New exhaust

I just installed a full big gun system, running a JD jet kit 50 pilot/ 165 main at sea level. Bike is a 2009 with 1600 miles on her. Bike cranked right up and ran great BUT... Seems like I have a very small leak at the head that I think I feel but the motor sounds like it's tapping?

Should I fiddle with this? I think it had a slight tap to start with maybe. Is it just engine noise.

Thanks in advance


what do you mean by tapping?

It sounds like a valve tapping at the top of the motor, It speeds up as the motor is revved. i did see my oil was slightly on the low side of the dipstick. The bike is new with only 1600 miles on it. It was tapping slightly with the stock muffler but was hard to hear and now its much louder with the big gun exhaust.

I need to adjust the header as There is a very very slight air leak coming where the pips meets the engine. Its not enough to even move a piece of paper just a slight feeling of air moving when I rev the motor.

My valve should not need to be adjusted at 1,600 miles?

I'd check your valves for sure, but it's likely nothing. It's pretty easy.

XR motors aren't particurally quiet motors.

Thanks, I feel about stupid after all the Bikes I have owned and this is my second 650l. I dont remember every hearing my first 650l tapping like this. I have had this 650l for almost 2 years, just dont ride it much and with 1,600 very easy miles on her I am very shocked that the valves even are a issue right now.

would a thicker weight oil help this out?

did you replace the copper gaskets that go between the exhaust and head, they crush down in some spots and stay thick in others to seal up the gap. if you are using the ones from your stock exhaust they might not seal in the right spots causing a leak that sounds like a tapping noise.

No I did not see any copper gaskets when I pulled off the stock muffler. I heard the Tapping before I did the muffler. I'm thinking the culprit is the exhaust valve. Just find it to hard to believe that with a brand new motor that has 1600 very easy miles would have a valve issue.

I do not remember copper gaskets on my 96 650l either. I'm gonna gave to investigate that.

Thanks for the replies, I knew this was the place to come!

Ordered new gaskets, gonna try that first.

Sometime the copper gaskets are hard to see once they flatten out....I just replaced my head pipe and had to dig them out with a small flathead....

50 pilot at sea level with the Big Gun seems a little lean?

I havent had a chance yet to see about the jetting, On my 96 650l I went with a 55 pilot and a 165 main with a FMF and it worked good but I didnt do the JD jet kit with the new needle and spring.

This time I left the 50 pilot with the 165 main and im gonna see what it does.

If is backfires on dec or gets hot Im gonna jump to a 55 pilot and leave the 165 main.

i still dont really understand what jets control what. I would love for somone to explain it in easy for dummies to understand.

Could it be that the 50 pilot at idle has it in a lean condtion that could be causing the valve to tap also?

Could it be that the 50 pilot at idle has it in a lean condtion that could be causing the valve to tap also?

Uneducated guess, possible.

I'll be the first to admit I am no mechanic. I don't pick up a wrench unless I have to and changing oil and a pipe and jets is about the limit of what I will attempt without help.

Thanks everyone for the help. It was the exhaust leak, changed out the gaskets and that did away with the tap. Ran good, still may have to go to a 55 pilot nit sure yet.

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