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OT: Polaris ATV Idle mixture screw????

15K views 4 replies 3 participants last post by  pontiac58 
#1 ·
I need some help. My 1995 Polaris Magnum 425 won't idle. It runs great as long as the throttle is engaged. I have adjusted the idle speed in and out without any luck. I have the factory service manual, but it is lacking in most areas. There is a idle(pilot) mixture screw used to tune the idle. I cannot find this screw. Based on the manual it appears to be at the front/bottom of the carb. If I am correct, you would have to use a very short shafted screwdriver to get to it because the carb is almost sitting on the block. This is a Mikuni 38 carb if that adds anything. Let me know if you have adjusted this before.

Thanks,
Tom
 
#2 ·
Tom it been awhile since i wrenched on a 425 but i kinda remember a problem with what you are talking about. I havent worked at the dealership in 5 years so, i may be thinking something totatly different.

Also if i remember right, i used to lay the carb on a 45 to adjust it. I think i did it that way. I also have this cute little driver that i may have used on the magnum carbs. Like i said its been so long that i may not be remembering what i am thinking.

 
#4 ·
I decided that it was probably something else. I ended up adjusting the throttle cable on the handle bar and then reset the idle screw. It seems to be working. The mixture shouldn't be off from just sitting around. I use stabilizer in all my gas, and the fuel filters are pretty fresh. There is a slight miss/stutter at WOT, but I may need a new plug. If you have any suggestions about the idle, bring them on. Before I adjusted the cable, the engine missed badly and would stall at idle. I had to turn the idle screw in to the point where the engine was revving enough to move the ATV without touching the throttle. With the cable slightly adjusted I get decent idle and the ATV isn't moving on its own. I just have the high speed miss/stutter.

Thanks,
Tom
 
#5 ·
Tom when you adjusted the cable did you make sure you did it by the book. You have to have play in the throttle. If it is too tight the etc switch can not work and you will find yourself in a wideup throttle postion, when you dont want it. Also how much play is in the choke. I think that may have been the problem i was thinking about.
 
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