xr650l mods: all or nothing?

[JoeRC51]

55/158 is what I have in mine. Works well where I'm at here in central muchigan. I may go to a 58 pilot and 160 main though. I have to check my plug for color yet...

I also have an adjustable needle from dyno jet.

 

Your main jet is probably way too small with the DJ needle and your pilot too big. The DJ needle is made to work with a stock pilot and a large main. The DJ 160 and 165 from the kit are equivalent to Keihin 178 and 182 main jets.

[Srt8605]

Yw. I did Daves mods to mine. At first I was not sure about drilling the slide, but I went ahead and did it. It seemed to work well. I plan to swap out the stock carb eventually with a fcr keihin. That seems to be what many do for better throttle response. The stock one isn't too bad. It only hesitates once in the while.

[Srt8605]

Shoot, I got all mixed up here... That may be true. I have to pick up an 18mm socket to get my plug out. I figured it needed at least one size larger pilot due to the fact it will still periodically stumble when snapping the throttle wide open...

[JoeRC51]

With the DJ needle and a Keihin main , you're probably lean in the middle. Pilot has little effect above idle. 

[MI Mark]

Talked to XRs Only tech this morning.  Based on my mods: desmog, snorkel removed, Uni filter and FMF Q4, 750 ft amsl (no Dave's mods), he's suggesting 58/160 jetting and shim needle .020.  I ride high elevations out west for a couple weeks each year.  Wonder if maybe 55/158 would be better to handle both Michigan and CO/UT?  Not into messing with my carb that often!  Thoughts about that?

[lax30]

Talked to XRs Only tech this morning.  Based on my mods: desmog, snorkel removed, Uni filter and FMF Q4, 750 ft amsl (no Dave's mods), he's suggesting 58/160 jetting and shim needle .020.  I ride high elevations out west for a couple weeks each year.  Wonder if maybe 55/158 would be better to handle both Michigan and CO/UT?  Not into messing with my carb that often!  Thoughts about that?

im at 700ft in wv and I run a 58/160 shimmed at .02.  daves, desnorkel,dg slip on, uni. 

 

it runs great with those numbers but I have a hard to start when hot after sitting for about 20 mins sometimes. I say sometimes because I recently adjusted valves (none were tight, loose actually) and my uni was super dirty. It hasn't done it since.  maybe the filter was enough of a restriction to not start when hot. have been thinking of dropping back to a 55 pilot. my plug is a dark Mahogany color when at idle.

Edited April 25, 2016 by lax30

[MI Mark]

Thanks for feedback.  I spoke with local Honda service manager today.  He said go with XR's Only tech (58/160 shimmed 0.02).  But then I told him I almost hated to change anything because the bike is running/starting really well.  Better than ever actually (no popping on deceleration, no flat spots that I can determine).  His advice: don't change anything!  I thought for sure I needed to run richer, afraid of overheating the bike, etc.  He said by desmogging, it's going to run a little richer (less air recirculating), thus compensating for some of the extra air I'm pushing through it now.

 

Dang. He talked me out of doing anything (at least for now).  I'm gonna run it for a while and watch the plug.  

[Srt8605]

I think I may see if I can get a needle from the factory pro jet kit to replace the dj needle. My bike runs good now, but the dj needle did have a strange taper I just did not care for.

[JoeRC51]

Thanks for feedback.  I spoke with local Honda service manager today.  He said go with XR's Only tech (58/160 shimmed 0.02).  But then I told him I almost hated to change anything because the bike is running/starting really well.  Better than ever actually (no popping on deceleration, no flat spots that I can determine).  His advice: don't change anything!  I thought for sure I needed to run richer, afraid of overheating the bike, etc.  He said by desmogging, it's going to run a little richer (less air recirculating), thus compensating for some of the extra air I'm pushing through it now.

 

Dang. He talked me out of doing anything (at least for now).  I'm gonna run it for a while and watch the plug.  

 

Desmogging affects only what comes out of your exhaust and nothing more.

[bluffskier]

I want the XR's only non pumper Mikuni.

What's the best non oumper slide out there?

[MI Mark]

Well, the desmogging dumps a few pounds off if nothing else.  Local Honda guy said the smog stuff pulls in some extra air, thus reducing carbon parts per million to meet CA requirement. Removing it means less air intake (though minimal) according to him.  Whatever.  I'll run it with stock jets for a while and monitor the plug. I told him he'll pay for the work if I burn a hole in my piston!

[JoeRC51]

Low pressure in the exhaust draws air thru the smogtopus into the exhaust ports of the head. This is usually when the throttle is suddenly closed. No change in airflow thru the motor itself.