Detonation and Octane boost

[ElliotG]

Hello all,

My 5 hunnie has some detonation going on, and am thinking about trying some higher octane fuel.

I haven't cracked the head open yet, my compression is just shy of 115, so detonation isn't related to high compression.
I am probably due for a new piston/ring.; I have a trip coming up for SandMountain, and don't have enough time to freshen up the top end (parts availablity).

I really don't want to purchase 6 dollar a gallon stuff, so am considering using tuolene or xylene, depending on what is available . I have seen this done for other applications, was just wondering if this might be harmful for a two stroke?

I am worried about running in the sand for extended rides, don't wan't to hurt the bike with too much detonation, so the octane boost is a temporary fix.

Thanks

[mikesmith]

I wouldnt suggest using that stuff found in paint thinner,are you sure your jettings right?I would rather run my jetting a little fat (rich) and put up with the "blubbering" (how it runs)of the bike and not worry.

[Kawadougie]

I would definitely replace the piston and de-carbon the head.  Also check your ignition timing.  For a quick fix you can use any commercially available octane booster.  I used to use them when I raced high compression 125's.  The only downside is that it will stain the inside of the tank an ugly brown color.

[alan]

Here is a post on another site which talks about Octane Boost!

http://yz490.com/index.php?name=PNphpBB2&file=viewtopic&t=26&highlight=klotz&sid=3a79aaf81fbebcdcdfc9799ebae9de87

Klotz works great!

Alan

[KXcam22]

I have had good luck with octane boost.  But....for riding in the sand I would definitely put a fatter main jet in.  The extra load is considerable in sand and you are better to be a tad on the rich side. Cam.

[ElliotG]

Thanks! You are right, I could have some carbon buildup on my piston. I am not sure when they were last done. I have seen advice from Paul to the effect of using compression as a basis of new piston/ring. Being as I am at 113 or so, I am probably due.

As far as the octane boost goes... I have used Klotz, was just wondering if anyone had actually used straight tuolene or xylene, mixed in with the gas of course  

Thanks

[Paul]

These are called service limits. If you're at 113lbs of compression you are due for a new topend.

I have seen advice from Paul to the effect of using compression as a basis of new piston/ring. Being as I am at 113 or so, I am probably due.

Check the FAQ under specs for the Service Limits

[ElliotG]

Does is make any difference whether the bike is cold or not when runing a compression test?