I have a 1988 polaris 250 trailboss. At idle the engine makes a fast "ping" sound. Kinda sounds like coming from the cvt area or the lower half of engine. When I speed up the idle a bit it goes away. Dont hear it while riding or at high rpms either just at idle. What could this be?

 

maybe piston slap? being that old maybe the clutch is wearing out, hard to tell.

 

I had this noise also on my Scrambler. Sounds like your primary clutch is worn out. I rode mine for 2 years with the noise but it is very annoying. Finally replaced primary clutch last year due to the pulley wearing a groove in it and it fixed the noise as well. Hope this helps.

 

You are most likely missing a button in your primary clutch that i causing the slack in the clutch at the low speeds. I had the same problem with my sportsman. I also have an 88 trailboss. Check out your primary.

 

Explain the process to replace this button. Will I have to remove the primary?

 

the buttons are in the secondary clutch not the primary, there what the helix rides on.

 

check this im not sure what your bike is but if you click on the right one and then go look at the driven clutch break down, you'll see the buttons. their is 3 of them.

 

I dont know the noise sounds like it is coming from the drive clutch or from within the lower half of the engine. It has been rebuilt but I dont know when since i bought it used.

 

there are buttons in the primary, most people thinkof clutch buttons as being in the secondary but there are also 6 rubber buttons in your primary. You will have to pull the primary off and pull it apart. These buttons are near your weights. They are round spacers and you can only see a little bit of them. pull off your clutch and you will see them.

 

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