hold true. Maybe I am expecting to much.

 

The HMF system is not that good. I did not like my system at all. Lost to much on top and didnt gain enough on bottom. Hopefully the CT is better.

 

Syko... explain about the HMF system. I have the full system and definately noticed more power last season. Compared to the guys I was running with I had gained power and speed but... Just took her out for a ride last week against a new "stock" 2002 Raptor and I got spanked! He got me from 1rst gear on up and had a couple MPH more on top!

I am stumped on this one.

 

When I had the HMF with filter and jetting I would pull out in front until about third gear against a stock raptor then he would pull up and past me and leave me by a few bikes. The pipe is good for low end for on a MX track but you lose too much top.

 

Sandraptor- I have dynojet needles and stock jets. Changed to stock needles and 180, 187.5 needle clip in the 4th, fuel/air 2 3/4. WHAT A DIFFERENCE. Change those needles or get larger dyno jet jets. I got it to run good on the combo, but you will find a Big improvent changing.