I recently bought a 2000 SC 400 4x4. I have gone through the 4 gallons of mixed "break-in" gas. During the break-in period I ran at varied throttle positions and didn't keep it at any one position for an extended period of time. When the engine is warm, I have noticed a "pinging" sound in the engine when I am at about 1/4 throttle. The sound goes away if I let off the throttle or give it more throttle. I have noticed this for a while on my 1996 Trail Blazer when it is at about 3/4 throttle also. Is this anything to be really concerned about? Any thoughts would be appreciated. Thanks..

 

If it goes away, no big deal, just don't run it continously where it pings. Your other atv was doing this since '96 and is still going, isn't it?
Farmr

 

Try a higher octane of gas, see if that makes a difference.

 

Go to 92 octane fuel.If the pinging goes away,it is an octane problem.Your next tank of fuel,try 89 octane.If it stops pinging with 89,it is ok to stay with it.===Bill

 

I agree use a higher octain gas, I have a 2000 POLARIS SCRAMBLER 2x4, I ran it on super unleaded pump gas since the first day I bought it, and it runs great!


Also, try using POLARIS SYNTHETIC GOLD high proformance 2-stroke oil,


Your engine is high proformance, even though it's stock.


LONG LIVE POLARIS!!!!!!!!!!

2000 POLARIS SCRAMBLER 400 2X4

SCRAMDADDY400