Repair Help Needed Please

Rudy

New Member
I just purchased a used 80cc motorized bike a few days ago and it runs smooth - rough - smooth - rough day to day, on and off. Can anybody suggest a remedy? Thanks!

scratg
 
Try a fresh mix of gas....40:1.
Look at the plug...is it black and oily? Grey or brown? White?
 
Is the proper oil to gas mix 40 to 1 or 50 to 1?

I'll have to look at the plug tomorrow.

Thanks so much for your input. Much appreciated.
 
In general 25:1 or 4% is the baseline for old school aircooled 2 strokes.

Engine desingers use percentage numbers like 5% or 4% oil.

Dyno runs may use as much as 8% or more oil.

This is what I use with the HT after reading Gordon Jennings & Graham Bell's texts on the subject of 2 cycle lubrication.

20:1 with mineral oil for the first 2 tanks.

Then quality synthetic at 30 to 1 after that.

More oil is more power with these old tech 2 strokes.

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

40: 1 or leaner will lead to seizures and or fast wearing of the rings/cylinder on these air cooled motors.

Modern watercooled 2 stroke engines speced for using synthetic oils are another story...

40:1 is common

Thats where the confusion starts.
 
Last edited:
In general 25:1 or 4% is the baseline for old school aircooled 2 strokes.

Engine desingers use percentage numbers like 5% or 4% oil.

Dyno runs may use as much as 8% or more oil.

This is what I use with the HT after reading Gordon Jennings & Graham Bell's texts on the subject of 2 cycle lubrication.

20:1 with mineral oil for the first 2 tanks.

Then quality synthetic at 30 to 1 after that.

More oil is more power with these old tech 2 strokes.

http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

40: 1 or leaner will lead to seizures and or fast wearing of the rings/cylinder on these air cooled motors.

Modern watercooled 2 stroke engines speced for using synthetic oils are another story...

40:1 is common

Thats where the confusion starts.


I couldnt agrre more now with that in mind inb4 threadlock/flamewar
 
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