Gas/oil mix ratio

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cartisdm

New Member
Oct 8, 2008
42
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Harrisonburg, VA
I'm a little confused on what oil mixture to use after break in. Forum member deacon and a few other places have suggested a 32:1 but most places I see, say a ratio of 16:1.

A lot of things people do are just out of preference, but those are two opposites ends of the spectrum. Which one is correct?

I'm using 20:1 right now, but once I get my engine broken in I'll need to switch.
 

NunyaBidness

Active Member
Jun 29, 2008
1,062
2
38
memphis tn
I've never measured an exact amount I just pore gas in and add a lil 2-stroke oil.
most people around here will say 32:1 and that's about what I try to guesstimate with my mix.
 

Finfan

New Member
Aug 29, 2008
871
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Tucson, AZ USA
My understanding is that the 16:1 number comes from the days of using regular 30 weight automotive oil in the mix. Which might still be the practice in China. Using 2-cycle oil the recommended starting mixture is 20:1. Where you go from there depends on who you talk to. Everybody seems to have their own idea of the best mix. There is also debate over using synthetic vs. fossil oil for break in. There seems to be a belief that using fossil oil will cause the engine to wear in better/faster. I am still in the break in phase so I am using 20:1 Valvoline. I haven't decided yet where to go from there. Good luck!
 

cartisdm

New Member
Oct 8, 2008
42
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Harrisonburg, VA
Well ignoring the chinese directions won't be a problem for me, they were pretty much useless/wrong anyway so it doesn't surprise me they would be outdated on an oil mixture.

I just started the engine up for the first time on Saturday so I have plenty of break-in left. After that I guess I'll just mix up some 32:1
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
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up north now
A note to clear some things up-
Too much oil will cause carbon build up fairly quickly IF YOU USE NON-SYNTHETIC OIL.
The directions say 16 or 20 to one as stated above because that would be using automotive 30 wt. from the 60's.... The newer oils are far and away better than anything from even 10 years ago.

40 or 50 to 1 may be to lean even with good synthetic due to horrible loose/uneven tolerances in the wristpin and bottom end.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I have one engine with 800+ miles on it and I broke it in with 40:1 Valvoline standard 2 stroke oil and then I've run about 60:1 mix of Opti 2 mostly since and I have took it on several 15-20 mile trips and ran it almost full throttle the entire way without ever having an issue and it still runes great.

I have another one that I ran semi sunthetic in for about the first 50-75 miles and now it is on Opti 2 @ 60:1 and it runs like a champ.

just about any oil will work and I have used several in many 2 smokers but I will have to say that the Opti 2 has proven itself to me to be one of the best out there IMO, very little smoke, runs very clean in the engine and because of the small amount needed it is very economical to use.......so from a 1 to 10 rating I'll give it a 10+.

In a not so tight tolerance engine the quality of the oil is more important than the quantity IMO, oil mixed with fuel offers very little cushion but having a very high film strength highly lubricating oil will fair much better for making an engine last than a thicker coating of lesser quality lubricant, thats why some of the newest and most powerful modern engine use engine oils like 0w - 20w Synthetics instead of the 20W - 50W oil that was used a few years ago in manny HO engines, high quality lube doesnt have to be thick, its all about film strength and how the oil acts in extreme heat & pressure conditions, and that is why oils like Opti 2 are actually much better than any of the conventional oils and this has been proven over & over.....

I say break in just the way you have been at 32:1 and then after 100miles or so get soem quality Synthetic oil and lean the mixer to a point you feel comfortable and enjoy good engine life and have fun.....this is my opinion nothing more nothing less so please no one come unglued thinking I'm bashing conventional oils, I'm not just truthfully stating some facts about the synthetics advantages proven by science an trial not just my opinion...

Peace :-}
 

Dogtown Burner

New Member
Sep 15, 2011
349
3
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Los Angeles
A note to clear some things up-
Too much oil will cause carbon build up fairly quickly IF YOU USE NON-SYNTHETIC OIL.
The directions say 16 or 20 to one as stated above because that would be using automotive 30 wt. from the 60's.... The newer oils are far and away better than anything from even 10 years ago.

40 or 50 to 1 may be to lean even with good synthetic due to horrible loose/uneven tolerances in the wristpin and bottom end.
ok Joe- you jumped from 16:1 in the '60's to "50:1 may be too lean". is there a middle ground somewhere in your theory?
 

Greybeard

New Member
Feb 8, 2011
336
1
0
Sequim WA
I talked to a small engine repairman this morning about this very subject. He sells synthetics including Opti, and said he'd never run one with less than a 32-1. His logic: Tearing down or throwing away an engine cost a lot more than changing a spark plug more often, or cleaning out a muffler.
I asked because in checking out the Tanaka 32cc, it said to run it at 50-1, including break in. He said they had a cat in the muffler, and to get it approved for emissions, they had to spec it at 50-1.
 

Dogtown Burner

New Member
Sep 15, 2011
349
3
0
Los Angeles
Got the krank sleigh running today. Not sure what the maker is, but is a center plug 66cc with the weird exhaust and blue case stickers. Carb has Chinese markings and non adjustable main jet. After an unplugged cdi wire, a leaky fuel hose, grenaded rear coaster, and a broken chain, she runs! At first very low and few pops. As it warmed up it got brighter and more lively. Then i started loading the piston on a slight grade. Runs strong and smooth with 20:1 mixture dino juice. Sure ain't a CR 250, but it at least runs smooth and pulls steady with no bogging or detonation. Plug is a nice light brown but I now understand the quest for more power on the forum. Norm thinks it's a grubee. I bought it from eBay. Cheap but Way nicer presentation than the raw engine package I'm using on the mustang. This even came with directions! Lol.