650R european exhaust system ?'s

29 replies to this topic

Posted February 08, 2008 - 03:51 AM


Why have shitty low octane fuel in a nice beast as a 650R? :ride:

I use 98 octane for my XR's ,HC pistons or not ,I'm running a HRC piston for the moment in my 650. Better power,runs cooler etc .

For nearly 1.5 euro /litre in Belgium ,it better have to... :busted: :worthy:

  • zrt1

Posted February 08, 2008 - 04:39 AM


"I no about elivation and jetting, but elivation and fuel octane?"

When your leaning it up for altitude its because you have less air. Higher alt=lower comp=less oct. rating. I have not tried a lower octane. Id bump it up another point if I could. When its all said and done I'd bet that the 11:1 is about the same comp. or even slightly less than stock at sea level. 91 is as good as it gets other than race fuel or 100 low lead. Why run more octane than you have to. Run enough to cure detonation and thats all. Ive mixed 50/50 110 and 91 a few times and the bike actually runs slower. Remember I live at 5200 ft and up, Big power loss from sea level.

  • hondacrf150f1

Posted February 08, 2008 - 05:51 PM


im just wondering about what im gona have to do with a HP piston...one thing i though of is that all the gas stations today only have 1 pump. So if you click on 93 octane your still getting atleast a quart or 2 of 87 that was left in the pump. And with only filling up 2 gallons, that's a lot to give up.

Im not sure where else to look for higher octane fuel?
And wont you technically get better gas milege if your running on higher octane at the same consistant pace?

  • paul_scotti

Posted December 15, 2008 - 03:12 PM


Don't think it really matters with this bike. put one on that you like and got a good deal on.

I ran a big gun, white brothers megaphone and my current Jardine full system.

big gun was good but a crash took care of that
the mega was loud and excellent still have it as back up but too loud.
Jardine is great with good sound. for the money... worth it.

If you want the megaphone. I'll send it to you for shipping costs (and the box) it's in good shape and has been ceramic coated.

how much for the mega?

  • paul_scotti

Posted December 15, 2008 - 09:10 PM


the big gun seems pretty affordable. you had one..would you recommend it again? of those three you had...which, in your opinion is the best for top end power?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • XRandWRRider

Posted December 15, 2008 - 10:06 PM


... And wont you technically get better gas milege if your running on higher octane at the same consistant pace?

NO. Using a higher octane fuel than needed is a waste. Higher octane fuels simply resist detonation better, but contain no more energy than regular fuel. Extra power will come from higher compression ratios, but the higher compression can cause detonation without higher octane fuel. . . and that can be very bad.

  • Billahjack

Posted December 15, 2008 - 11:12 PM


I had a FMF Powercore4/powerbomb, stock header with tip mod, stock header with powercore4, stock header with yoshimura slip on, and a moriwaki.

The Moriwaki is by far the highest quality and uses heavier gage tubing. Nice pipe. I still need a bit of a compression bump from stock to make it sing though. The mesh on the spark arrestor is a bit flimsy but hasn't deteriorated yet.

I thought the FMF was a little cheap. Eventually, a piece of the baffle screen ejected through the spark arrestor screen. I call it the power slot.

The Yoshimura slipon was high quality and made decent power. I would say its a good buy, but the packing will wear out just as fast as the FMF pipes which seems kind of fast on the XRR. The Yosh got loud and barky when the packing started to go.

All aftermarket headers touch or come really close to the right radiator with the front cross-over pipe from the left side.

I sold the FMF but will never dump the stock header/can setup. Bike currently has the Moriwaki on it.

  • paul_scotti

Posted December 16, 2008 - 07:59 PM


I want a Moriwaki....but can't get one....:thumbsup:

  • paul_scotti

Posted December 17, 2008 - 05:13 PM


Here is what I am getting instead of the Moriwaki: Leo Vince (www.leovinceusa.com) Italian made and $300 cheaper than an Akrapovic.

  • sr71cbx

Posted December 17, 2008 - 05:34 PM


I use a stock can w/power tip and spark arrester screen with a Big Gun exhaust oversize header pipes from a full system on my XR-R......the Big Gun baffle flows well but is obnoxiously loud and attracts LEO attention too easy(I use it for street duty). It picked up more bottom end without a noticeable loss on top, and is considerably quieter.
Works for me!

Related Content


Fell Off Trailer by usafxr

Dirt Bike   Make / Model Specific   Honda   XR600/650
  • Hot  43 replies

Would a Young Scott Summers still be Competitive today on an XR600R? What would he ride to be competitive today? by Jayzonk

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  141 replies

ignitech programmable XR650L CDI by brianhare

Dirt Bike   Make / Model Specific   Honda   XR600/650
  • Hot  60 replies

Post Apocalypse, ThumperTalk style! by Justin Pearson

Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  35 replies

What was your path to Beta? by officialhopsof

Dirt Bike   Make / Model Specific   Beta
  • Hot  79 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.