Oil ratio

The jet size varies the fuel - AIR ratio, not the oil ratio. OK, it may make a very marginal difference to the droplet size of the dispersed fuel in the air stream, but we're arguing about 4/5 of 5/8 of eff all to be honest.

Your carb and cylinder will be fine with the oil ratio, just concentrate on getting the air jetting right or you'll have a hole in your piston before it has a chance to seize up.

 

Ah I was reading a post that said it was bad to run a bike using pre mix because of it not getting anything while not on the throttle and I don't mean at idle I meant when riding then releasing the throttle

 

nope because the bike will still be getting fuel. generally ive found running a bike on premix it lasts longer... the only time your going to have issues is when you dont put the right amount of oil in with the petrol and dont mix it properly.

 

Wow you really don't understand what I meant lol!

 

There will be enough oil present to cope with the engine on over-run, with the throttle closed. The excess vacuum in the manifold will still pull some fuel through the idle jet of the carb until it reaches idle, so you never get no fuel at all or the engine would stall. Think about it.

 

Pre mix is a pain, until you get the habit- but it is without doubt the best and safest way to lube a scoot. Oil pumps are great for convenience- but when they fuck up, they take out everything. I had never seen an oil pump problem until this weekend - and fortunately it wasn't total catastrophic failiure.
But it is not supplying what the engine requires- and the plug told me instantly.

I should add that this is a 70 cc alu monosegment kit - the 50 ran fine. Albeit with some minor scratches. I have the same scoot and befor I removed it for safetey reasons, I never saw the like.
So i deduce that the pump has a problem - and a standard working pump would not present any problems- even with a 70 cc high end kit (like mine).
But if you are running an expensive fast spinning kit, why risk it.
Steve- what was the reason for your original question ?

 

Yeah that's what I meant but I didn't know it would pull oil through idle jet, I didn't really understand it cause my bike still runs when I'm say at 20mph and I turn it off, it slowly dies but I though it would cut out straight away

 

IT DOES NOT MATTER IF THE ENGINE IS IDLING - ON THROTTTLE OR THROTTLE BEING RELEASED. AT NO POINT IS THE ENGINE BEING STARVED OF OIL OR PETROL. A 2 STROKE ENGINE WORKS EXACTLY THE SAME ON PREMIX AS IT DOES ON AUTOLUBE. PREMIX DOES NOT DO ANY DAMAGE FULL STOP. FFS DO YOU THINK IT FULLY STOPS PUTTING FUEL AND OIL IN WHEN YOU LET THE THROTTLE OFF WHEN YOUR RUNNING AUTOLUBE? NO.

 

steve, explain your problem - and forget about lube for the moment -

 

Also, even if the throttle is closed off, the oil pump is still driven at the engine's true RPM. That means that if anything, the oil pump is over-delivering on the over-run, as there won't be so much fuel to dilute it down.

This is why two strokes smoke like buggery if you've been coasting on the over-rum for a while then crack the throttle open; you are burning off the excess oil delivered during the over-run.

Stop worrying about it, that's my advice.

 

What is the oil to fuel ratio on the standard auto lube system

 

Some of us do - it's about 3% - 33:1.

 

I was just wondering if it was better to run auto lube or pre mix with a s6 70cc street race kit, I read that it was unreliable with pre mix but obviously not, thanks for educating me anyway guys

 

about thee percent. But this is not your problem. What is tha actual symptom your scoot is suffering from?
You cannot switch from one to the other without getting dirty. So do not add fuel to your petrol (if that is what we're on about.)
I want to help - but i need some help.

 

I've just been advising Leo15 about this matter. Stage 6 say to add oil to the fuel at 60:1 and it's making his exhaust drip oil, so it's clearly too much, but Stage 6 are erring on the safe side to allow for badly adjusted oil pumps I reckon. I've told Leo15 to try premix at 100:1 in his next tankful and see if this reduces the oil dripping problem.

 

There is no problem atm but I just wanted to know what ratio the auto lube uses so I know if I need to add more oil or not when I put a 70cc kit on

 

Stage 6 seem to be aiming for 4.5% oil mix (about 20 to 25:1) and that's a LOT. You'd normally only use that much on a highly stressed racing engine, not on a road-going bike as it will smoke like ferk.

 

So that is say 100 cups of fuel to 1 cup oil?

 

Sorry I meant 1 cup 2 stroke

 

no.
look for the ratios thread, it will tell you how many ml of oil to 1l 100:1 is there.