Bike running rich, jets, exhaust?

My 88 XR600R starts and runs GREAT but the supertrapp exhaust leaves a black mark on my rear fender everytime I ride it. I'm riding 55-60 mph 10 miles to work each way with no stumbles, bogs or flat spots. What could be the culprit? Do I need to change jets? OR is it the exhaust? Any help would be great. Thanks.

probably a tad to rich.

probably a tad to rich.

I got that figured out… already. Should I mess with the air fuel mixture screw or jetting? OR just leave it alone since it's running well?

all the super trapp's I have had have done that. hows your plug look?

all the super trapp's I have had have done that. hows your plug look?

The plug looks fine. I'm thinking MOST silencers tips face down so you never really notice any sooting IF you had some, cause it's in the wind........ Maybe it's normal with supertrapp's on thumpers?

It's normal for the black soot on the rear fender with the ST muffler, I wouldn't mess with it.

It's normal for the black soot on the rear fender with the ST muffler, I wouldn't mess with it.

Agree. I have had three XRs with Supertrapps, all three bikes jetted correctly, they all left soot stains on the fenders.

Agree. I have had three XRs with Supertrapps, all three bikes jetted correctly, they all left soot stains on the fenders.

OK then, THANKS for the validation guys, I'll be content with wiping off the soot and enjoying the ride:banana: If it's not broke don't fix it

s2_56.jpg

Under 4" Disc Series, part# 4AM2120 may help you if that is the type of muffler you have.

I have one for a bike of mine with a Supertrapp. I haven't installed it yet, but after I do and run it for a while, if you want to know how well or if it works as intended let me know. It will likely be a few weeks before I can say for certain.

s2_56.jpg

Under 4" Disc Series, part# 4AM2120 may help you if that is the type of muffler you have.

I have one for a bike of mine with a Supertrapp. I haven't installed it yet, but after I do and run it for a while, if you want to know how well or if it works as intended let me know. It will likely be a few weeks before I can say for certain.

GREAT find. I just put one on order! I needed to use my newbie discount on something pretty soon anyway!! THANKS:banana:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now