100:1 Mix

Can not say I have experience with opti. As for sabre. I've been running 100:1 in 35 stihl 4mix blowers and whackers. As for lube related failures only 2 seized at the wrist pin this season when I tear them Down plenty of oil in low end. As for carbon buildup wohhhh no good even at that ratio I'm still tearing them Down every 3 mo... they basically run wide open 8hrs a day tho the carbon holds the valves open.
 
"they basically run wide open 8hrs a day tho the carbon holds the valves open."

2 stroke engines don't have valves. Are you sure that's your problem?
This thread is about using an oil mixed @ 100:1 in 2 stroke engines.


I'm going to sum up this thread by saying this: Try it. If you don't like it use what you want. If you've never tried it you can't have an opinion. If you've tried it and found it everything it is advertised as being, good for you. Join the club. If you've never tried it and are curious, try it and decide for yourself.

This senseless bickering over if it works or not is fruitless and silly. Everyone must decide for themselves if an oil made to run at 100:1 is right for them. Most of those who have tried it have found it is all it is cracked up to be. Those who have negative opinions are usually those who have never tried it and are relying on old, well established rules of 2 stroke lubrication requirements. To them I say, use what works for you and that you're comfortable with. No one is forcing Opti-2 or any other brand of oil on you. Just don't tell those who have used and are satisfied with it that they are wrong.

Tom
 
This senseless bickering over if it works or not is fruitless and silly.


2 door ..... the sensless bickering is all the fun LOL ! srs....

if it were not for a milion pages of sensless bickering ...... i would not have tried it.

only been running 100:1 for 2 days and all i can say so far is that i have some minor four stroking now all across the carbs range, a veryy little off idle to 1/4, some from 1/2 to 3/4, and a lot at WOT... seems like the more the venturi opens the more it four strokes, seems like new jets are i order, i am running a 70 so i will start by gong down one size on the main and retunning the air fuel mix screw. should clear up a lot of it, i dont think its so bad i need to go down more than2 jet sizes or have to change out pilot jets.

as for preformance ..... eeeerrrrr welll i cant tell yet its not tunned propperly anymore, but it feels like it will have a bit more throttle responce once it is tunned..... i just get that feeling from the way its running now, also with smaller jets i expect slightly better gas milage, i havent put enough miles o it for a tear down and its not tunned. but once its dialed in and i put a few hundred miles on it, i plan to tear it down and take some photos for you all and for my self to show how well this oil does in a high comp modded motor that gets beat on at high rpms.
 
rog, u r 4 stroking now because it is running too rich!
...crazy, I know!

with less mix oil, there is too much fuel!
...the mix oil is not considered to be part of the fuel component...

so now you get to go through the process of leaning it out a bit! :-)

...That taco Stihl sure does bring up a number of thoughts...
It gets rid of the oil sump, which is probably a good idea in a hand tool ... and it's probably better than splash lubrication???

..lots to think about...
It would be nice to see some -open source- insight into the Stihl engineers having discussion on that one!

Like... would giving up one of the power strokes be SO beneficial for a clean burn to make it worth while??? and why not a valved two smoke???

I dunno...

Best
rc
 
2 cycle oil Tom, amsoil sabre 100;1 I want to get a br600 still motor it's 4.5hp probably get it on a bike easy ..
 
2 cycle oil Tom, amsoil sabre 100;1 I want to get a br600 still motor it's 4.5hp probably get it on a bike easy ..
Mounting position wouldn't be an issue if I understand the concept. No sump, no worrys about keeping oil in. That would give you the option of slanting the cylinder toward the front instead of backwards like some of the 4 strokes currently popular. Would certainly improve the aesthetics.
Keep us posted if you mount one on a bike. Interesting.

Tom
 
Installed a Dax balanced lower / 69cc top end / slant head today. Running Opti 2 @ 80-1 for the 1st 1/2 gallon because I'm not macho enough to go w/ 100-1 from the get-go. Anyway, this thing is smooth and crazy-fast!

I just ordered a Dax Type D F-80 balanced low end
this past Friday Dec. 26th W/$ I got from Christmas lottery tickets!!! Cha ching & I cant wait for it to get here! dance1
 
I just ordered a Dax Type D F-80 balanced low end
this past Friday Dec. 26th W/$ I got from Christmas lottery tickets!!! Cha ching & I cant wait for it to get here! dance1

Thats great......! You'll enjoy it when you get it built up and going, I know I sure like mine, got two more that Im anxious to get together when I can, some good port work and you'll be impressed how good and how much smoother it runs if it's anything like mine, it aint butter smooth but much smoother at high rpms than any of the other china girl engine I have or have had.

I started mine off on 100:1 mix Opti2 and with a bit over 200 hard fast high revving miles on it now it's still running great.
Best wishes jumpa.....

Map
(^)
 
Just a word of warning. Dax, Duane, will not warranty your engine if he knows you run Opti-2 @ 100:1. Him and I have had many discussions about this and he stands by his opinion that 100:1 isn't enough oil. I've countered his contention with no less that five engines I've bought from him, all with several hundred or over a thousand miles on them and still running perfect using only Opti from break in to present.
If in doubt, ask first.
To be totally accurate Duane and I have not talked about this for a while. He might have changed his mind since then.

We used to have a running joke. He would tell me that I was going to blow up my engine and I would say, "That's okay. I'm friends with the guy who sold it to me." :)

Tom
 
I've been using Opti-2 for 2 years now. Got a big pack of packets, a lifetime supply.

Not at 100:1, only have a 1 gallon can, so 70:1. I like the packets, just nip off the corner and squeeze into the can. No measuring, no need to wipe out old dusty measuring cups, just nip and squeeze. Easy.
 
What size packets for the 1 Gal of Gas ? 1.8oz or 3.2oz I get the 3oz's for $2.oo and the 1oz's for a $1.oo at a little small engine repair shop at the other end of the city.

I am currently trying to get the guy to sell me a re-built 5 hp exposed push rod Briggs & Stratton, he re-built it several years ago and then stuck it on a back shelf and accumulated out from that point with other stuff.
 
I use OPTI-2 (1.8 Oz@gallon) and runs great and i dont have oil dripping out my pipe anymore. Plug is good so far. Still need to do some tuning though. I need to do some mods to adjust my powerband to my riding style. cylender, head & piston and I want to go to a 68 jet
 
Do you have a NT carb? After running Opti at 100:1 mine was 4 stroking a lot with the stock jet, I installed a 68 and it improved it the issue slightly, then I switched to a 66 and it runs way better with just a bit of 4 stroking at about 1/3 throttle and again at about 2/3. I may order an even smaller jet to see if that will eliminate the issue altogether.
 
Do you have a NT carb? After running Opti at 100:1 mine was 4 stroking a lot with the stock jet, I installed a 68 and it improved it the issue slightly, then I switched to a 66 and it runs way better with just a bit of 4 stroking at about 1/3 throttle and again at about 2/3. I may order an even smaller jet to see if that will eliminate the issue altogether.

running a 16mm yamaha y zinnger / pw80 carb, #70 main jet, i just got my 90deg angle air filter though so now i can tune it up. i was running a brigs and straton lawn mower filter adapted to the carb with a spacer, now that i have a proper high flow filter i can tune it with my jet kit.

on another note on the 90 deg air filter from SBP.... if you use that filter angled upwards, it keeps your filter cleaner, this is due to the blowback from the motor hitting the rubber angle instead of the filter paper ! i like it a lot !
 
Anytime you reduce the oil content in your fuel mix you have to understand that you are effectively increasing the fuel portion of that mix, or making it richer. The oil is not considered a combustable so therefore when you reduce the ratio you must decrease the fuel to air ratio at the same time.

This is where those who are against 100:1 mixes feel you can do damage to your engine. You must lean out the mix (less fuel to air) to get proper combustion. Reducing jet size is the best way to accomplish this. The naysayers will tell you that leaning that much will cause problems such as overheating, pre-ignition, piston or cylinder wall or bearing damage. What they don't understand is that even with the 100:1 fuel/oil mix, the lubrication is still there. It just doesn't take as much (quantity) as if using standard 2stroke oil.

I don't use jet sizes, 66, 68, etc. I find them too nebulous. I solder and re-drill stock jets until I get a good clean 2 stroke under load and good spark plug color. I've overshot and found my engines running lean at top end. That's when I come back and drill them out one drill size larger, or whatever it requires for best running condition.

With the NT carburetor you can adjust mid range (up to 3/4 throttle) with the 'C' clip and needle but WOT performance requires you to do some experimenting with jet size.

Your altitude above sea level will also have an effect on tuning. The higher you are, the leaner you need to go. The closer to sea level you are the richer you can run the fuel/air mix.

In short: If you plan to run Opti-2, or any oil at 100:1 you'll need to start experimenting with jet size and go leaner with your fuel/air mix for best performance.

Tom
 
Yes i have a stock NT on mine. I have the same 4 stroking problem but eventually i will go to a reed valve and a different carb I have been ordering my parts piece by piece
 
Yes i have a stock NT on mine. I have the same 4 stroking problem but eventually i will go to a reed valve and a different carb I have been ordering my parts piece by piece

My suggestion is don't waiste your money on the reed valve stuff, just tune the carb to run correctly as Tom has given advise on in his post and you will have a nice running engine if your ports are deburred and matched up pretty good and the engine doesn't have really crazy bad upper rpm vibes from a badly balanced crank, a free flowing exhaust is a must of these china girl engines for top performance also, a stock unmodified pipe is a performance killerrrrrr.... on these engines.

The RT carb from thatsdax is also a good option that wont do better on the top end than the NT in my experience but will offer better low to mid throttle response and is also easy to tune by just changing main jet size.

map
(^)
 
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