KX500 detonating

[bvaughn]

I just got an 02 500 last week. I took it out for the first ride in the woods last weekend and noticed it pinging a good bit making me think i need a little higher octane. I was running 50:1 klotz with 93 pump gas. I know the 500's have pretty high compression (from the bruises on my foot lol ) so Ive been thinking about trying out a race/pump mix or 100% race gas but I have no experience with race gas. Does anyone have any suggestions on brands, types, race/pump ratio's, leaded or unleaded or is this even the right way to go about solving this problem. I have never had a detonation problem before.

Thanks

[xDCxSMOKE]

try to get at least 98 octane pump gas , have problems in my 1986 yz490 running below 96 octane

use bp ultimate 98

also check your carby settings you might be just running to lean ,

what are you ratio premix ?

oh btw you think the kick back on a kx500 is bad , try a XT500 it put me over the bars with a chunk out of teh back of my heel and done my akilles tendent lol

filled my boot with blood 15 stitch's later i was ok

haha love the big bike's

[bvaughn]

LOL ya their pretty rough this is my first big bore 2T and i love it so far a bit scarey at times thou. I did think about it running a little lean it was pretty cool that day the other couple of times i rode it around the house it was warmer and i didn't notice any pinging.

[sintax]

honestly the CR is pretty low on the KX500s. Most people never run more than 91 octane, i've used 87 in mine during a pinch and it runs fine.

I'd verify the head is not milled, and if it is you may need to adjust the squish.

Next you will want to verifiy the timing. If either of these is off you'll get the detonation.

I guess you could also check the spark plug and ensure its the right temp.

[bvaughn]

I know the head is completely stock the motors never been into its practically a new bike only has maybe 30-40 hours on it

[NVDESERTPETE]

http://kxriders.com/

[sintax]

I know the head is completely stock the motors never been into its practically a new bike only has maybe 30-40 hours on it

In that case, something is wrong...

I'm gonna vote either A) timing is off or you are mis-identifying detonation. The KX500 does have kinda a unique sound...

[zz3gmc]

I use Cam 2 110 octane in my 500. It would ping in high load/ heat situations such as deep sand or tight woods with pump gas. Mine is mainly a woods bike and have done a few mods to smooth it out and also alleviate the pinging. I use the optional thicker head gasket, Service Honda FMF KX500AF Gnarly pipe and Q silencer (dont know if the pipe actually helps with the pinging but the head gasket does) 14 oz fww, Boyesen reeds and the timing is at the stock setting. Its very smooth and super easy to ride in the tight stuff.