Jetting Help Please!!!!

hunter78

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Joined
Feb 22, 2007
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Age
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Location
North Dakota
I Installed A Set Of Bender Triple Pipes On A 2000 Mm 700. Whats The Safest Way To Tell If I Have The Jetting Correct? I Really Don't Want To Have A Melt Down. I'M NOT LOOKING FOR JETTING SIZES. JUST A WAY TO TELL IF I HAVE IT TO LEAN. Help.
 
Last edited:

Well if you think you got the right(or close)jets in just keep an eye on plug
color(cardboard brown)and piston wash(search if not sure on PW).

start out by doing some slow speed runs,reach over kill the motor pull plugs
and examine.

do the same for mid then topend.

you DO NOT want white plugs,and use old plugs also,to hard to read new plugs.

good luck!!!!
 
If someone could explain piston wash that might be helpful. I am under the impression that wash is a better indicator. I have not worked with it much becasue my sled is not piped but someone else should be able to explain it. I would be curious on this also.
 
This is from the link above. Thanks Turk.


Reading Piston Wash 101
Date: 2006-01-04


We've had a ton of questions about how to properly read the piston wash on a snowmobile. This will give you some good general info about how to read your piston wash to accurately determine if you sled is running rich or lean. This is all based off a flat top style piston and a domed style piston may vary from these photos. These are general guidelines and dont take every factor/condition into consideration so dont call up bitching if you take these guidelines as law!!

Pic of a Lean Piston
The first piston is Lean. You can see it is almost completely black across the top of the piston. This is from the superheated gasses being immediatley carbonized onto the crown of the piston. This piston obviously seized and has alumium along the outer edge of the piston crown. Note: this is bad, you dont want this!

Pic of a Rich Piston
The second piston is Rich. You can see there is a very large amount of clean piston showing from all the transfer port areas on top of the piston. This is from the cool overly rich air/fuel mixture washing the top of the piston clean. Note: this is when you sled runs like crap. Ideally, you should have about a fingernail size portion of clean piston around each transfer port as shown in the next picture.

Pic of a Normal Piston
The last piston is just about right. This has a small portion of cleaned off portion at each transer port. Its a little hard to see clearly in the photo but a fingernail size portion is about right. This piston looks great for drag racing or even trail riding. A little more wash would be even a little safer.
 


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