[tjmoening]

Alright experts, I have a question about a "Pinging" noise when my 97 Mach 1 idles. I was tinkering with my Mach 1 today and after I cold started it, I heard a "Pinging" noise. Seems like there is a pinging noise as the motor cycles, only at idle: "ping, ping, ping, pah-ping ping, ping, ping, ping, pah-ping, ping ping"...if that makes any sense. Once the motor warms and I take it for a short spin, the noise goes away. I am trying NGK BR9YES plugs and have them gapped to .018. I think Ski Doo came out and said to run BR9ES plugs in this sled after the BR10ES it originally called for were not hot enough and fouled easily. Could it be these plugs firing weird? Could it be poor gas (Running 91 octane)? Could it be my primary clutch making a funny noise because of worn parts? Could it still be something more major like a crank bearing? My clutch spins tight, with no play and I hear no funny noises from the crank when I manually spin the clutch, turning the crank with the motor off. The sled runs great and I really don't want to have to stick money in the motor for a "What if"....although that could become an "oh crap" if I don't I suppose! Any ideas or advice for a mild "Pinging"? Thanks!!

 

[kccats]

Pinging is preignition. Or the pistons are slaping?

 

[IRONDOG]

More than likely noise from pistons rattling in the bore till they get warmed up. Wiseco pistons can make a lot of noise when cold. If the mileage is more than 3000 on those
pistons you may want to tear it down and check the skirt clearance.
Jerry