Two Stroke Initial Pre-Mix Question

[Wyvern]

I did 1/2 gallon 20:1, and since moved to 30:1 and will probably stay there.

 

[Fly1]

Let me see if I can help you. I go back many years in two stroke racing engines most noted kart racing.
Racing karts are very high rpm engines, so they require more oil, anywhere from 20 to 1 to 16 to1. It all
Comes to RPM in a nut shell as far as lubrication.

The average kart engine running a slipper clutch runs
12000 to 14000 RPM. Those engines run 20 to 1, but the direct drive engines with out a slip clutch run on
up to 18000 to 20000 rpm’s. They require 16 to 1.

Now that is extreem rpm’s for any two stroke engine.
But on the other end of the spectrum outboard boat engines only run 5500 to 6000 RPM. So they can
get by running 50 to 1, plus there water cooled .

These little engines can very from 5000 to maybe 8000 depending modified with expansion chamber. So let’s make it simple across the board for you.

If your Motor bike is stock, I would recommend 40 to 1, if modified slightly go 32 to 1. Remember a little more
oil never hurts, in fact it can help by sealing your rings better.

We found on our dyno with kart racing we got a little more power with a little more oil up to a point. Now don,t let the know it all bunch come on about failing your spark plug crap.

The more oil is not what makes your engine fail plugs, it is your carb is running to rich, Why the more oil you add to the fuel the higher the viscosity of the fuel. The thicker fuel the more you must richen the carb. Just do not go to much, that’s what fails plugs. I even run my 225 hp Mercury bass boat motor on 40 to one. Yes it smokes a little more at idle but when I open her up no smoke
and I know I’m, not going to stick a piston. One more thing, ( I have never failed a spark plug in my boat motor) !

Hope this helps Fly

 

[rawly old]

A point of confusion for me, that hopefully can be clarified.
I have never run one of the Chinese "C/G" motors. About 20+ years back I did buy one. When it arrived I opened the box, looked it over, re-boxed it and put it on Craigs list.
So that is the extent of my familiarity with those.
I only mention this because a large percentage of the posts on this forum relate to Chinese motors. And I'm supposing that the answer to my question might be based on those.
So..I have read several posts that say never use Full Synthetic pre mix for initial run in. And I have read posts that mention initial mix ratios from 16:1 up to 20:1.
I get it, first start up and first hours of service require all the lubrication they can get.
Which brings me to my question, why hobble the lubrication by only using mineral based pre mix's and crutching it with high oil mix ratios? Why not just start out with a better synthetic oil and mix it at 24:1 or 32:1 ?
I have been an engine builder for over 60 yr's. And I know how critical start up and initial run in lubrication is. So why not use the best available? rather than hope for the best
I personally have used full synthetic in all new engines since the early 1970's and never had a problem with rings seating, bearing failures, or piston seizing.
So, is the higher mix ratio of a lesser oil just something that applies to the Chinese 2 stroke motors?
Thanks

I just cleaned up my old Tanaka 4210 Pure fire, 50:1, with a new plug, tubing, & fuel filter, cleanest 2 stroke ever made.
It came with a 7 year warranty for private use. You can't buy one fur love nor money, Cost too much to manufacture,
samurai stainless cylinder. it was running before that, outa run better now. They could hit 11k rpm static unloaded,
but mine's governed to 9k. Ain't no 4 stroke 50cc gonna do 11. & mine's 39cc. I onest used ether to start a sooby;
it mighta hit 11k for half a second before it blew up.

 

[Fly1]

God I try, but this is why I quit trying to help fools. There is a old saying ignorance can be fixed, (just not knowing)!
But stupid is for ever! (Knowing it all no matter who is trying to help! ) I gave up years ago. I just thought I would test
the waters one final time. At 78 years old, & spending my whole life building racing & testing two stroke engines of
every kind I gave up trying. Not another reply from me. Fly

 

[robe]

Oil is cheap insurance. Why cheap out?

 

[DAMIEN1307]

Oil is cheap insurance. Why cheap out?

Exactly right.

 

[fivestar45]

Wait a minute.
Oil is cheap insurance. Why cheap out?
Exactly right.
When I brought up using the best oil available, the general reply was that it's not good for break in with these motors. They need high ratios of cheap oil.
How does that fit in with "Why Cheap Out" & "Exactly Right" ?

 

[DAMIEN1307]

When I brought up using the best oil available, the general reply was that it's not good for break in with these motors. They need high ratios of cheap oil.

Wait a minute.
Oil is cheap insurance. Why cheap out?
Exactly right.

When I brought up using the best oil available, the general reply was that it's not good for break in with these motors. They need high ratios of cheap oil.
How does that fit in with "Why Cheap Out" & "Exactly Right" ?

When we were talking to you it was about breakiin oil and then using synthetics AFTER breakin...We were NOT talking about high or low QUALITY of oil in these postings your pointing at.

We are talking about not cheapening out on QUANTITY of oil so as not to burn out motors.

What we are NOW just discussing is QUANTITY of oil being use...Oil/gas ratio...TOTALLY different thing.

Reading is fundamental, go back and re-read it where we are talking ratio's, QUANTITY, NOT QUALITY in THIS particular case.

This has nothing to do with so-called "BEST OIL"...Which by the way, no such thing as the very best.

I really start getting very pissed off about this stupid "Best Oil" crap that keeps coming up.

If you read this thread below, you will note exactly how pissed I get about the abject stupidty of people blindly following brand loyalties and saying this is best or that is best with zero lab analysis reports to back up their BS.

READ not just this post below, but the entire thread ...This is the guy you can blame for my lack of tolerance on this subject...Oh, that's right, you can't...He's been deleted...Some dogs just refuse to let go of the bone.

OK, Let's Get Crazy About 2 Stroke Racing Oils

Here we go: This discussion is relevant for performance above 10,000 rpm or for engines that tend to overheat. Such a user needs high temperature resistance, and this is nomally reflected in the flash point of the oil, which is found in the Materials Safety Data Sheet (MSDS). The flash point is...

motoredbikes.com

 

[GW's Motorized]

Reading is fundamental

Finally, I'm not the target of Uncle Damien's wrath lol

 

[DAMIEN1307]

Finally, I'm not the target of Uncle Damien's wrath lol

I've never been wrathful with ya Gordy...lol.