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Mike Worshum

More on 06'XR650L jetting

3 posts in this topic

First I want to say thanks for a great site with good info. :thumbsup:

Information collected here gave me a starting basis for my newly aquired (last week) 650L. Like all jetting and mod procedures I started with removing the smog equipment and test rode it afterward. As expected it ran fine although still very anemic. Next was the carb jetting changes which I only used the slide spring from the Dyno Jet kit. I had read not to use the dyno jet needle unless the motor has cams and or headwork. From my past experience with Dyno Jet needles in a non modified street motor that made sense and used the old time favorite of the #8 S/S washer under the needle. The postings on this site recommends a 55 pilot and a 158 main. Since the bike comes with a 150 main and it's unbelievably lean, I chose a 160 main. This test was done with the stock exhaust and stock air box. Small steps right? reassemble and off for a test ride. The bike still needed a little choke (good thing) and it ran cleanly from the bottom to wide open. It would bring the front up in first no problem and pop it into second while still in the air. Forward progress is happening so I decided to remove the snorkel and change the main to a 162. It ran pretty much the same down low but seemed to pull a tad harder in the mid range on through to top wide open. The air screw was adjusted to 2-1/2 turns for both tests.

The pipe is on a big brown truck somewhere and I'll install the pipe first without a jetting change, but I'm suspecting a bump to a 165 main will be needed. This was all done at 300' above sea level, 65 degrees, with 20% humidity. Since I'll be leaving this bike at our mountain home in Wrightwood, I'm expecting to make a few changes to fine tune it up there at 6500 feet. Elevation and dryer air will be sure to effect these settings. I didn't install a fresh plug to get a plug reading :bonk: but seat of the pants feels like my new "L" model is going in the right direction.

However, since I used the Dyno Jet slide spring, I did NOT drill the bottom of the slide as some have mentioned...yet. I'd like to get more information on that procedure before doing so and is it commonly done while using a lighter slide spring? I would like to mention though, that by using a reamer instead of a standard twist drill, that the hole will have a much cleaner passage. A standard twist drill will leave flut marks in the passage, especially in aluminum.

So my new addition to the stable is still work in progress and thanks for the information to point me at the starting gate.

And why didn't my HTML sig not work :thumbsup:

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keep it simple ... if you still have the Dyna Jet kit ... use it exactly as the dirctions state ... disregard jet sizes you read about, as they are probably Keihin jets they are talking about, and they are a different numbering system ... use the DJ jet, needle, spring, and drill your slide ... if running an aftermarket exhaust , use the supllied largest jet ... mine runs great, my only complaint with the DynaJet is the price $$ .. I know, read the directions ? :thumbsup:

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I still say, don't use the DJ jets- especially if not using the DJ needle.

I have the DJ spring, and the drilled slide, and am wondering if that's opening my slide a little more for a given airflow as I'm running a 158 main with stock exhaust , and its a bit rich.

The larger holes open the slide FASTER, and the weaker spring opens it MORE for a given airflow (and maybe a little faster).

Dave

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