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I have a dual-sport ride this weekend in southern Indiana and I plan to ride my '89 KDX200. All the fuel stops are in small towns and 87 octane gas is all that will be available. I always run premium gas and I'm nervous about using 87. Does anyone here have any experience using 87 in their KDX? Any pinging or other trouble? I have a DG pipe and RB carb and head if that would matter.
I did some research on octane booster and found that toluene is the main ingredient in most of them. 10% toluene is supposed to add 2 full octane points and I even have a jug of it at home. The problem is that I'd have to carry almost a gallon of it to get my octane up for the whole trip.
What do you guys think?
Is 87 alright or is it asking for engine damage?

I have a 98 kdx 200 that is plated. I do a lot of dual sport trips on it. My bike is completely stock. I run the high octane just because it's easy to choose it at the pump. I have however run the regular low octane gas before for a long time and have seen no performance advantage nor damage to the engine.

87 resists pre-detonation to around a 9:1 compression ratio over that and you need a higher octane. I believe the 90+ KDX is around 9-9.5:1
So you may get slight pre-detonation but probably not something you would notice unless you've had the head milled (increases compression ratio) or a fresh top end.

Personally I wouldn't worry to much about it..but if you are worried drain your tank and put some 87 in there and warm it up and see how it does.

Just to be safe, why not retard the timing for your trip? As a plus you'll get more over-rev!

Thanks for the info, guys. Retarding the timing a bit might not be a bad idea but I think I've managed to work out some logistics so that I'll only have to fill up with 87 at two gas stops. I'm going to carry a quart of toluene with me and stash another quart at one of the gas stops before the ride. This will let me get the fuel up to about 90 octane. I think that should be alright.

Most likely as long as you don't wring it out a ton you won't have any problems. Hear detonation, back off!

Be sure you follow this advice. One time I didn't, and ended up with a nice hole in the piston crown.

KDXohio wrote:

Excellent Chart , The new 4 stroke engine design " combustion " makes this a little dated as those dam
things can run a 12:1 engine on 91 octane all day. I'm not an engineer but it has to do something with the
Indy Car engine model.

Sorry to sway your thread :)

87 on a stock engine , you should be fine.

Back to your initial question ,,, Pick up some qts. of NON-ethanol 94 / 95 octane fuel at your local small engine / John Deere / or auto parts house.

Something you could put in a back pack.

I highly doubt it would be a problem. I often bought shitty gas sold out of empty glass Coke bottles on the side of roads here, and never had any visible issues. I'm sure the 87 octane you'll be buying from actual pump stations will be way better than old dirty gas I buy that's sitting out in the sun all day.