The more info I try to absorb on jetting the more confused I get. Do I re-jet or not?
I live and ride at 6400 feet. I've modified my intake and installed a UNI filter. This helped bottom end and midrange, no noticeable effect on top end.
I keep doing plug reads and ever since I opened up the intake the insulators are about a half shade lighter than the background area where the profile, email, edit, thumbs-up icons are on the message window. There is no carbon of any type on the electrode or the metal area below the threads, just a nice grayish blue color. The inside of my exhaust pipe is dark but there is no soot/carbon that will wipe off on your finger. The quad runs fine. It doesn't bog, has no flat spots, and doesn't do anything but burble a little on deacceleration. These three indicators tell me that my jetting should probably be left alone. Still I want it to be faster! I've gotten quite used to the factory power now and I want MORE!!!!! At least gain back the 4.5-5 horsepower that I lose at this altitude. Jetting ain't gonna get that back. It needs more air! Lately it's been hot (97) with single digit humidity and although it doesn't run bad it sure is doggy compared to 50 degree days.

 

If it were mine, please everone notice that I said MINE, I would install a Dynojet kit & a pipe.

 

More! More! More! Wolley, the dynojet will make the 650 much more reponsive on bottom and mid, but I think it will kill the top speed. I am still investigating why my top speed is lower. Haven't had time to do much. I do know that my 650 runs better than new everywhere except over 59 (it feels lean up there).

I think my exhaust mod added some upper RPM power too, because my 650 gets to 59 a lot faster now (but fizzles and takes forever to get to 63 if it is lucky). Diameter corrected (26" vs 24.3&quot, I get 66mph on a good day.

A pipe, like 2fat said will add lots of umph. Get the best one, don't go for least bux if you are really concerned about power.

Be patient for the cdi from DiamondG, and/or get a couple of CAMS.

Fourstroke tech will be making some kind of big bore kit for us too.

Yeah, do like 2fat4moto said, pipe and dynojet. By the time you get done with it, we will have worked out all the top speed issues.

 

Funds may be an issue! I recently just discovered that at 42 years old my 41 year old wife and I are expecting our first cracker muncher. Talk about a major shock! Must have been the new quads [img]i/expressions/face-icon-small-happy.gif[/img].
I cut and pasted the following from a post I made over at the Nation.

"I just re-jetted yesterday and for me it was a nightmare. I have the worst luck with phillips screws! I know this and I will not buy nor use a Craftsman phillips screwdriver, they are the worst ones made! The front carb, lower right hand bowl screw could not be acessed with any tool I had beacause of the cam chain tensioner. I ended up having to remove the tensioner to get to it. That wasn't the only problem. The bottom right hand screw on the rear carb would not come out and as carefull as I tried to be I ended up stripping the head. They make these factory screws out of the softest metal they can get away with. This meant I had to actually remove the carbs so that I could get a drill motor to the offending screw. If you're carefull the carbs can be removed from the intake boots and rotated around where you can work on them without removing throttle, choke cables, or the coolant lines. Once I got them where I could work on them and got the stripped screw out I discovered why it was so tight. It had been cross threaded from the factory. Had to got to town and buy a 4mm X.7 tap to clean it up. I also bought allen head screws to replace the phillips headed S.O.B.s with.
Now I should be able to remove the carb bowls without using 3 different length phillips screw drivers and the associated risk of stripping a screw head.
Re-jetting was the easy part. I didn't buy a jet kit so I didn't have to go into the upper half of the carbs. Moved the front 138 to the rear and put a 132 in the front. This is what Kawasaki recommends for my altitude. Only made a slight difference on the low and midrange, with throttle wide open, but it did give about 5mph on the top end. Tried a plug read but the plug color didn't change a bit. I'm thinking that I need to install a new set and try a color read again.

Couple of tips: Replace the factory screws with allen or torx headed ones!
If you do remove the carbs and leave them attached by the cables and coolant lines, duct tape over the intake boots so that you dont drop something in while you're working on the carbs.

Jets from Kawasaki are 6.50 each."

I definately picked up high end horsepower with leaner jetting. I should be a lot leaner now. Dropped six sizes in the front and seven in the rear. Still need more air! More in, More out. Got the in part covered mostly now I need to work on a pipe. Which brings on a lot more questions. Who do you believe about the horsepower claims? Is the biggest one.

 

Woole, Thanks for the info. Have'nt jetted mine yet because the funds thing. Just got married. I am a believer in Dynojet & will be using them when I jet. Also, I am waiting & hopeing that Muzzys will make a pipe. They have them for several quads, so I am sure that they will make one for our bikes. I also will be using the Diamond G intake with a Twin-Air filter. This is the combo I am going to go with unless Muzzy does not make a pipe. Then I will probably go with a Pro-Circuit.

 

I asked dynojet for main air jets to fix the top speed lean issue. They told me to ask Sudco, who does not stock smaller ones than 80 (stock size). they told me to call Keihin @ 262-860-6000. I am gonna call tomorrow.

 

Keep us posted on the issue.

 

I called Keihin, and they can't figure out what jet series it is, so they bounced me back to Sudco.

I am going to order a main air jet from the dealer, so I can show those yahoos a picture of it, and/or convince my dealer that they have some layin around.

I did find out that vulcans use a size 60, in a keihin carb. I bet they go in 5's or 10's. But, keihin says there are about 8 different types, each with their own size ranges, so I won't just go get a vulcan air jet just yet.

 

roc,
vulcans, some of the harleys have the kiehin carbs, sudco has stuff, but I only found i place on the net that has a good selection, but it is in australia[img]i/expressions/face-icon-small-shocked.gif[/img] the link is here otherwise maybe mike Penland can get you what you need. I still am not finding the time to do mine yet, I have a DJ kit, but looking at the taper of the needles is really strange, I know that this can be done fairly cheap with good results with stock jets, the only thing I've noticed about a keihin carb is parts availability is no where near what a mikuni is..
maybe the jetting page for the harleys (knightrider will give some leads..

 

Try 142 front and 145 rear.