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Discussion Starter #1
I bought a this new back in 2001 and unfortunately it sat a lot during its first 10 years.
A few years ago, I got it out and it was missing a little, so I put in new gas, changed the plug and took the carb off to clean the jets. This is where the real problem started. I dropped the main jet during this process. I ordered a new jet and washer that goes under the jet from the local Polaris dealer. It called for a 145 jet. I put it all back together and then it would not accelerate right. Would bog about half throttle and would not run right and like many others, I take off the air box lid and it runs fine. I got frustrated and it sat for several more years but this time I drained all the gas out so it would not set in the carb and lines. Fast forward to the past couple weeks. I once again removed the carb, took it apart including the main jet, air mixture screw, emulsion tube, pilot jet, basically everything I could take apart and put it through my ultrasonic cleaner. Now the carb looks brand new, the float is turning off the gas like it should, I have ran carb cleaning wires through every whole I can find and put it back together....now same issue. It seems as it is running rich. I did read somewhere that depending on the engine, some took a 120 main jet.,.,.not I can not find that info anywhere.

So in short, does anyone know about this 120 jet size even though all the parts diagrams call for 145? I also have the diaphragm out and pulled the needle to see where the clip is set and it is in the 2nd from the top.

any advise?
 

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You might need the 120 main jet with the needle you have in it. The main jet needle size and style make a difference in the performance. I would check to see that the main jet needle is the right one for the main jet you have. Take it out and get it under a magnifier. There should be markings on the needle just below the grooves. According to the parts diagram it should be an J8-5F14 with the 145 Main Jet

Seems like a simple thing but it does make a big difference. One of my 325 machines did that same thing. I fiddled with pilot jets and main jets trying to get it right for a month before I finally found that the main jet needle was wrong for the engine. Fired up an idled without using the choke, but stumbled about half throttle.
 

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Discussion Starter #3
it says 5F14 on the needle and it is set 2nd slot from the top. This is the needle that came with the bike new. I never replaced that. Just the jet.
 

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With that marking, I would have to guess that the main jet needle is right for the 145 main jet. What does your spark plug look like? Does it scream rich at you?
 

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Ok, it was bugging me so I went out to the shop and got my manual. According to this Clymer manual you should have a Mikuni BST31 Carb.

Main Jet with the engine model number ending in 06 or 07 should be 145. Engine model number ending in 08 will be the 120 main jet.

Main Jet needle is the same difference Engine 06 or 07 will use a SF14-3 Main Jet needle and the 08 model number used a SF14-2

Pilot jet is just listed as 50
 

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Discussion Starter #6
That is the same info I saw somewhere. Where is the engine type listed.

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If it's still there, it would be a sticker on the recoil housing.
 

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Discussion Starter #9
The sticker is there. I just have to look at it again. I don't think it ended in any of those numbers. I did the VIN search and came up with this.


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OK, the model number listed refers to the machine model. You should be able to take the engine serial number to a dealer and they can find out the engine model number. Or call polaris with it.
 

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Might be worth it to try a 120 main jet. Your e-clip is in the second groove down from the top so if you move it to the next one down that raises the needle and lets more fuel in. 120 vs 145 should be a leaner main jet right? However that is a lot of change......
 

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Discussion Starter #15
Correct main jet. Did you see the numbers on the engine cover I posted? It doeant end in either of the numbers listed. It does have 080 and then more numbers. The needle came stock in 2nd from top which in what I read is where it should be for the 120 jet. Could be totally coincidence. How would I go about finding part number for the 120 jet?

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Since Polaris only lists the 145 jet, I would take that to a shop or dealership and tell them you need a 120 to match it. Most places have an assortment of main jets. All they should need is the make and model of the carb.
 

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Discussion Starter #17
Well I ordered an assortment. Of jets from Amazon since my local Polaris dealer does not carry jets. Got 16 sizes for around 9 shipped. Put in a 120 and it started right up idled and took full throttle going down the road on several passes. I have not had time to pull the plug to make sure it is not running lean but it's a start. Now to change the oils that have been sitting in her for a few years

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Glad you got it! And you need to find a different dealer or small shop! Simply silly that they don't carry any assortment of jets. They must not work on many machines then.
 
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