what dose re-jetting consist of? do you have to guess and check till you get the right jet. And how difficult is it to do?

 

Good instructions on another this site.http://www.advrider.com/forums/showt...107591&page=49

 

Read all about it (with great pics) right here.

 

I'll go ahead and answer it. The more expereinced guy can correct me where I'm wrong.

Jets are just small brass nozzles with a specifc orrifce size to restrict the flow of fuel as it is sucked into teh airstream. The assocaited needle acts as a needle valve to additonally restrict the flow of fuel out of the main jet. The other smaller jet associated mainly with idle speed and low RPM's doesn't need to be changed. It is adjusted by the mizture screw, and there is enough range of adjustment on that jet size.


I had never messed with carbs unitil this bike. I was a little afraid. I think all of those hoses going everywhere scared me. I was suprised that it's pretty easy, and luckily with a single cylinder machine, there no sychronizing involved and only 1 set of jets/needle to change.

My tip, when removing the tank, leave the petcock attached and unbolt it from the frame. And get a 8mm nut driver to remove all the 8mm bolts. I'm also going to replace all those annoying cheap clip type hose clamps with regular screw tight clamps. Lastly, getting the rubber ductwork re-attached just takes a little patience. You also have ot push the wire harness under the tank aside to get the carbs out.

It might be possible with a right angle screwdriver to get he float bowl off and rejet without removign the carbs... but I think it might jet be easier ot take it off the bike.

Any one else have an opinion???

 

It's possible to do the carb work by just loosening both the airbox and intake clamps and removing the throttle cables. You can then twist it left or right to access the needle on top or jets on the bottom. However, it's not much harder to just remove it and work on it at your bench.

 

Well, I got the 128 main jet, the Dynojet tapered needle on the 3rd clip and the mixture screw I left at 2-1/2 out. Put the carbs back on and she fired right up with the chock on, barely cranked any longer than normal. Nice deep subdued thump, thump, thump. It's pretty loud. On main street, 2 "ricers" pull up... and I could barely hear their loud exhausts... which led me to belive that I was just as loud or louder. But it sounds really great. I normally wear earplugs, so it should be just about right then. I heard tha it gets a little quieter after the packing breaks in a little.

Power wise, definitely stronger across to whole powerband. Definitely opened up the top end. It pulls pretty much equally hard to the limiter. Suprisingly, the bottom end also feels stronger and much smoother. IT will pull down at 2500-3500 if needed. The one issue I have is a lot of popping and a little bit of backfire when deaccelerating abruptly from over 7000RPM. At one point I even heard a couple nice ping from the muffler. My gut feeling is that it might be a little rich. And the needle is to blame. I think I should put it on the 2nd clip to lean it out a little. I also used the drill bit provided in the kit, which was even slightly larger than the 7/64ths I used before. When downshifting while deaccelerating, I can tell it's holding the throttle open a little more, which actually makes the downshifts really really smooth. The on/off throttle transition is much more defined... or rather there IS A ON/OFF transition, where before the only thing you felt was maybe a little drivetrain slop.

Overall this baby goes "Grrrr" and IMO now pulls harder than a stock DRZ400. After I put on the 45 rear sprocket to go with the 13T front I have now, 1st gear will be almost useless on the street. It is fun ripping through 4 gears getting up to 30 mph pulling away from a light.


Just a reminder:
- Crankcase breather mod
- Airbox snorkle replaced with a larger KX unit.
- air injection piping removed
- spark arrestor & quiet plug

Conditions tonight:
54F, 76%RH, 600 feet above sea level


So do you think it's a rich needle setting that's causing the popping and slight backfire on deacceleration from over 7000RPM?

Below are some pictures of the spark plug. Although the last 4 miles were mostly at 30mph in 5th or 6th gear.

 

Total I rode for about 35 minutes and covered 22 miles.

Plug picture #1

[IMG]local://upfiles/1299/FF5819664BDF452388DC08EC166B9137.jpg[/IMG]

 

Pic 2


[IMG]local://upfiles/1299/CFA48914A7D24332A8E1FE50E86B6824.jpg[/IMG]

 

lt doesnt look like its running rich from the pic of the plug, looks pretty good. it would be darker on the electrode like it is around edges if it was. is there any deposit build up on the electrode? this could indicate a lean condition. i noticed the klx pops under decell. when stock with stock pipe, you probably just can hear it a lot more now. my opinion. anybody else have any info??

 

I have a question about the Muzzy pipe. Now if im cheap and just want the slip-on version of this pipe will I need to re-jet the carb or can I just leave things the way they are??