Knocking Noise?

[HULKSTER]

When I bought the 2003 KX500 he told me that the knocking noise was normal. He said he was told that the powervalve had something to do with it. I dunno.

I have had other KX owners tell me the same thing about thiers making the knocking noise.....


Is this normal?

Everything seems fine.....

When ya crack the throttle....everything sounds fine....

[Paul]

Hmmm... the only noise I've ever had come from mine was due to detonation and that cleared up as soon as the fuel was over 95 octane like the manual recommends. OR, you can go the modded head route and run 'em on pump gas.

I have one thats modded and one thats on 100 octane all the time and neither make that noise.

[HULKSTER]

What modded hear route? Enlighten me.

I don't think there is any race gas around here....I will check soon though....

[Paul]

The inside of the head looks like it was formed around a nipple, the head modification smoothes the transition from the edge to the center where the sparkplug electrode is, this in turn drops the compression alittle and allows you turn run lower octane fuel

[HULKSTER]

Thanks....

I'm gonna ask today about the race fuel. I was told yesterday that one place has it...

If they do...I can run that at like 50/50 mix with Super...

If they don't...who does these head mods?

[Paul]

Eric Gorr did mine. Most all of the motorcycle / car speed shops will have some type of high octane fuel. Common names: VP Red, C12, FNL111, Sunoco Purple and many others. I use the 110 Sunoco Purple. in a 50/50 mix with pump 91 it yeilds 100.2 octane, ALSO remeber to store any UNMIXED fuel no longer than 6 months in a sealed METAL container. This preventslight from breaking the fuel down and only mix (oil and gas) what you can burn within 24 hours, oil qualities breakdown when mixed with gas.

Fresh fuel yields the best performance

[HULKSTER]

OK....I can get VP110. It is $6.00 per gallon!

Wow....that's expensive. I am gonna look into getting a drum full for a much better price.