[bigdev]

Hello all new to the forum..

Question ?

I have a 1983 Yamaha 25hp 2 stroke, I have read on other forums that you need to change the oil mixture as the engine gets older ?
So i use 100/1 mixture at the moment do i have to change to 50/1 mixture..as the engine is so old.

thank for any help
BD

[JUSTINTIME]

go 50 to 1

[bigdev]

Cheers m8 for the info...but i have just read on another forum that if i drop it to 50/1 that the engine will smoke alot more...

[rajabatis]

Originally Posted by JUSTINTIME

go 50 to 1

Why?

[deejaycee_2000]

50:1 is the proper mixture for your motor, a motor would smoke the older it gets anyway, just like an old car, as wear and tear start to happen, but the fact remains that it needs it's oil ..... so go 50:1

[bigdev]

I took this reply from another forum ! ref the above question....
Here goes???????????? as it is confusing me big time..is it 100/1 or 50/1.?

so how does that work then if its an autolube yamaha?? have the whole oiling system recalibrated after 12 months. I'd be very very cautious. changing from 100:1 to 50:1 after 12 months will defiantely damage one thing - a 2 year or longer warranty

I've ran out of petrol on my yam and plugged a tank of 50:1 and it was far from happy. Do it for a long period your going to gum up lots of things that weren't designed for that much oil, the gumming will settle behing piston rings forcing them eventually to stick for one thing. The reed valves will glaze and gum up and not work effectively starving the engine of even more fuel

If I were a cynical person (!) it might be a good idea for "pro's" to advise this, potentially more engines to fix! Ask them to put it in writing, especially if they are an authorised dealer/service centre...

[JUSTINTIME]

matters what oil to use
the auto blend is 100/1 at idle then switches over to 50/1 at wot
there is the oil pump that connects to the throttle linkage that monitors the throttle opening
the more it opens the more oil

do what u want