I lost speed (used to be about 56 now its about 45) when I changed my needle valve and jets on my 650 I am running 4th notch and 128, 132 Dyno jets. It is my experiaence in cars that you go up jet sizes when you lose top speed. But whtere are no needle jets in them what does the different notches do. It says to use the 5th notch and Nyroc has found that the 4th notch is better. Should I try going up a notch or should I try richening up my jets to a 130, 134 Thanks for any info.

 

So would moveing my needle out one mor notch help a whole lot or should I go up a jet size.

 

I noticed that you did not list what kind of pipe you have. If you have stock pipe, jetting was not the thing to do. On the other hand, the needle is for mid throtle only. The main jet is what is for top end or wide open throtle. If I can help any other way, just ask.

 

Dynojet says adjusting their needle only affects midrange mixture (even though the needle is responsible for off idle to midrange). You need to mess with the mains to affect top speed.

One guy around here that has done a lot of jetting claims that we are too rich on the mains, and should back them off (and bring the needle to a higher notch if the midrange is too lean).

I called dynojet and they think we may be too rich in the mains, if the top speed is down.

Sorry, monte, I have been too lazy to check this out myself. good luck.

 

No exhast yet still debating on it I am waiting on the intake from DiamondGRacing and will post as soon as I get that on and try it out hopefully more air will lean it out if I remember reading the post correctly about air flow leaning it out.

 

Then I would lean the main to get your speed back. Might want to wait on Muzzy pipe. It WILL be the BADDIST!

 

Doesn't the increase in air also lean it out?

 

in the for what it is worth dept..(typical disclaimer this has worked for me in my street bikes, I HAVE NOT TRIED it in the quad..YET..but I will )

when I jetted both bikes I noticed this..if I was running WOT & still sluggish at high rpms, then backed off the throttle & it would clean up it indicated to me that the mains were too big..

if I was running out of steam about 3/4 throttle, mains are too small, (about 1 size) I would try to put the bigger mains in, then work down, the bottom end you are leaving alone, right, so you know how that works..to much fuel will cause it to bog..I try to get the mains right first, then tune it with needle position, or shims, or pilot size..

now realize that this info comes from a street bike with 4 carbs that was torn down 10 times & changed, about 50 posts to sharp carb gurus, (TC arizona was one of them) to get it right.. I got lucky, & got it perfect on the wife's bike..

the midrange is adjusted with the clip position, & main jet , top end is main jet..a plug check will tell you a lot..I have run my street bikes at WOT & hit the kill switch to check the plugs to verify main jet size before..

if you bought a kit, you can call dynojet & pick their brains as well..

any time you take the carbs off, & change the jets, you need to synchronize the carbs before you start to tweak it, or diagnose what you need to do..

maybe this helps, there are others here that are real sharp on this, I just did what I needed to by help, others, & trial & error..when you get it right, it is a BIG GRIN that you can't wipe off your face when you twist the wick..

 

When you put a smaller main jet in, you will be increasing air!