Motorcycle carb tuning

Did you set your needle clips in the position that the instructions told you? When you put the clips on, did you count from the top groove down, or bottom up? I believe that you need to go from the top down using the dynojet instructions.
How does it run at idle?
If you get past your 6000 RPM problem zone does it clear up?

This sounds like a lot of questions, but there are multiple circuits in the carb that must work together to give you best perfomance.

Here is the run down of which circuits affect which throttle settings:

Air (or fuel) screw 0 to 1/8 throttle
Pilot jet (small one next to the main jet) 0 to 1/4 throttle
Needle Position 1/4 to 3/4 throttle
Main Jet 2/3 to Full throttle

The length, diameter, and taper of the needle affect mostly the transitions between these circuits. Dynojet generally changes these parameters in order to avoid having to supply pilot jets with the kit.

If these are vacuum slide carbs (which I suspect they are) Dynojet also gives you new (lighter) springs to make the slides more responsive.

Based on the info you gave. It might be the main jet if the thing runs like garbage all the way through the throttle. If it runs ok at low throttle and ok at high throttle, you should look at you clip position (which is easier than changing main jets).

Post more info, and I will try to help out more.
Good Luck,
Ed

I am pretty sure I set the needle clip at the right position, one of the few illustrations in the kit was an arrow pointing to the correct slot.

It runs fine at idle, starts right up with little or no choke, then again this is summer time.

Above six grand it seems to non responsive. Below six it feels a bit more torqey, but not much. It could be dealt with, but the range up top is bad, I have a real hard time even getting into the flow of traffic on I-5 off a on ramp.

No new springs were given in my kit. I should check into that. Here is a link to the pdf of the illustrations for the kit.
I stuck in the 120s for the main jet. I might to verify that I stuck in the correct jets and I was loopy that night. According to your breakdown it most likely has to be the clip position or the main jets. I should check both.

If you go richer, and it falls on it's face at high speed, it is most likely a fuel supply to the carby problem. As you go richer, you use more fuel, and the inability to supply the extra fuel becomes critical.

Check needle and seat size, check fuel pump performance, check fuel filters etc.

Regards
pat

Well that could be a possibility I guess. I did take the tank off numerous times during the install and sediment in the tank could of moved and clogged my filter. Boy wouldnt I feel stupid.

Doesn't dynojet offer tech support- they certainly should for the prices they sell at!

Your problem sounds like one I recently had on my ZX10. After a BUNCH of work and swearing, I finally found that 1 of the carbs had a non-sealing vacuum diaphram. It wasn't torn or holed, just didn't quite seal right. After you remove your air cleaner, use your finger to lift the vac. slides. They should have a little resistance to being moved quickly, The one(s) that just fly up have the leaks. You can also listen to the sound of the air as it gets compressed a little and exits thru an air jet. The leaker won't make any air sound-just a sharp rap when the slide hits the top.

drwebb-

They do, but I was afraid of the advise from judging the poor instructions that came with the manual. Plus in the kit you have to fill out a lenthy questionaire about the condition and symptoms of the problem. I remember some of the requirments I couldnt do from the lack of tools or equipment such as mercury gages.

Metalguy-

I will check that this weekend for your suggestions. Its always a possibility, I too after a lengthy session of cussing, beating my head on the wall, the dogs and cats take off and I might of just missed it from blindness of frustration. Thanks for the tip.

As you accelerate to WOT (wide-open throttle), does your speed/RPM increase or drop a bit? If the latter, then your main jets are too small.

Have you checked the condition of your plugs? I understand the best way is to put new ones in, ride the bike at or near where you experience the problem (6000 RPM?), shut it down and coast/brake to a stop. Then pull the plugs and look at 'em. It's a pain, but it is a way to tell if you're rich or lean (sometimes).

Good luck!

. . . Steve

It doesnt drop in rpms when going to WOT, everything seems to take longer up that range as before around 6 it picked up rpms in a very quick manner. I changed the plugs when I did the other components along with syth. oil.

Check out the slides like Metalguy advised. I had one last week that the diaphram was not sealing properly on, and on a single cylinder it wouldn't get out of it's own way. With a 4 cylinder as you have, it wouldn't be as drastic of a difference, but would still drag the whole thing down. Seeing as you had to go into the diaphrams to change the damping spring, this is a distinct possibility.