Two Stroke Initial Pre-Mix Question

[fivestar45]

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

 

[Risk Man]

I don't have the answer as I am only three engines (china girls) in on this, but can you compare the components of your large engine experience with what you see and know about the "Chinesium" metal and components with these engines and conclude that they need special handling / lubrication in order to make them viable?

 

[Chainlube]

With very loose tolerances full synthetic is too slick for proper seating of the rings. These little engines get all their lubrication from the premix, so if the rings brush it all away they might take a bit of the cylinder lining with it, and bit by bit the whole cylinder fails. Once the rings have had a chance to beat a path, then they are less likely to damage the lining.

 

[fivestar45]

Well it sounds like these motors have a need for even better lubrication than some others. So my question stands, why use more of a less capable lubricant than use a superior lubricant to start with?

 

[DAMIEN1307]

why use more of a less capable lubricant than use a superior lubricant to start with?

He already answered that in his reply to you.

full synthetic is too slick for proper seating of the rings.

 

[DAMIEN1307]

Well it sounds like these motors have a need for even better lubrication than some others. So my question stands, why use more of a less capable lubricant than use a superior lubricant to start with?

Use a good quality low or no ash 2 cycle conventional oil for breakin such as the one I always use for breakin...Valvoline 2 cycle multi-purpose conventional oil...After breakin, I always use Amsoil Dominator full synthetic 2 cycle oil.

 

[fivestar45]

I don't have the answer as I am only three engines (china girls) in on this, but can you compare the components of your large engine experience with what you see and know about the "Chinesium" metal and components with these engines and conclude that they need special handling / lubrication in order to make them viable?

Well, I'm not directly comparing these Chinese motors to automotive motors.
I am trying to align them with other small bore motors. I've had great reliability using synthetic pre-mix starting around late 1969 with Hodaka 90's and 100, and later the 125's. At that time we used Golden Spectro at around 40:1 and could run them lean with no piston seizures. That continued into the 1970"s with Yamaha's, Kawasaki's, and Honda's. After that all of the four stroke bike engine builds got full syn from the get go.
And I believe now there are mfg's recommending synthetic pre mix for new bikes.

 

[DAMIEN1307]

Well, I'm not directly comparing these Chinese motors to automotive motors.
I am trying to align them with other small bore motors. I've had great reliability using synthetic pre-mix starting around late 1969 with Hodaka 90's and 100, and later the 125's. At that time we used Golden Spectro at around 40:1 and could run them lean with no piston seizures. That continued into the 1970"s with Yamaha's, Kawasaki's, and Honda's. After that all of the four stroke bike engine builds got full syn from the get go.
And I believe now there are mfg's recommending synthetic pre mix for new bikes.

Those bikes and motors you speak of are made to a much higher standard than these little China Girl motors...Dont treat these Chinesium motors like you would higher quality motors, these things are quit contankerous if you don't treat them the way they need to right from the beginning...lol.

 

[fivestar45]

He already answered that in his reply to you.

O K so that's why the super rich mineral oil mix? So the rings will seat?
If ring seating is a problem, why not run a leaner ratio with synthetic?
Is the issue basically a Chinese motor issue in that their rings will not seat with good lubrication?

 

[DAMIEN1307]

why not run a leaner ratio with synthetic?

If you do that, you will usually do damage to the cylinder walls and possibly melt down the Chinesium aluminum piston.

After being an ASE certified mechanic for over 20 years, after leaving police work, everything I learned from the usual norms of automotive mechanics needed to be basically thrown out the window when dealing with these cheaply made Chinesium motors.

As a fair comparison, it's like trying to compare a BMW or Mercedes Benz or a Maybach with its superior German engineering with a Yugo...lol.