Perhaps i am missinformed, or didnt explain what i thought i knew, very well.
A lot of japanese carby cars were built to run on 89ron fuel. My pulsar and rodeo before it.
I thought that must have been the fuel they had there. I stand corrected.
On the victa oil ratio.
Applies to all 2 strokes running premix. Its a black art.
You have a container of fuel with oil in it.
You put some in the tank.
As the fuel goes into the engine it is metered by the jet in the carburettor. The oil in the fuel is part of this metered amount and is non combustable. (it does burn eventually but it is not the fuel that makes the big bangs) If you alter the ratio you are effecting the amount of fuel that is passing through the jet (because oil replaces it). So essentially you can alter the engines jetting by altering the premix ratio.
To burn off the oil the engine needs to be in good condition and running at a hot enough temprature. Poor compression and the engine will smoke. Engine running too rich (not enough oil) and it will smoke as the combustion temps are too low.
Engine running too lean (too much oil) and it could seize or melt a hole in the piston as the temps are too high.
I do not know how it works on a Victa etc. But on a motorbike the way to tell if the oil to fuel ratio is correct is too run the motor long and hard then pull it down and measure the depth of the pool of 2 stroke oil in the bottom of the crankcase. Hardly practical.
The rule of thumb is that the harder it revs the more oil that should be in the mix. 500cc single 50 or more to one. 125ccs 32:1. Ive owned quite a few 200cc two strokes and run all of them on 32:1 and never had an issue. But they have been jetted correctly to suit Vortex98 and the Shell Advance oil that i had and that was the only mix run in it.
The important thing is the correct jetting, the RON of the fuel, the type of oil and the ratio its mixed at are secondry factors.
New Yamaha YZ250 2t were still reccomended as 16 or 18 to one. That was 2 years ago.
Given that the Victa has a rev celing of under 4000rpm and most bikes will easy see over 6000 some as far as 10000rpm, you could say that the Victa is over oiled.
But if you drop the oil ratio the motor would be running rich.
It would be a great thing if you could get a series of sized jets for a victa. But for what it is and what it does it hardly seems practical.
In theory you could run a victa on 100:1 and it would do in no harm.
In practice im sure some Victas get run on 10:1 mix where the fuel has been left sit and the fuel has evapourated out.
Makes one wish for the days of the BP Zoom drum over again. Makes life pretty simple. Its surprising how many people are anti mixing fuel. Its not that hard, i dont see what the issue is.
