06 yz250 not sure if I'm hearing pinging?

[BTYZSquad]

I have an 06 250, bikes always ran good, but yesterday I noticed when I rode my bike into my trailer after I rev it it sounds like there's a little rattle near the pipe area when the Rpms come back down. I've never heard a 2 stroke ping before, so I don't know what sounds I'm supposed to look for. The previous owner mixed vp and pump gas 50/50 so I'm not sure if he did that to fix pinging? I've ran about 5 tanks of pump gas since I've got it and it seems okay but that noise didn't sound right. It didn't do it at idle or when revved it did it when I let off the gas and came back down. I also have an air port 5 min from me that sells 100ll for 4.45 a gallon. I can't afford race gas so should I mix 100ll and pump jut for peace of mind?

[gedakbx]

We just ran ours in Southern California for 16 days on 11L of 91 shell with 5 L of 100LL ran great. 

[Doc_speeder]

Not likely ping I don't think.  Not under those throttle/load conditions.  Maybe something loose?  Like just a vibration or harmonic rattle?  Pipe mount maybe?  Pipe tweaked a bit and hitting frame etc?  Just take a few minutes and verify that's not the problem, then try some better juice. 

[bikedude987]

I've had it ping that sounds JUST like that.  I usually hear it on the trail though, after a mid-full throttle blast then chop the throttle.  When you let off (and it gets lean) it pings.  Sounds like something rattling against the pipe, just not quite the same resonation.

 

[BTYZSquad]

Hmm. Maybe I'll try getting a video. I'm just not sure what detonation really sounds like. Like I said I live a few miles from an air port so I might just run a mix of 93 and 100ll.

[jay winchell]

they ain't designed for that much octain. you might get away with it but put it on a dino. you can only produce so much horsepower before you go backwards 

[Doc_speeder]

they ain't designed for that much octain. you might get away with it but put it on a dino. you can only produce so much horsepower before you go backwards 

It sounds like you don't fully understand octane...

Higher octane fuel does not magically create more power, but actually prevents fuel from burning too rapidly or "exploding" in an unpredictable manner.

[jford312]

My 2016 Yz 250 is doing the same thing right now. Weird vibration noise coming from the front of the expansion chamber. The gas in it is currently kinda old (about 5 weeks). I'm going to mix 1 gal race gas to 4 gals of ethanol free fuel and ride this weekend. Will let you know if this fixing the problem. Anyway, does pinging cause any harm to the motor?

[EmpireofDerp]

they ain't designed for that much octain. you might get away with it but put it on a dino. you can only produce so much horsepower before you go backwards 

Nice troll man. 9/10 [emoji106]

[BTYZSquad]

My 2016 Yz 250 is doing the same thing right now. Weird vibration noise coming from the front of the expansion chamber. The gas in it is currently kinda old (about 5 weeks). I'm going to mix 1 gal race gas to 4 gals of ethanol free fuel and ride this weekend. Will let you know if this fixing the problem. Anyway, does pinging cause any harm to the motor?

If you ignore the problem yes, but if you heard it a few times and you try running race gas it should fix your problem and your engine will be fine.

[BTYZSquad]

Well I'm not too worried about pinging right now, noticed my bike has been smoking a lot since I changed my oil. Only about 400ml came out and It smells kind of like bitter too not at all like super m. I'm gonna say I need a new clutch side crank seal Also my pipe was very loose at the mount so that must have been the noise.