need reccomendations re-jetting 650R for altitude

3 replies to this topic
  • jesusgatos

Posted January 28, 2007 - 08:20 PM


I just drove down to southern CA and picked-up this 650R on Friday. When I pulled it out of the garage today, it started pissing gas out of the overflow hose and I had a hell of a time starting it. It was still pouring out gas after I warmed it up and rode it for a few minutes, so I pulled the carb out and took it apart to see if it was gummed up. There was a little bit of junk in the float valve, so I'm thinking everything will be fine once I get it back together. But I would like to re-jet this thing for the altitude here in Bend while I have it apart. The elevation here is about 3700ft and I'd prefer to jet it for best performance around this altitude and lower. Thanks in advance for any helpful input.

Engine info:
Hot Cams - Stage 1
Pro Circuit T4 head pipes and silencer
DT1 air filter
PO told me it has an oversized intake boot on it?

Current jetting:
Main Jet: 175
Slow Jet: 65S
Jet Needle: B53E (C-clip is in the 3rd groove - middle of five grooves)
Pilot Screw: 1 1/2 turns out

  • xplore

Posted January 29, 2007 - 07:48 AM


You can look at jetting specs on-line. Just google the pig pen xr650. This will probably be what you are looking for. As for your overflow problem... More than likely you had something stuck in your needle and seat that your floats actuate. If you haven't already, clean both with carb cleaner and you shouldn't have any troubles.

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

Posted January 29, 2007 - 12:16 PM


Thanks. I've seen those jetting charts, but the +2 -1 stuff wasn't making a whole lot of sense. I don't know if I have the stock needle and that chart doesn't mention how cams affect jetting. My best guess is that I might be OK with the main jet and the needle settings, but I should change the slow jet from a 65S to a 68S. Does that sound about right? Maybe jump up to a 178 main jet?

It also looks like the recommended jetting for different termperatures varies a quite a bit. Right now it's only about 30-degrees here, but in the summer time it ranges from mid-80's to the low 100's. If I jet the bike for this cold weather, how well is it going to run in the summertime?

  • wickedsprint

Posted January 29, 2007 - 12:46 PM


The plus and minus symbols mean size of jets, like if it has a plus one, that means one size larger than what is otherwise recommended on the chart.

Related Content


Supercross Preview 2017 Part 1: Championship Contenders by Chris Cooksey

Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  186 replies

XR650L super moto wheels by greggkklee

Dirt Bike   Make / Model Specific   Honda   XR600/650
  • Hot  29 replies

DirttyPig 2005 Xr650l Prroject! by braapmebb1moretime

Dirt Bike   Make / Model Specific   Honda   XR600/650
  • 22 replies

Post Apocalypse, ThumperTalk style! by Justin Pearson

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

93 xr650l Restoration Project by Zigster

Dirt Bike   Make / Model Specific   Honda   XR600/650
  • 17 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.