Why the 25:1 fuel - oil ratio for our engines?

[MonsterAir]

It would be cool if BuzzKill ever finishes his dyno! Then we could have him test top rpm with each mixture!

 

[Troopermaniac]

It would be cool if BuzzKill ever finishes his dyno! Then we could have him test top rpm with each mixture!

This has been tested before though. You do get more RPM with less oil.

 

[MonsterAir]

Yes I know (hence why I run 32:1) but how much and I want to see it on vid!

 

[Seandonato73]

This has been a raging debate on every 2 stroke engine forum since engine oil stopped being used as premix oil. High oil ratios arnt needed for the average user. Racing and peak performance are a different story, and not a boat most of us are in. Again run whatever ratio you want, with whatever oil you like. At the end of the day it's really a moot point.

 

[Dashz]

Roger guys, thanks for the feedback.
Ill run 40:1 to trigger the “twenty five oners” ?
Biggest issue for me was carbon build up tbh, with higher ratio the engine runs cleaner. I asked my father and he has been using a 25cc weedwacker for the last 15 years on 50:1 ?
It does indeed come down to preference, to whatever makes you feel comfortable.

 

[MonsterAir]

Your using crap oil if your seeing carbon on piston. Use a quality castor oil like Castor927

 

[Rep732]

I have a slight build up using castor 927 but im sure the ratio contributes to it. Id say its more like a tar build up rather than ash

 

[Z.hb71]

I have pretty much zero buildup with castor 927 and 28:1. Just gotta know how to tune

 

[Rep732]

Im at 25:1 and your at 28:1 how is that tuning related Z

 

[Z.hb71]

Im at 25:1 and your at 28:1 how is that tuning related Z

Wasn't replying to your comment and wasn't a jab at you, was just stating what I run. And carbon build up is kinda tune related, if you are running it really damn rich you will have more buildup then when it is tuned properly.

 

[Seandonato73]

Yeah, no unless your pig rich the oil will do what the oil does, it isnt fuel and typically doesn't give a complete burn, hence carbon build up. Caster will give a different type if build up as well, kinda a yellow hard coating after extensive running, it doesn't contain the dispersants or detergents of modern oils. The additive package and base stock is what separates the different oils. Castor is an excellent lubricant, but typically falls on its arse with the additive package, and low temp drop out. Does this make it a bad oil? Heck no, just something that happens.

 

[Rep732]

Sean you hit the nail on the head with that. The plug looks great and the face of the piston has maybe the size smaller than a penny with the dark yellowish color definitely indicates excess oil

 

[evssv]

After everything Sean said I run 28:1 per OBR.

sn me on my 4x engines....?....

 

[Dashz]

Guys I found the official info from Zenoah, guess what they say...
“• Mix gasoline (octane over 95) and high grade 2 cycle engine oil (mixing use type; JASO FC grade or ISO-L-EGC grade) at mixing ratio 25~40:1.”
Zenoah 24-26-29cc
A proclaimed tide for the 25ers , 32ers and 40ers. Sorry for the 20 and 50 guys you didnt win.

 

[Rep732]

Up to 40:1 im not nervous anymore

One issue I don't have easy access to 95+ octane

 

[Z.hb71]

Are we done with this topic now ??

 

[MonsterAir]

I'm sure you have somewhere near you that sells octane booster.

 

[Seandonato73]

Depends if they are using the us method or the Ron? Method the two different methods come up with different ratings.

 

[TODD]

Usually seems to be about 2 or 3 points difference if I remember right on the rating. With the USA
being the lower of the numbers.

 

[21bangbang]

Im in the 25/1 is silly camp. The only thing it seems to accomplish is a shitload of sludge coming out the pipe, and way more deposits on the internals. Im yet to burn up a single engine and have a few with well over 10 gallons through them. My CY23cc is probably closer to 20 gal and worked fine when I pulled it.