Removal of stock muffler tip vs drilling it with 2" hole saw?

11 replies to this topic
  • xrbrp

Posted February 18, 2004 - 04:30 PM


Will drilling the exhaust tip, instead of buying the tip, create any future problems riding in CA parks, if the noise is too loud? anybody had any noise issues :)

  • Dutch

Posted February 18, 2004 - 04:42 PM


Drilling the stock tip is a little more restrictive and quieter than the HRC tip.

  • big t

Posted February 18, 2004 - 06:46 PM


I don't think so. I drilled mine and it seems pretty quiet.

  • loufish

Posted February 18, 2004 - 08:30 PM


The good news, if you hole-saw the stock tip, it still leaves the spark arrester intact, no Ranger problems...

  • Roll_it_on

Posted February 18, 2004 - 08:51 PM


I drilled mine out and also purchased the HRC tip. I just keep the drilled out stocker with me in the tool kit just in case I run into any problems sounds wise. The drilled out unit is definately quieter however I do lose some punch with it over the HRC that I normally run. So far no sound problems. I have had rangers stick the wire into the end to make sure it is not straight through and does have a spark arrestor but nothing has been said about sound levels.

  • BrianVT

Posted February 19, 2004 - 05:10 AM


Is the flow close enough that rejetting isn't necessary when switching between the two ?

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  • slowxr

Posted February 19, 2004 - 08:20 AM


I've got the 2inch drilled out tip and did a sound check at Gorman. It pasted at 95dbs.

  • TimBrp

Posted February 19, 2004 - 08:51 AM


Is the flow close enough that rejetting isn't necessary ?

That's what I was pondering to Brian.

  • Roll_it_on

Posted February 19, 2004 - 03:56 PM


I have found that there is enough of a difference that for it to run spot on a smaller main is in order. Due to my eleveation with the HRC tip it runs right on with the 175 main. If I use the drilled stocker a 172 works better. I figured however if I ran into a situation where I needed to tone it down for a ride I could get away with it being a little on the rich side.

  • TimBrp

Posted February 20, 2004 - 06:40 AM


I looked into this further and on the Pig Pen site they have a jetting chart made up by some BRP GURU on the yahoo group. It states to use 1 size smaller on the main for the drilled vs HRC tip. I'm thinking I'm gonna buy an HRC tip and see if there is a difference. I'll post my findings. I hate to spend 140 bucks on it but it may be worth it, who knows.

  • qadsan

Posted February 20, 2004 - 09:59 AM


they have a jetting chart made up by some BRP GURU on the yahoo group

Now I'm :). I did that jetting chart on Eric's web site based on various mathmatics combined with experience and surverys from other BRP riders in hopes it would help people find a starting point to work from so they may get to their baseline quicker. It's by no means perfect, but it should help out considerbly if a person has no idea where to start from.

hate to spend 140 bucks on it

You don't have to spend $140 for it. You can buy it for $108 from Service Honda at and the part number is 18317-MBN-640. Also check eBay because I've seen them sell for as little as $25, but they usually go for around $50 to $80. There's a bit of difference between the two in terms of performance, but it's not earth shattering.

If you have access to the Yahoo XR650R group, then click on this link to see a represenative picture of the difference. Notice how the HRC tip fits deeper into the cannister to get some extra flow.


  • jws

Posted February 20, 2004 - 06:05 PM



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