Motorized bicycle oil mixture ratios?

[Das Chicken]

I am currently running 20:1 in my 48cc two stroke, and it bogs too much under heavy throttle. I weigh only 120 lbs, and have the SBP shift kit. The oil is Penzoil semi-synthetic outboard motor oil. Any suggestions for the settings on the air/fuel mixture clip? Would it be ok to run 32:1 or 40:1 in this thing? The engine is still relatively new with about 100 miles on it.

 

[Al.Fisherman]

Re: Oil mixture ratios?

I am currently running 20:1 in my 48cc two stroke, and it bogs too much under heavy throttle. I weigh only 120 lbs, and have the SBP shift kit. The oil is Penzoil semi-synthetic outboard motor oil. Any suggestions for the settings on the air/fuel mixture clip? Would it be ok to run 32:1 or 40:1 in this thing? The engine is still relatively new with about 100 miles on it.

I use (Amsoil) DOMINATOR® Synthetic 2-Cycle @ 32:1... (3 year old build) Next mix will most likely be 50:1. There are others that run up to 100:1 depending on oil used. GET AWAY FROM OUTBOARD OIL, use oil designed for air cooled engines NOT water cooled ones.

When I built my first bike, I didnt know the difference between liquid cooled oil and air cooled oil. I was using Pennzoil marine 2 cycle oil. I didnt know about spark plug color either. That engine lasted about a year, but the rings and the crank bearings finally went. I had hoped to get more out that engine, and probably would have if I had been using the right oil and known how to adjust my air/fuel mixture. That bike is no longer with us. I am on my second bike, but my fourth engine, due to some bad luck with two other engines, not oil related. With my current engine, I started out using Lucas semi-synthetic air cooled oil, but even ordering on ebay I paid about $12 for a pint. Found universal 2 cycle synthetic oil for air cooled engines at walmart for $6, and the color of my spark plug tells me my engine is happy with it. This engine is almost a year old, and I expect to get at least another year out of it, perhaps several. If you want an air cooled 2 cycle engine to last, you need to use air cooled oil in it.

 

[rustycase]

Re: Oil mixture ratios?

There's lots of threads here on mix oil.
one thing almost for certain, 20:1 is considered by all involved to be too much oil, except for ...maybe... the very first tank of mix on a brand new engine.

Gosh, at 120lbs you should be darn near ..ing... on your motorized bicycle!
Best
rc

 

[Das Chicken]

Re: Oil mixture ratios?

There's lots of threads here on mix oil.
one thing almost for certain, 20:1 is considered by all involved to be too much oil, except for ...maybe... the very first tank of mix on a brand new engine.

Gosh, at 120lbs you should be darn near ..ing... on your motorized bicycle!
Best
rc

This would be the second tank of fuel, the first was; as the manual suggested, a ridiculous 16:1.
Well i just took it out again today. Throttle stuck once, and it died twice in about 2 miles. As for speed, well if it weren't for the excessive amount of oil, i would be able to go fast. I can cruise at 25 mph easily without using a lot of throttle, thanks to SBP's shift kit. So, about the oil, is it still able to lubricate the engine normally? Is the difference just in cooling?

 

[rustycase]

Re: Oil mixture ratios?

Well, DC, what we can buy at most any autoparts store is superior in all qualities you may consider, than anything ever available in the past, that was pumped from the ground and distilled.

We may have some petroleum physicists here on the motorbicycling.com forum who can explain the distinct benefits of synthesized long chain complex hydrocarbons, but it's certainly not me!

In general, the membership here all seem quite pleased with the performance of their lubricating oil. There's actually NOT a lot of grumbling about fouled plugs and extensive carbon deposits which had been recurring complaints in the old days.

Mixed properly, the new oils burn cleaner, lubricate the internal parts better, and because of the preceeding, the engine will operate cooler, and live longer.

It's a win-win situation!

Yay!


Best
rc

..U would do well to review the threads on re-jetting your carburetor.
pretty good chance your engine is bogging because the jet is incorrect.
.

 

[Rocky_Motor]

Re: Oil mixture ratios?

I use tanaka 2 stroke oil. 24:1 for the first few tanks. I now use it 32-40. The bottle suggests 50:1 but I'm not sure with these engines. I'm sure it would work fine though, I may move to it or close to it in the future.
Use a quality 2 stroke oil. It's dumb to skimp out on proper lubrication

 

[Len455]

Re: Oil mixture ratios?

I have a new kit to with about 75 miles and i had the same thing to. I thought it was running to rich so i moved the clip up and it was still bogging. I finaly realized it was bogging because it wasnt getting enough gas! I moved the clip down to the middle and damn it moves! I weigh the same as you and running the same oil mix btw. Just an idea if your confused like me.