XR650R main jet size

[BigBore]

When I got my 650 home yesterday, I installed the following Power Up parts and mods:

-Intake manifold
-Carb needle (clip in middle position)
-Removed snorkel and restrictor plate in air box

Instead of getting the Power Up exhaust insert, I used a 2" hole saw and drilled out the baffle from the stock spark arrestor. Got that idea from here.

http://members.nbci.com/bhoth/nonepa.html

The Power Up kit came with a 175 main jet. So I put that in. Rode the bike, and it was running way rich. It would really lurch and blubber when you'd back off the throttle. So, I went down to a 165.....a little better, but still quite rich. So now I'm down a 160, and its still acting rich.

Any ideas? I wouldn't think I'd have to go any smaller than a 160. I thought maybe the air filter was over-oiled (there was oil running out of it), so I dabbed some of the excess off. Maybe I should just clean it and re-oil it correctly?

Thanks in advance.

 

[mtngoat]

On my buddy's XR, we removed the "smog pump" along with the rubber hoses and sealed the exhaust hole using an IMS part. This appears to be a common mod to most of the XRs I've seen and it eliminated the off-throttle bobble. White Bros sells the part too. You may be under-sizing the main to fix an unrelated problem. I don't recall the "post hop-up" recommended main jet size, but you may want to restore it.

 

[pw455]

Check out http://groups.yahoo.com/group/XR650R

You'll get some great responses on that forum for the xr650r. I'm thinking about getting one, so I've been checking the site out regularly. DRN is great for pretty much everything else.

Hope this helps,
Pete

 

[antrobus6]

i just got my xr650r and love it it really rips go ahead and get yours you wont be sorry

 

[Buckholz]

The power up exhaust is much more free-er flowing than the 2" hole cut out. At 7,000' I get proper plug readings with a 168 main in desert racing type conditions. At sea level I'm running a 175.

The screened area of the power up exhaust insert is about 6X the stocker.

My power up exhaust is not too loud.....

Check your right footpeg bolts regularly

Mark Buckholz
40+ A enduro racer and DS goober.

Join XR650Ryahoogroups for good info....