Hey guys,
I am new to two-strokes, and am getting a 2005 KX 85. I am wondering if I need to get the higher octane gas. I know with my old 4-stroke 80cc it didn't really matter, but I know you have to rebuild the piston rings and piston every once in a while on 2-strokes. Also, what gas-to-oil ratio should I use?

I live at 1200 ft. elevation in NY...

Thanks!

At 1200', you'll probably have to jet. Just watch for the spooge from the pipe and silencer. That will be the tell-tale sign it's too rich. Unless the previous owner already jetted it. Most don't.

As for mix, run a god synthetic oil like Amsoil Dominator, Maxima, etc. Stay away from Benol type oil. In the minis, it's good to run at 32:1. But you can run at 40:1 on a synthetic and be fine.

Gas - Run 92/93. For a few cent's more it'll be much better than the cheap 87/89 stuff. Thos few points mean alot. If you run any higher, say, 100 octane or above, you have to jet for it.

Since your new to "pingers", here's a list of newb info:
1. get a manual
2. Read all the FAQ articles in the FAQ section above.
3. Before asking a question, do a search using different keywords. Most likely what you're asking about has been discussed within the last 2-4 pages of this forum.
4. Don't be afraid to ask anything, many of us here are here to help. We don't know it all, but we know alot. Even we ask each other for help/info.
5. Oh and welcome. You're on the best and most knowledgeable forum there is.

I don't get too serious about the minis anymore since only my daughter rides for fun and my son is on big bikes.
BUT, a member on here, JBFL, is on top of the latest and greatest for these. he'll keep you squared away.

EDIT: And watch out tfor those old and grumpy guys. Chokey

Edited by SAPPERS, 06 April 2012 - 07:52 AM.

Oh, forgot to add this in there. Run ATF type F in the tranny and change every 8-10 ride hours. You'll be thankful you did.. It's cheap and excellent for the trans & clutch.

but with it being an 05, find out as much as you can about it from the previous owner. And if you don't know him or the history of the bike, only believe half of what he tells you.

Basic special tools you'll need to help you along.

1. Compression tester. $30 at any auto parts store.
2. A good dial caliper, also $20 or so at any parts store.
3. An impact screwdriver, $14 at any parts store. Most are even 3/8" drive so you can use a socket on it if needed.
4. ***A good in-lbs torque wrench*** very important when torquing the head.

Edited by SAPPERS, 06 April 2012 - 07:48 AM.

here's a pic...

http://tinypic.com/r/2q0rg91/5

Looks very clean. Get some tires on that thing though. I suggest Michelin Starcross MS2 front, MH3 rear. Great for that NY topsoil.

yeah...the back one doesn't look too bad, but the front looks pretty worn...

My oldest just got off 85's and my youngest is on them now (2004 & 2012).

Here's what I use:

93 octane mixed at 32:1 with Maxima K2

No Toil Filters and oil (changed after every ride)

Type F ATF - I buy in 2 gallon jug at Rural King. I change it after every weekend of racing. It's cheap, easy and part of my routine.

Check coolant often (I use Prestone 50/50 mix), all our Kawi 2 strokes seem to use a little each time out.

Okay... thanks

For an 05' that thing is mint!!!

Great advice from Sappers as always.

yeah, I know!

sorry to thread jack but still on topic.  since i didnt read before, and dumping the fule will cost me some$$ to switch.   i loaded up 5 gal and some maixma k2- shop said 16 0z=32:1  correct?  before reading i filled up with 87, will that be ok for a couple gal worth, and then mixing in 91 or higher say at 2.5 gal with 8 oz of premix, until i cycle through and then run completely higher octane?  i'd hate to lose 45$ and turn that in to 50-60 more to refill with higher octane.  thanks again for the advice guys.

Hillbilly. my suggestion is mix up another 5 gal 93 octane and mix together. if you have a 3rd 5gal can, mix 50/50, then dump one of the original into the other. you should be fine. If you were around me. I'd give you a gal of 110 and you'd be real happy.

Edited by SAPPERS, 06 April 2012 - 11:40 AM.

Fuel cost$$$?

I use VP fuels C-16 (117 octane) mix 50/50 with VP U4.4 oxy (103 octane) to feed the beast!!!

Damn it'll be nice when the kid gets on 125's these Supermini's can break a guy!!!LOL

and where do you buy that high octane fuel???

Listen to SAPPERS, he's very knowledgeable (on most things) and won't steer you wrong.

 SAPPERS, on 06 April 2012 - 07:34 AM, said:

But SAPPERS, you know that you and I will just never agree on this. 32:1 just isn't enough oil for a 14,000 rpm mini that gets ridden hard, and I won't even run 40:1 in my 250. The lower rod bearing has long been the Achilles Heel for Kawies minis (and the 250), and there's just way too much anecdotal evidence that points to that bearing lasting longer with high oil concentrations like 24:1 or greater, especially for a rider that knows how to keep the engine screaming like it was meant to be ridden.

But everything else you said was right on.

Quote

Who you callin' old, you old fart...

 HILL_BILLY, on 06 April 2012 - 10:03 AM, said:

I wouldn't run the 87 octane in any two-stroke. I'd dump it in my truck and use it in my lawnmower and get proper fuel for the bike.

16oz of oil will give you 32:1 for four gallons of fuel, not five. 32:1 is four ounces of oil per gallon.

hmmmmmmmmmmm so I guess I'll just have to try both myself...

 JBFL, on 07 April 2012 - 03:16 AM, said:

Why do you use C16? C12 is a much easier fuel to tune for in our engines. C16 isn't particularly well suited to our engines, it's primarily intended for forced induction engines.

 Chokey, on 08 April 2012 - 12:40 PM, said:

17.2 to 1 compression, I didn't feel mixing 103 and 108 was enough octane for that compression. 117 and 103 is a closer match for octane needed.
Brent at TDC and I are going to take it up another notch, Brent will be o-ringing the cylinder to head to help. Another reason for the o-ring is the frame flex lifting the head, I am doing head gaskets about every 8-10 hours right now.

Edited by JBFL, 08 April 2012 - 03:13 PM.

I knew if I said something about him, he'd respond HAHAHAHAHAHA!!
But, to me, 24:1 is pretty thick. True meaning of the word "smoker". But if you have any doubts about lubrication, Chokey is right. It will make your internals last a long time.

Especially at half past slow...j/k old man.