this 95 spi has a rossier pipe and k&n filter and a single silver mikuni carb which i believe is stock. in the manual for a stock spi it says 147.5 main jet 65 pilot, low speed screw at 1 1/4 turns, and high speed at 0. what is in the now is a 107.5 main 65 pilot and both high and low speed screws were at 2 3/4 turns out. the comprssion is 140 psi in each cylinder and the ski bogs down and won't plain out. this ski seems to be jetted way wrong to me what would be a good starting point for this ski????
Piped 95 SPI Need Help Jetting
- Thread starter xprider02
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stickshift69
New Member
Take a look at the plugs to start with. I would start with Getting it to idle, then low speed adjuster, then pop off, then mains. It does sound like your mains are way too small. Verify that that is the oem carb then play with the low speed and go 2 sizes bigger then stock on the mains to start with. Keep an eye on the plugs.
ZeroTolerance
New Member
Are you sure its a 107.5??? That can't be good if so. I'd put a 152.5 main jet in it.
This should be CLOSE to the exact setup for your application:
Main Jet : 152.5
Pilot Jet : 75
High speed screw : 0 turns out from closed
Low speed screw : 2 turns out from closed
Needle & Seat : 2.3
Spring : Stock
*Note: This setup is for a Factory Pipe but should be somewhat similar
The color of your spark plugs will tell you if its running too lean or rich. Also the red portion of your pop-offs should be flush with the black outer rim. You just have to play with the jetting a bit to get it right. Patience is the key and your going to need a lot of it. Just be lucky you only have a single carb instead of duals. Im running the PPG Level 1 and my carbs use a 170 and 160 main jet.
Run the ski too lean and your going to be looking at replacing the engine
. Its always better to run rich than lean
This should be CLOSE to the exact setup for your application:
Main Jet : 152.5
Pilot Jet : 75
High speed screw : 0 turns out from closed
Low speed screw : 2 turns out from closed
Needle & Seat : 2.3
Spring : Stock
*Note: This setup is for a Factory Pipe but should be somewhat similar
The color of your spark plugs will tell you if its running too lean or rich. Also the red portion of your pop-offs should be flush with the black outer rim. You just have to play with the jetting a bit to get it right. Patience is the key and your going to need a lot of it. Just be lucky you only have a single carb instead of duals. Im running the PPG Level 1 and my carbs use a 170 and 160 main jet.
Run the ski too lean and your going to be looking at replacing the engine
. Its always better to run rich than lean
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thanks for the much needed replys the carb is a hi-performance mikuni 38mm it is silver and has 1 high and one low speed adjustment. The stock carb is a 38mm also so whats the difference in the high performance one that is on this ski and the stock one? will I have to go with total different jetting then stated above?
ZeroTolerance
New Member
Use the specs I listed for your current setup! Then run for a few minutes and check spark plugs for their color
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