I’ve just purchased a 22 mm mikuni for my predator 212 hemi. I have installed billet flywheel, billet rod +.020 length, .010” head gasket, exhaust upgrade, and then mikuni, my question is what jet comes in the mikuni, (purchased from gopowersports) and which jet will I need, I’m around 400ft above sea level, thank you.
Mikuni jetting help
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bob58o
SuckSqueezeBangBlow
I believe it is a 95 or 100. Maybe 105?
Call GoPowersports and ask them.
This is from Affordable Go Karts...
https://affordablegokarts.com/pages/carburetor-tuning
Armed with an assortment of jets and a free afternoon, we are confident you can tune your Mikuni for optimum performance. When we tuned our Mikuni we tried about ten different main jets, five pilot jets and every clip position on the needle jet. Our testing resulted in this final setup: 130 main jet, 12.5 pilot jet, needle clip in the center position and air screw two turns out (stock position). If you copy our setup you may or may not see great results. We recommend reading the tuning manual and trying different setups in order to achieve the biggest horsepower gains from this performance carburetor.
Tips: Our 22mm Mikunis come with a 95 or 100 main jet and 15 pilot jet. Bolt the carburetor up and run it for a couple laps with this setup. Pull the spark plug and take a reading. Chances are the plug will be white, indicating a lean condition. Start your tuning process by going to a larger main jet. Run a few more laps at a racing pace and check the plug again. Repeat this process until you get a good tannish brown plug reading. Remember to shut the engine down immediately when you pull to a stop, without letting the engine idle, to ensure you get an accurate plug reading.
After you find the desired main jet, you can move on to the other carburetor adjustments. Take note as to how your engine performs in all areas of the track. If there is a part of the power band you would like to tweak a little more, use the tuning manual to determine which jet controls that area of the power band. Experiment with different jet sizes until the desired performance is achieved.
---------- Post added at 08:24 PM ---------- Previous post was at 08:22 PM ----------
Here's from GPS...
VM 22 Carburetor. Low speed jet is .014, Hi speed jet is Part 95/.051. Mounting holes 48mm apart-- This is a Mikuni VM aftermarket carburetor made in China ( Good quality)
https://www.gopowersports.com/22mm-mikuni-carburetor-performance-kit/
0.051" is 1.30mm. Not sure what Part 95/.051 means?
Call GoPowersports and ask them.
This is from Affordable Go Karts...
https://affordablegokarts.com/pages/carburetor-tuning
Armed with an assortment of jets and a free afternoon, we are confident you can tune your Mikuni for optimum performance. When we tuned our Mikuni we tried about ten different main jets, five pilot jets and every clip position on the needle jet. Our testing resulted in this final setup: 130 main jet, 12.5 pilot jet, needle clip in the center position and air screw two turns out (stock position). If you copy our setup you may or may not see great results. We recommend reading the tuning manual and trying different setups in order to achieve the biggest horsepower gains from this performance carburetor.
Tips: Our 22mm Mikunis come with a 95 or 100 main jet and 15 pilot jet. Bolt the carburetor up and run it for a couple laps with this setup. Pull the spark plug and take a reading. Chances are the plug will be white, indicating a lean condition. Start your tuning process by going to a larger main jet. Run a few more laps at a racing pace and check the plug again. Repeat this process until you get a good tannish brown plug reading. Remember to shut the engine down immediately when you pull to a stop, without letting the engine idle, to ensure you get an accurate plug reading.
After you find the desired main jet, you can move on to the other carburetor adjustments. Take note as to how your engine performs in all areas of the track. If there is a part of the power band you would like to tweak a little more, use the tuning manual to determine which jet controls that area of the power band. Experiment with different jet sizes until the desired performance is achieved.
---------- Post added at 08:24 PM ---------- Previous post was at 08:22 PM ----------
Here's from GPS...
VM 22 Carburetor. Low speed jet is .014, Hi speed jet is Part 95/.051. Mounting holes 48mm apart-- This is a Mikuni VM aftermarket carburetor made in China ( Good quality)
https://www.gopowersports.com/22mm-mikuni-carburetor-performance-kit/
0.051" is 1.30mm. Not sure what Part 95/.051 means?
Thank you for the help, much appreciated!!
65ShelbyClone
Active member
When in doubt, pull the float bowl off and look at the jets. Genuine Mikuni jets should be marked.
I purchased a jet kit off amazon, 88-125, hoping that I could at least get it jetted so it was close to running well in a day, I received the jets and put a 105 in, it was still really lean, the idea was going up and down and the only way to keep it running was to twist the throttle a bit, or turn choke on, but it would idle really high, (I would have to have back wheel off the ground or it would take off) I need to know where to get some real mikuni jets, for a decent price, and I forgot to include I have a cl-2 cam, Thx
65ShelbyClone
Active member
What's your definition of a "decent" price?
Be prepared to spend $5-7 apiece for the genuine article.
What I would do is take one or two of the no-name jets that are least likely to get used and drill them out until the mixture is pretty good. Then find a Mikuni jet chart with the hole sizes and order a few jets near that size. Or just roll with the drilled jet. Up to you.
Be prepared to spend $5-7 apiece for the genuine article.
What I would do is take one or two of the no-name jets that are least likely to get used and drill them out until the mixture is pretty good. Then find a Mikuni jet chart with the hole sizes and order a few jets near that size. Or just roll with the drilled jet. Up to you.
what drill size would I need for each one? I would try 105 110 and 115 to start, thx for the help
bob58o
SuckSqueezeBangBlow
Mikuni hates us so they don't use orifice diameters for their jet sizes.
A Keihin jet that is 105 is 1.05mm diameter orifice. A mikuni jet that is 105 is different. They use flow rates or something. Google mikuni keihin jet size conversion chart to get a starting point.
http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm
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