Oil To Fuel Mixture?

[CODY_M11]

I WILL HAVE MY NEW 310 ENGINE REBUILT THIS WEEKEND AND AM WONDERING WHAT MIXTURE TO RUN? I WILL BE USING DOMINATOR AMS OIL AND VP113 RACE FUEL. STOCK CYLINDER AND 93 PUMP GAS I RAM 32 TO 1 BUT I STILL FOULED QUITE A FEW PLUGS. A BUDDY TOLD ME TRY 42 TO 1? WOULD THIS WORK?

[latheboy]

With my stock cyl, I ran dominator at 50:1 all winter on the ice. Didnt foul any plugs. Apon recent teardown, the lower end seemed to be well lubricated. I ran it at 50:1 because that is what Asmoil says to run it at. But as always, to each their own....

[CODY_M11]

YA I SAW THAT ON THE BOTTLE TOO. IM STILL KINDA NEW TO 2 STROKES SO JUST LOOKING FOR HELP.

[Honda 250r 001]

I never sacrifice lubrication on 2-strokes. All oils are mixed at 32:1 for me.

[ridered250R]

I'd listen to the bottle, I run Klotz 50:1 on race fuel. Works great. and two of my friends run AMES oil and they love it. You have to remember that too much oil can also hurt you, it can cause you to run too hot cause the gas actually helps cool, if even slightly, besides, whats the worst that can happen, burn a hole in the top of your piston, hahaha, just kidding that would be terrible. Plus - we don't want to be like all those banshee owners blowing blue smoke all the time.

[Deuce426]

I dont have my 250R together yet, but I run Dominator in my sled (Arctic Cat ZR 800) and It holds up fine in that. Figure on piston swaps in the sled from 2000-2500 miles, and the thing is usually singing between 5000-7500rpm all pending on how much I'm in the gas. This is all on 50:1 mix. I dont see how its any different for the 250R, especially how we do pistons and rings in these even more often. Oil has come a far way from the days of when these bikes were originally built. I'd break it in on 32:1 with a good conventional 2x oil, but then go to what the bottle recommends if you switch to something else like Dominator (especially if you run a power valve, which will keep it from fouling up).

Just my .02

[CODY_M11]

well im going to be running the vp c12 now which is 108 octane. so im thinking ill start some where like 40 to 1 than go from there. my buddy at the honda shop said run it strait and swhouldnt have a problem cause i asked bout breaking it in on pump gas and he said just run the vp.

[fearlessfred]

im with 426 on this. u should break it in at 32 to 1 with a good conventional 2 stroke oil and then switch over after break in. keep in mind that ratio changes have small effect on jetting so fouling plugs might be even more of an issue,after switching to 50 to 1 ( higher ratios will cause slightly richer jetting) usually fouling is from being to fat on the jettting and not oil

[Ruf Racing]

Originally posted by fearlessfred
usually fouling is from being to fat on the jettting and not oil

fearlessfred nailed it. If you use proper oil/gas mixtures, fouling plugs is caused from fat jets.

[CODY_M11]

ok explain this to me guys. :confused: whats fat/lean/rich all these mean? i am completley new to tuning carbs. what do you guys call coventional oil?

[fearlessfred]

rich and fat means to much fuel there is a really good thread on jetting somewere on this site on the oil we ment something like yamalube,non synthetic

[CODY_M11]

ok so why would you use a conventional oil to brak in then switch oil? same with y would you break it in at 32:1 than after move to 50:1?

[fearlessfred]

well breaking in is basicly seating the rings , the cylinder is honed to crosshatch and that helps the rings wear into the shape of the cylinder ,with ,a synthetic that process might not take place. so it would not hurt anything breaking in with conventional oil, on a 4 stroke iknow for sure that u dont use synthetic to break a motor in. on a two stroke i dont know for sure . im not familar with the oil u are using . maybe some one else can chime in here and as far as the ratio change goes, that is a practice that all the mechanics i know recommend for break in

[DB 450R]

http://airfoolers.com/?page_id=385

[fearlessfred]

great artical still wandering if u should break it in with synthetic does any body know

[Deuce426]

My only guess is that with conventional oils you have less fortifiers in the oil. Its some of these fortifiers that will go and line the cylinder walls. During break-in the purpose is to seat the rings on the wall and get them to seal. With these fortifiers, it will cover some of that abrasiveness more so, which will prevent a great seal. This is only a guess though.
You can break it in with synthetic as well, but there is nothing wrong with a good conventional oil... its cheaper and you'll be using more of it at first.
When you break in a sled for instance, you have the oil injection (you dont premix a sled normally) set at 50:1 or whatever is recommended, but also during sled break-in you premix the first tank or two as well so she is running more oil to aid in making sure its lubed up due to the tight tolerances early on. After that you go to whatever you wanna run and at its recommendation.

Heck there is nothing wrong with a good castor oil, and that style oil has been around for ages. In the end it comes down to what you want to run. The main perks of synthetic are it has better lubrication properties (if you buy a good one that is), which allows you to lean out the oil mix to what they recommend, which will burn cleaner (ie powervalves wont foul up as often... especially in sleds).

But also keep in mind, tailor what you're running to how you're riding. If this is a full out race motor, then more oil will be better so it will aid in the constant flogging you will be giving the engine. If not, then well use your judgment.