07 YZ450F low end engine ping....

I will try to set this up the best I can.... I bought an 07 YZ450F last month and absolutely love it. Great looks and runs as good as it looks. I had it jetted and dyno'd last week, 155m, 45p, and 3rd clip on the needle. I live in the Rocky Mountain region of Montana and ride at or above 3000'. After jetting, my bike runs better than with the stock setting, which ran rich, but I am still noticing what sounds to me like the engine is pinging at low rpms. I have been running pump gas through it and not sure if this is the problem or if it may be something else. Any ideas as to what I should do next?????

I will try to set this up the best I can.... I bought an 07 YZ450F last month and absolutely love it. Great looks and runs as good as it looks. I had it jetted and dyno'd last week, 155m, 45p, and 3rd clip on the needle. I live in the Rocky Mountain region of Montana and ride at or above 3000'. After jetting, my bike runs better than with the stock setting, which ran rich, but I am still noticing what sounds to me like the engine is pinging at low rpms. I have been running pump gas through it and not sure if this is the problem or if it may be something else. Any ideas as to what I should do next?????

i could be wrong buti think its the gas

what octane you running?

should be running 95 an up

Premium gas here is 91 octane. I think I am going to start mixing premium fuel and racing fuel at a ratio of 4:1. This should put the octane at about 95.8 to 96.

ya give that a shot

The gas is not your problem. Different parts of the US sell different octane gas. The octane might have to do with altitude but i am not positive. The highest octane gas is 91 that is sold at the typical pump in colorado. Of course there is always different options for gas.

I always run 91 octane and so do all my friends on yamaha 450's and it has never been a problem.

Did you install a skid plate and possibly not put in the foam? There are tons of possible scenarios that it might be?

I will try to set this up the best I can.... I bought an 07 YZ450F last month and absolutely love it. Great looks and runs as good as it looks. I had it jetted and dyno'd last week, 155m, 45p, and 3rd clip on the needle. I live in the Rocky Mountain region of Montana and ride at or above 3000'. After jetting, my bike runs better than with the stock setting, which ran rich, but I am still noticing what sounds to me like the engine is pinging at low rpms. I have been running pump gas through it and not sure if this is the problem or if it may be something else. Any ideas as to what I should do next?????

No skid plate or any other mods.

When you say that you hear pinging, you mean only under a load at lower RPM, right?

Yes. Only under load at low rpm.

Yes. Only under load at low rpm.
Then that does in fact sound like pinging (detonation), and most likely can be corrected by improving the octane of your fuel. The first thing to try is to change brands. Normal pump premium is generally adequate unless it's very hot, you're jetted very lean, or you're just plain running too much throttle at too low a speed, which is unlikely, IMO.

If that fails, a cheaper solution would be to add 10-15% toluene to the fuel (good hardware/paint stores). You can go as high as 20%, but at over about 12%, you'll need to jet up for it.

i could be wrong but I think its the gas

what octane you running?

should be running 95 an up

The requirement for 95 octane in the manual is for 95 octane by the Research method (RON). This method produces high octane numbers that the Motor Octane method (MON). The difference is fairly significant, such that 95 RON is equivalent to about 87-88 MON.

U.S. gas pumps are labeled by law with the average of both these test methods. You see it on the pump as (R+M/2). So, the reality is that U.S. pump gas labeled as 91 octane IS 95 octane by the research method, and meets the fuel requirements of the YZ450.

Thanks, I will try a different brand of fuel. What do you think about running a 50 or 51 rear sprocket to increase the rpm's at lower speeds?

If you are mostly trail riding and top speed is not an issue, you could try that.

Good advice from Gray,I would also like to add watch where you buy your pump fuel from. Today with gas prices the way they are ,super unleaded(premium) is not moving.God knows how long it sits in the ground,I do not trust pump fuel,just too risky for my bike. I have no added compression,I still will not run pump.

how much is gas where you are?

Thanks, I will try a different brand of fuel. What do you think about running a 50 or 51 rear sprocket to increase the rpm's at lower speeds?

Just a shot in the dark, but have you eliminated chain slap as the source of your "pinging"? What I thought was pinging turned out to be a loose chain slapping on the slider. It was freaky how similar to pinging the noise was especially when lugging the motor.

I will check for the chain slap. Fuel here is running about $3.35-$3.40 for premium.

I will check for the chain slap. Fuel here is running about $3.35-$3.40 for premium.

Do the 07's come with the non-O-ring chains, and if so are you still running it?

They come with the same cheap trash they always did. There are rumors of an upgrade at the OEM level.

They come with the same cheap trash they always did. There are rumors of an upgrade at the OEM level.

Thanks Grey!

To the original poster: If you haven't already, you might want to upgrade to a good O-ring chain and then check for "pinging" before you pursue other avenues.

Thanks. I saw a thread that discussed the chain issue and wondered if this was something I should worry about?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now