rejetting for a new elevation

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

kozy

Well-Known Member
Joined
Aug 23, 2008
Messages
731
Reaction score
1
Location
Chandler, AZ
I moved from Northwest Indiana to Chandler, AZ a few weeks ago and am finally getting around to rejetting the bike for the elevation here...although technically back in Indiana it was never jetted correctly anyhow.

So....here's the setup:


  • Kerker 4-1 with 2.5" Comp baffle
  • Morley's Muscle Kit
  • I'm pretty sure I've got 152.5s in the carbs now.
  • I don't remember where my a/f screws are at.

The bike stinks like gas quite often. Did back in Indiana too.
Can anyone guide me in this search for proper jetting?
I went from about 900' elevation to just around 1200' here in AZ.

Got another question too....I was going to put a shim in each needle a while back and noticed that on each needle there appears to be a plastic "nub" that would prevent a washer from laying flat...call me crazy, but how do I shim each needle??? I'm cornfused.
 
I moved from Northwest Indiana to Chandler, AZ a few weeks ago and am finally getting around to rejetting the bike for the elevation here...although technically back in Indiana it was never jetted correctly anyhow.

So....here's the setup:


  • Kerker 4-1 with 2.5" Comp baffle
  • Morley's Muscle Kit
  • I'm pretty sure I've got 152.5s in the carbs now.
  • I don't remember where my a/f screws are at.
The bike stinks like gas quite often. Did back in Indiana too.
Can anyone guide me in this search for proper jetting?
I went from about 900' elevation to just around 1200' here in AZ.

Got another question too....I was going to put a shim in each needle a while back and noticed that on each needle there appears to be a plastic "nub" that would prevent a washer from laying flat...call me crazy, but how do I shim each needle??? I'm cornfused.


If you smell like gas you should drop at least one jet size. I would order 150s and some 147.5s at the same time so incase the 150s are still too big you have the next size down.
Get your jets straight before you start shimming needles. If the mains are rich then you needles are already rich. No need to shim them. If you do need to shim your needles the shim goes between the plastic "nub" and your E clip. This way it will lay flat and still pull the needle out of the jet block. But seriously get your mains right first, they effect the needles as well. Hope this helps
Cheers
 
can't agree with fargo more. you have my # too eric if ur in the middle and want to bounce something quick. i'm not expert but i've been in 'em quite a few times. did my needles probably 10 times this summer.
 
Back in Indiana I thought i had the mains just about right. I made the mistake of trusting a dealership to jet the bike originally, and the idiots screwed it up badly. They put something like a 165 main jet in it or something crazy.

I knocked it back down to the stock 152.5 and noticed a bit of a hesitation-ish around 4K-5K which is why I thought about shimming the needles.
But here at a higher elevation, I'm not sure if I even have the main jet right. I'm going to spend some time tinkering around with the mains this week hopefully. I'll try dropping a size and see what happens.
 
you have my # too eric if ur in the middle and want to bounce something quick. i'm not expert but i've been in 'em quite a few times. did my needles probably 10 times this summer.

And yeah, I did save it in my phone so if I ever need to, I'll give you a buzz.
 
My elevation is about 3500ft and my bike smells as well!!It runs really good but it stinks changing the jets sounds good.My bike is bone stock.
 
Make sure the float levels are correct!

Sean

Oh crap, that's right. I never split the rack and checked the float levels after the dealership had their hands on it. I should probably have done that a long time ago, eh?

I read up on the thread about setting the float levels and I think I'm losing it. Everyone talks about a circle that's cast into the carbs but I can't see it. Am I blind? Or just need new glasses?
 
About eraser sized and useful as a reference but get a scale or calipers to set them right. I debated making a few carb float measuring tools but just haven't finished them up.

Sean
 
I use a digital caliper I got from Harbor Freight for about $20.

Or do a wet level adjust....I used the little clear plastic tube that came with the Dyna Beads, made a tic mark 17mm back from one end,put the carb drain hose in the other end. Works perfectly.
 
Hey Kozy:

My bike is a similar setup to yours (I have the Morley kit and aftermarket pipes), and I'm also in AZ at an elevation similar to yours. When I bought the bike, it too would cease acceleration at around 90-100 mph. So, this is what I did:

1) Brought the needles down to the LEANEST position.

2) Left PAJ1 at 100

3) Changed PAJ2 to 175

4) Make sure float height was good. (Gotta remove carbs for dry method, which I did)

5) Changed main jets from 160 (too rich) to 155 (I made it LEANER)

6) Reinstalled carbs.

7) Synced carbs

8) Checked/tuned mixture screws

9) Synced carbs again.

I did this all myself. Now, the bike zings right up to 150 mph. Everyone's gonna have a different opinion on what to do...but this worked great for me.

I have 155 jets and 100 jets, but no 175s. Lemme know if you need assistance.

Elimx
 
Hey Kozy:

My bike is a similar setup to yours (I have the Morley kit and aftermarket pipes), and I'm also in AZ at an elevation similar to yours. When I bought the bike, it too would cease acceleration at around 90-100 mph. So, this is what I did:

1) Brought the needles down to the LEANEST position.

2) Left PAJ1 at 100

3) Changed PAJ2 to 175

4) Make sure float height was good. (Gotta remove carbs for dry method, which I did)

5) Changed main jets from 160 (too rich) to 155 (I made it LEANER)

6) Reinstalled carbs.

7) Synced carbs

8) Checked/tuned mixture screws

9) Synced carbs again.

I did this all myself. Now, the bike zings right up to 150 mph. Everyone's gonna have a different opinion on what to do...but this worked great for me.

I have 155 jets and 100 jets, but no 175s. Lemme know if you need assistance.

Elimx

Aaron, my bike has noooooo problems accellerating above 100. Not in the least...I test it out all the time just to make sure :biglaugh:

I went to an open parking lot today and re-configured my A/F screws. I've got them all set at 3.5 turns out. I tried them at 3 turns out, but my throttle response seemed to suffer until I turned them another half turn.

I got a job offer today, and I start on December 7th....so that leaves me 2 1/2 weeks to get the bike finished. That should be enough time, don't ya think? LOL
I might try to tear the carbs apart tomorrow. Or Monday. Hell I don't know.
I did the math to figure out what jet size I should have relative to elevation (found it in the "same ol jetting" thread. I never had seen that equation before. The math shows I should be at a 150 main. I think I might downgrade to that size and tinker. Luckily, I kept all of the jets that Sean sent me with his kit. Phew!
 
Well damn. I just checked my stash of Mikuni jets. I've got 5 different jet sizes with the smallest being the 152.5s. Everything else I have is larger. Gotta find me some 150's
 
i assume mr morley will be getting a call. hah.
 
:punk: Eric, congrats on the job! Now you have something to do during the day. Good luck with the carbs abd emmissions test here in Arizona. Have a nice Thanksgiving, Steve
 
i assume mr morley will be getting a call. hah.
Oh yeah you know it! Maybe I can barter with him....trade some larger jets for some smaller ones.....

:punk: Eric, congrats on the job! Now you have something to do during the day. Good luck with the carbs abd emmissions test here in Arizona. Have a nice Thanksgiving, Steve

Thanks Steve! You and your wife have a great Thanksgiving as well.
 
I'm at about 4300 ft here in Salt Lake City and just had my 06 tuned at SLC Motorsports, by Matt Spencer. She's running very strong, great throttle response, good A/F ratio throughout the throttle/RPM range and nice consistent power curve. The final settings with a DynoJet Stage VII, K&N filters, Marks 4/2 are:

Mains - 138
Pilots - 40
Needles - #4
A/F - 3 turns out

Steve
 

Latest posts

Back
Top