Dynojet to Mikuni

[mike J]

Does anyone know what a Dynojet 138 translates to in a Mikuni jet? Thanks, Mike J

[RacingJake]

Here's a chart but doesn't go that low. I'd say it's close to 130.

http://www.vmaxoutlaw.com/tech/dyno-mikuni.htm

[mike J]

Jake how were you able to run 160 jets? Did you have pods or no air filter? That's a huge jump from where I'm at right now. What about needles? Mike J

[Mr. Jiggles]

Just for the fun of it I plugged his numbers into excel and looked at the percent differences between Mikuni and Dyno at each interval. While the differences weren't identical for each interval, they were pretty close with an average percent difference between mikuni and Dyno of 6.6667% with a standard deviation of 0.017%. You can convert between mikuni and dyno with this equation (assuming the relationship remains linear outside of the mikuni 140-190 interval):

Dyno = Mikuni + 0.066(Mikuni)

Anyway, back to work.......

Here's a chart but doesn't go that low. I'd say it's close to 130.

http://www.vmaxoutlaw.com/tech/dyno-mikuni.htm

[RacingJake]

It all depends on what your bike likes, swap jets, make runs, review timeslips and see what works with your engine combo. But you'll need a baseline to start with, that why I say start big first cause I'd rather chase a rich condition than a lean one at the track. Once you can make a full run at WOT and it doesn't miss a beat then the fun is just begining.

With the 34 cv carbs, drilled out slides, stock needles no adjustment on them, worn out K&N filters that are 20 years old and the V&H pro pipe. Anything below a Mikuni 140 isn't going to work for me.

With the 38 GSXR carbs I'm running now with stock needles, no adjustment on them either and I'm running 165's Mikuni's with no air filter at all.

My bike would lay down in 3rd gear right before the 1/8 line with anything smaller than 150's. Bike would run with 150's but you couldn't tell the differance between 150 or 160 except for the time slips and with the 160's you could read the differance. The 160's were faster.

I was changing jets and needles like crazy at the track with the dyno kit a few years ago until I found out the differance between DJ and Mikuni jets, now I just use Mikuni's. It solve my problem cause the DJ are just to small for a drag bike but for the street with a restricted exhaust and carbs they will work fine.

I know alot of Bandit 1200 rider's do the same tuning with 160's.

Plus I like test and tune too

[mark m]

With the 34 cv carbs, drilled out slides, stock needles no adjustment on them, worn out K&N filters that are 20 years old and the V&H pro pipe. Anything below a Mikuni 140 isn't going to work for me.

I have found the same results as Jake. I have pods and a Kerker 4-1 on my 1100E and I am currently at 142.5 mains. I think I could easily go to 145's, but it runs strong as it is and it is another $20 I can spend elsewhere... I live at 3400ft, which is quite a bit higher than Jake and he is running at the track while I am not. I am sure that I would need at least 145's if I were to start pulling track runs like he is.


Mark