Fuel-oil premix ratio

[SRAD]

Fuel-oil premix ratio effect

I was thinking for 2 stroke, does lean mixture of fuel-oil ex.(18:1 or less) can affect something else beside throttle response and fouled spark plug if driving slow.
Oil is lubricating piston, rod, crankshaft and bearings but can lean fuel mixture affect less cooling of piston crown because fuel also has some effect for cooling?
I am asking all this because I worked on some 2 stroke machines that were driven hard and with stock oil pump setup, internal parts werent oiled well and it looked more dry than some of my bikes which were driven very hard but with oil pump set to maximum and some premix in reservoir which makes fuel-oil mix less than 20:1 and when I drive hard I dont have any problems.

Sometimes I know to ride whole hour with very hi revs on open twisty road and I am scared that it is not well lubricated in that condition, so is there anything bad if I mix it about 18:1 when i ride really hard? The engine is Rotax 122 (Aprilia MX 125)

Thanks

 

[SRAD]

I changed the text to make it more simple because first post was complicated.

Sorry :worship:

SRAD

 

[Rich Rohrich]

so is there anything bad if I mix it about 18:1 when i ride really hard? The engine is Rotax 122 (Aprilia MX 125)

As long as you jet it correctly and use an oil that is designed to run at 18:1 it won't cause any problems.

Here's what a BR9EVX plug looks like from my CR125 with nearly perfect jetting for MX. The fuel is Phillips B35 unleaded, oil is Phillips Xamax mixed at 18:1 ratio. The bike had incredibly good throttle response with this combination.

 

[SRAD]

Thanks on replay, the bike is full stock and it acts great. I run it on eurosuper 98 gas and total 2t full syntheticts injected on max setup oil pump and some total 2t semi synthetics premix. So ratio is maybe 17:1 - 15:1 and it is great on stock NGK BR10 EG.