BRP Stock Exhaust Tip Drilling of Inner Pipe

I drilled out my stock exhaust tip but instead of going the full two inches, I just drilled out the inner pipe. My drilled tip outlet now measures 1 3/8". It was a little complicated to accomplish but I already have a Pro Circuit T4 which is too loud for dual sport riding and I didnt want the stock tip too loud also. Have any of you done this and have some jetting specs? We are still at sub freezing temps here for a few more days. I plan to try it this weekend as it is supposed to get up to about 50 degrees F.

I bought my bike used, and the exhaust was already drilled out. He completely gutted the tip, it is basically only a cover now. Sorry this may not be relavent, but how would the bike perform with my gutted stock cap versus a proper HRC tip?

Hi.. YES! I have done exactly the same mod to the tip as you have, by drilling the "inner" part only. It was a real pain, to remove the core that way, having to wiggle the fiberglass packing out. I also have the 40mm competition tip, as well as a full race series Big Gun exhaust system. I have tried it all, so I can say the following. If you drill the inner core out like you did, then jet the bike as follows for alt. less than 1000': Stock pilot jet, 165 main, and stock needle in 3rd position. Of course you must also be using the 40mm intake boot, and remove the airbox restictors, both the boot and the plate. The bike will be better in this configuration, but not even close to as powerful as if you get the 40mm competition exhaust tip and rejet with the competition needle (set at 3rd position), and 175 main jet. This is the point where the real power begins to show itself. However top end performance will still be flat. So, if you want, opt for a complete aftermarket exhaust system which includes both header pipes and straight through glass packed silencer. Rejet to 3rd or 4th needle position (depends on preference), and 175 main jet. Now the bike will have slightly less low end, but a monster mid-range which will continue to a blistering top end surge! Of course the only problem with this setup is the EXTREME noise output. I ran my Big Gun Race Series complete exhaust system only for a few months, then went back to the stock pipes with 40mm tip and 175 jet, just because the noise was overwhelming and the Big Gun pipes leaked, didn't fit right, and the noise was just TOO much.

Hope this helps.



Another Big Gun disgruntled customer! Some day I'll be able to afford the saws-all to cut my header off. :) Of course, it only took 1.5 hours with a rubber hammer to get it assembled. If I had to do it over again I'd probably ceramic coat the header and get the White Bros E-series exhaust.

Ah man, Foobar! I went through the same multiple hour swear session of trying to get that Big gun system installed!! What a piece of junk really! The power was great, but the thing just didn't fit right at all! I had to omit a bushing at the frame juncture mounting, and force, hammer the thing in place. Pretty poor I think and a waste of money. Surprisingly, it came off pretty easily. WITH A SAWS ALL!! I put the stock pipes back on, and guess what? They actually fit, and don't leak!


Thanks for the info. I'm going to try it with the intake restrictions in first. Your info will save me alot of testing. I'll start with the stock pilot, raise the needle to the third position and a 150 main. I just want it to run "better". All of the off-road riding here is tight woods and I have a CR250 set up for that. The BRP is for commuting, which I expect will be a hoot!

"I'm going to try it with the intake restrictions in first."

Waaa?? The best was to restrict the intake is with your right hand. Uncork it.

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