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So I have been reading some recent posts asking about the fuel/oil ratios and have payed attention to Indawoods, etc. advice on running 40:1 over 32:1
I am currently running the 32:1 ratio but want to switch to 40:1
When I installed the Wiseco piston this winter I removed the whole jug without taking the cylinder head off. I did not bother with the full tear down because the bike is obviously new. I did flip the jug upside down so I could get a glimpse of the dome and saw some spooge baked up there. I have also noticed that when I pull the butt-plug out of the silencer it is taking on some wet spooge on the little rings. (You know, the plug you put in the silencer before you wash the bike)
I always leave that sucker in when the bike is put away!
Anyway. The 40:1 ratio makes perfect sense to me. Am I going to have to change any jetting? i.e. bigger pilot? It sounds like a negative. Your saying that the woods bike should be run at that ratio.
Just wanting someone to clarify that for me cause I get nervous screwing around sometimes.
Thanks

remember that going from 32:1 to 40:1 makes your bike richer, not lenaer as some think. Re-jetting is always a good idea after changing ratios, oil, etc....

Yeah, you need rejetted right now, and changing to 40:1 will worsen your problem. People just run 40:1 because it's more than suffieicient w/ modern synthetic oil, it's easy to measure, and will save $ on oil. Sooooo.....rejet regardless, but if you're going to switch to 40:1 do it first.

Think gas to air ratio when you think rich or lean. The oil has nothing to do with it.

40 parts fuel or 32 parts fuel.... +Gas=Rich +Air=Lean

I don't know if that makes sense to you... but it does me.

Okay, So I will be looking to go smaller (leaner) on the jets.

What is in there now and what is your elevation?

42 pilot, R1173L needle in the 3rd postition from the top, 148 main and the air screw at 1.5 turns out.
Elevations are roughly 1,500' to 3,500' above sea level.
Temps at this time are in the 40's
Since I have only been running at 1/2 throttle max. for short periods of time (actually, I would'nt even say half) for the top end break-in, I pulled the plug and it is kind of a snickers brown. Not cardboard tan.
Tried fiddling with the air screw and really did not notice any changes in idle. Just found that throttle response seemed to be fine at 1.5 out.

It's a 220 then?

Yes. You can see my complete list of mods in my profile.
Not RB'd, yet.

Oil does matter when it comes to residue left behind. That you have some oil on the inside of your S/A outlet isn't really a big deal.

Jet correctly by known tell-tales (plug reads) and good old seat-of-the pants pull. Do NOT jet-by-spoo.

The color of the insulator (cardboard tan, snickers brown, mondo mocha..whatever) has nothing to do with whether your jetting is correct. Well, it may tell you it's NOT correct, but it will NOT tell you it's right.

Carbon under the piston crown is NOT a rich/lean indicator.

Not the right place/time to say this...but there is a school of thought that says you must seat the rings with pressure..and that doesn't happen with a heat-cycle, take it easy kind of break in method.

You say '...yet'. You're planning on modifying your carb? You've read the 220 benefits a good bit by having the head done, too? Sending them both in at the same time will save you some shipping $$.

Yes indeed. I have actually attended that school for years with my KTM.. She comes to much faster if I go out and give her a good running through the gears after doing the top end. It is quite the quirky beast so I have approached the sweet little KDX with care. I am ready to go at it this weekend though as I found a way to connect two loops in my area with one monster Mountain between them. Got the GPS all tuned up and picking up the Pirelli MT 32 (120/100-18) tomorrow.
Talked with Jeff Fredette today and he thinks that since I am using Spectro 321S that I should stick with the 32:1 and swap the 148 main for a 145. Done. So now I wait with little sleep until Saturday!

DEFINITELY send the head in with the carb when you get your RB mod. I didn't and wish I had. The head mod on a 220 feels to me like it adds 4-5 hp to the low end. It made mine feel a lot more like a 250.

<edit> I ride at very high altitude though, so the difference may not be as big for you.

How does 40:1 ratio richen the bike instead of leaning when your actualy adding less oil to the gas than at 32:1? just curious. I thought that with less oil it would come in alittle leaner because the theres more gas than oil in the mix. Also where does octane come in to play when mixing fuel and oil?

Never mind, just answered my own question.

Funny how after you post something and you read it then it 's like someone hitting you upside the head. Oh yeh, I get it! Deeerrrr

Careful, or you'll have to start using Colorado Mike's avatar.