Oiler or pre mix

[Pete]

Gidday,

Have just picked up a Yamaha PW80 for the kids. Runs well has a few battle scars and it'll probably keep me busy trying to keep it running knowing my 2 x boys.

The guy I bought it off didn't trust the "auto oil system" ( not sure how to describe it) so he ran it on a petrol / oil premix rather than adding 2 stroke oil to the reservoir and letting the oiler take care of it...

I have no problems running it this way - are his concerns valid ? How can I check the operation of the " auto oiler " ? Cause if its not working properly i guess it would be pretty fatal ! Also what would be a suitable mix ratio - my chainsaw is 50:1 where as my line trimmere is 35: 1 ?

Cheers,

Pete

[GotFlex]

my suzuki rm 125 was 32:1

[86-surf]

my little brother has a cr80 and he said his oil ratios is 25 to 1 but im not sure?

[rangimotors]

some of them had a line running from the throttle which as you wound it on more it added more oil, it was super common for them to stop working or get knocked out and the bike would go great for a few minutes and then never again. If its a bit of an old beast and ya boys are going to throw it around i think mixing it would be the way to go.
As for mix the leaner it is the faster it goes but the shorter it lasts, i would be trying 35:1 and see how it goes, if it blows heaps of blue maybe try 40:1 or 50:1 if it gets hot try 25:1 or 30:1, just have a play and see how you go. The key is short rides until you get the mix right or it'll get hot if itys too lean.

[Pete]

Gidday Rangimaotors sounds good - how will I know if its running hot ? Given that its air cooled ? Will it skmell hot or just seem hot ???

Cheers,

Pete

[rangimotors]

the old touch test of course , careful though use someone elses hand. The way to do it is to start it rich eg 30:1 and it'll probably smoke like an old dog and then lean it out slowly until its not smokey, thats the safe option but be aware that oil doesn't burn super well and if you run lots of rich gas through it it'll start filling with oil and fowling plugs etc. You could ask a bike shop, the guy you bought it off or just have a crack run it at 35:1 and see how it goes thats what i'd do anyway. I would be surprised if you had issues most can run 50:1 no problems but it depends how much jandle your giving it

[spanky]

my pw 50 says 32.1 but it is probaly a early 90s model.
vaughan

[Pete]

Thanks all,

I am going to have a look at how the oiler works and then decide whetehr to use it or just go pre mix - it'll probably be pre mix !

Cheers,

Pete

[SupraLux]

dragging up an old thread here - but it depends on the oil... mineral 2-stroke oils are generally around the 25-30:1 and synthetics are normally between 40 and 50:1 - its not so much the bike as the oil you are using that sets the ratio.

And I have never trusted in-line oilers either... if you pre-mix it then you can't go wrong... unless you assumed your dad pre-mixed it for you when he filled it with petrol on the way to where you were going to ride... then you ride it for about 10 minutes at high speed until all of the sudden the speed dies slowly and then you're sitting miles from the car with a smoking melted block of alloy in your frame Don't ask me how I know this... fortunately it was my mate and his bike and I was there to tow him back (using my trusty 4-stroke)... still, major pita

Steve