two stroke mix questions

[motorbyclist]

So tonight i got my 50cc 2-smoke air cooled chinese pocket rocket running after a long period of it refusing to start and my refusing to fix it.

now it's running it seems to me the fuel mix was the source of my problems gumming everything up with oil, and being the typical 4-stroke kinda guy i am i'm unsure what would be the right way to go about it....

i hear running more oil gives better power, but i reckon that's what stuffed up my bike (dunno what i was running when she died)

would more oil make her run lean and overheat? or would more oil just bog everything down but keep it cool?

the manual says to run 25:1 for the first 5 tanks and 50:1 from then on - i should be past those 5 tanks by now, but with such a range available do i have much leeway? would it be wise to run 40:1 or what?

cheers

(surprisingly my quick search of the forum didn't give a solid answer for my questions)

[k14]

Running more oil would tend to make the bike run lean. For example if you take a litre of fuel mix made up, one with a higher oil mix ration than the other, any set amount of fuel mix will have more oil in it. Thus will have less petrol and thus make your bike run leaner. This should prob make a bit more power but not knowing how highly strung these bikes are I would probably err on the side of caution.

If you go to 40:1 it is richer than 25:1 and since you have already gone through a few tanks the bottom end etc will be run in properly. I'd say they have a bit of leway but just to be safe. Then maybe you could go up to 45:1 and then 50:1?

[Guided_monkey]

Lets start at the beginning....... the oil in the mixture is primarily there to lubricate the conrod bearings (big end and pinnion).

Unlike a 4 stroke the gearbox oil is only for the gearbox.

If there is a lack of oil (say 100:1) then expect a big end bearing failure. It used to happen on the 80/90's 2 strokes when the oil pump would fail.

If on the other hand there is too much oil (10:1) then the sparkplug will have a shortened life. Sparkplugs on 2 strokes are only good for approx. 5 000 kms before they are nackered. They work harder as they'regetting not only atomised fuel but oil as well.

Ensure that good quality motorbike 2 srtoke oil is used.

Go with the manufacturers recommendations (50:1) and keep an eye on the condition of the plug. This will give you a good idea on how well the engine is running.

Any further q's PM me.

[motorbyclist]

yea experimenting today and talking to my uncle i'm going to run on 50:1

thanks guys