drilling tip

Right about now I'd like to uncork and rejet by 650R. Not sure about dropping $100 on the HRC tip if it doesn't offer that much of a performance upgrade. I understand the HRC tip goes further back in the can and past the baffles more so than the stock tip does.

Would like to hear from those who have compared the 2 ways. I understand the stock tip drilled is a little quieter which is a bonus but if it still chokes off too much I don't want to use it.



I would just drill it if I were you. Mine was drilled when I bought a HRC tip from a guy on TT for $40. I can tell a difference but I wouldn't have paid $100+ for it. Drill it then look around to find a used one for sell later on when you have the money. :cry:

The stocker drilled out is quieter then the HRC however there is a big difference in performance in my opinion. The typical uncorked jetting (175 main) would be to rich for the drilled out tip. I stuck the drilled stocker into my bike just for the nuts of it one day and it ran like crap so out it came in a flash. Do check around since you can get them for alot less then 100+ bucks. They show up here and on EBAY all the time.

I did the uncorking on mine and drilled the stock tip, also removed the 1st baffle from the spark arrestor. That leaves the arrestor intact to do it's job. I've heard the HRC tip is a bit louder, but not an issue if you're not in a noise sensitive area. I am at 200 feet elevation and I used the 172 main jet - seems to be about right. You will like the way your pig starts and runs after you uncork. Hang on!

I would suggest getting the HRC tip. Baja Designs has them for $50. Yup 50 guys. I kicked myself for a week after getting one from Honda. Better flow, better sound.

Baja Designs has them for $50. Yup 50 guys.

Don't kick yourself too har because the $50 baffles is for the xr250. The xr400 baffle is $43 and the xr650r is $131. Look closely at their web page and you'll see how their prices breakout.

It used to be that saying "drilled tip" only meant one thing - the single 2" holesaw attack, which is #2 below. Now it can mean any one of the following (in order of increasing flow area):

1) Drill (well, grind weld) at 1 1/4" and removed 4" long insert

2) Drilled to 2" and removed 1 1/4" insert

3) Same as 2 but with stand off baffle snipped off

4) Same as 3 but with 1 to 1 1/4" hole through remaining baffle and stainless mesh bolted over this hole (to retain S.A. function)

The same list (in more detail) is on the PigPen XR650R FAQ. Note that you can go back to #3 from #4 by replacing the stainless mesh with a stainless disc, if you need to be a bit quieter.

I have no trouble believing that #1 to #3 will perform worse than the HRC tip. For all three of these, the annular flow region remains the bottleneck. But the total area for flow of #4 (through the new holeand around the remaining baffle) is quite large - I think larger than the area of the final output of the HRC tip. So I'd expect #4 to dyno up very similar to what the HRC tip gives (but I have no actual proof of this.)



Really, well thanks for clearing that up! I thought I was getting bent over by Honda. It appears I paid the "price". Anyhow, I totally prefer the HRC over the stock drilled. Think of it this way, if you go to a race and they check you for decibels, I think the HRC at an idle was 99 db. That's loud. You can always throw your stocker back in for tech spec.. :cry:

Right now I'm at #2 tip plus a home-made down-tip. It's real quiet (90db ?) but way less power than the Big Gun.

Does #3 actually improve flow ? I don't know how the exhaust gets by either one of those "stops".

Any guesses how much louder I'd be if I snipped to #3 ?

I'd hate to cut and not be able to pass easy for 96db.

I'm hoping for a happy median.

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