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Discussion Starter #1
I have a 2002 Polaris Classic 500. Engine runs great, idles great, full power at take off. But at 40 mph, the engine bogs out like it is only running on one cylinder. If I slow down to about 25 mph, full power again and motor sounds fine. Then up to 35-40 mph it does it again. I changed the plugs the first time it happened and everything worked fine for about 5 miles, then it started again. I checked the "in tank" fuel filter (just a screen), and that looked very clean. Any ideas?
 

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Some thing in the air box;;; a weak clutch spring/ jamming problem,;;; carbs way out of sync./one choke stuck/slide,needle put together wrong ;;; loose engine mount.......
 

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I already checked the airbox, which has no obstructions. Have not done any adjustments to the carbs, so I don't know how they would have just gone out of sync or put a needle together wrong. If one choke was stuck, it wouldn't run good at take off. If there was a weak clutch spring or a loose engine mount, would it cause the motor to react in the way that I described?
 

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Thorough cleaning of the carbs. Then...


Carb sync:

- You need to adjust the free play in the throttle so that there is about 2-3mm of play. This is necessary for the safety switches to function properly.
- With the kill switch engaged and the key off, zip tie the throttle wide open (or have a buddy hold it).
- Remove the airbox so that you can easily see and access the intake side of the carbs.
- Ensure that the slide is installed correctly with the cable inserted correctly into it.
- Ensure that the slide cap is screwed on all the way.
- Ensure that the top edge of the carb slide is -just- above the bottom edge of the carb intake throat. If it is not, adjust the cable on the slide cap until it is.
- Repeat for each carb.
- Remove the zip tie / release the throttle lever.
- Rest the solid part of the drill bit in the carb opening "the long way" and adjust the idle screw until the slide -just- comes in contact with the bit. This will give you a reasonable starting point for the idle.
- Once all of the carbs have been adjusted, slowly squeeze the throttle and ensure that all of the slides begin to move at exactly the same time and go up exactly the same amount.
- Adjust the air screws according to the manufacturer's setting.


Adjusting the choke (enrichment) plungers:

- Get a thin gauge piece of solid wire and bend it at a 90 degree angle about 1" from the end
- Remove the airbox so you can easily access the intake side of the carbs
- Apply the choke
- Slip the bent section of wire into the enrichment hole on one carb and release the choke - make sure that you can not easily pull the wire out
- If the wire comes out easily, you need to screw the plunger adjuster into the carb body until you feel it contacting the wire and keeping it from moving
- Screw the adjuster in another half turn from that point and tighten the jam nut
- If the wire does NOT come out easily, pull on the choke lever until you feel tension in the cable - you should only have to move the handle a small amount after you feel tension before you can remove the wire
- If, after lightly applying the choke, you still can't remove the wire, you will need to unscrew the plunger adjuster from carb body
- Unscrew it until, with the choke off, you are able to remove the wire then use the process above to adjust it correctly


You're now ready to start the sled and tweak the air screw and idle settings until it's where it needs to be.

Drain out the fuel, add a few ounces of SeaFoam (concentrated carb cleaner), put a gallon or two of gas in (fresh), then run it. You should notice an improvement in it as it runs. Then you can toss a couple of ounces of SeaFoam in a tank of gas for the next couple of tanks and you shouldn't have any issues with carbs.
 

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Please start your own thread with all the information and problems it is having including model, year and make. As this is an old thread and the person has not been back.
 
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