yz250 pinging/tinging noise

Hello ! Any help would be greatly appricated. I am experiencing some noise's on my 2013 yz 250. About 60/70 good hrs on it. I know im runing a lil rich on jetting and havent rode for a cpl weeks so my pre-mix would be 2 or 3 weeks old aswell. The bike starts first kick and warms up no problem. Took a putt around a track but as soon as i was 1/2 to 3/4 throttle i could hear a pinging noise. Sounded great in the low end. As soon as the rpm are up (any gear) u can defintly hear somthing is wrong. Any answers or pointers again would be greatly appricated. Thx in advance. G

Also forgot to say that bike is completly stock except for fmf turbinecore 2 but that shouldnt matter. Kinda was thinking it was detonation/pre-detonation? Gunked up power valve or somthing like that? Air filter is clean and gear oil is fresh. What i dont get is it starts fine and runs fine 0 to 3/8 throttle, would a dirty carb make it run and start like shit ? Im no mechanic but not mechanicaly inclined either to tinker with shit. Again thx for your expertize

I'm guessing a plugged or dirty main jet.  Check this chart out on how they affect throttle position:

 

http://www.jba.bc.ca/JBCycle/Resources/jet-chart.jpg

 

And of course the obvious, new gas...

Edited by Carcinogen

low octane fuel? 

Manual say 95 or higher and all i can get is 94 pump gas. Been looking into getting vp or some shit like that. I was going to put a fresh top end in but should i get a head mod? Set squish to .48 or .50 i think stock is .70. What would the benifits be? Would 94 octane benifit with that and how much does a head mod cost?

are you sure it the engine pinging?  mine does it to but its actualy just the little bearing in the kickstarter. if i hold the kick starter hard up against the frame while doing reving it, it doesnt make the noise

Manual say 95 or higher and all i can get is 94 pump gas. Been looking into getting vp or some shit like that. I was going to put a fresh top end in but should i get a head mod? Set squish to .48 or .50 i think stock is .70. What would the benifits be? Would 94 octane benifit with that and how much does a head mod cost?

I believe that the pinging noise is pre detonation. Replace the fuel and see what difference it makes. After 60-70 hours I would replace the top end. A head mod (milling) calls for higher octane fuel. So if you don't have a problem spending money on some high octane stuff.. go for it

I'd do the top end and send your head out to eric gorr or rb. Measure your squish with a piece of solder per the thread. Then They set the squish which will decrease detonation. Then depending on which fuel you want to run they re chamber the head. This way you can have correct squish which will really clean up your jetting and can run on pump fuel. It's the best $40 you can spend on your yz250 and I'd say a requirement for jetting and detonation.

Also check your timing per the timing thread. My last 250 was over advanced from the factory. I retarded it some and the pinging went away. Check yours before you ride it next.

Thanks alot my fellow dirt shredders. I will tinker around abit more. Maybe ive overlooked somthing and could be over reacting as i dont want to cause more damage. As i would consider myself a newb, there will most likly be more quetions comming soon haha. Hopfully its a simple as shitty fuel and a new top-end. Thx again bros ! G

I mix 50/50 (pump and VP 110) and have no issues with pinging anymore. Mixing it with the pump gas makes it more affordable to run race gas. I have a stock 06 motor and no ping Noises at all. It runs great.

That stuff we all buy from the local gas station isn't very good fuel when it's brand new! Much less so after a week or two!!

 

And to think, we used to laugh at the "fuel" you bought in Baja!!! I'm here to tell you that Baja gas is better than that crap we get to buy now!!!! :banghead:

I mix 50/50 (pump and VP 110) and have no issues with pinging anymore. Mixing it with the pump gas makes it more affordable to run race gas. I have a stock 06 motor and no ping Noises at all. It runs great.

Did you have to rejet to run this combo?

Did you have to rejet to run this combo?

Nope. Stock jetting. Good throttle response. The bike is completely stock except for a r304 silencer. I use amsoil dominator at about 40:1

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