difference between VE157FM2A and TH139QMB By captonzap (Read 1,519 times)

[captonzap]

Hello,
Can anyone tell me the difference between these two style engines, both 50cc? VE157FM2A and TH139QMB
One is on a Vento and the other on a Meitian. Do they both use the same CDI?
Does anyone have an electrical schematic for a Vento GT5 50cc scooter?
Thanks, CZ

[rob63]

They are different engines both in layout and capacity. The 157 is a 150cc but not a GY6 type, the 139 is a 50cc GY6 type. That`s about as much as I can tell you.

[Bashan]

First of all, if the stock stator for the engine has a magneto coil, i.e. a dedicated coil with it's own wire, that would mean it was designed for AC. If there is no magneto coil then it was designed to fire the CDI off of the battery which is an DC system. However, you could configure the system to work off of AC or DC, but it would be more problematic than using the stator as designed. I can clarify all that if need be.

I made a template for these engine codes but have never used till now. For you new folks the stamp is on the lower left front of the engine:

This first one is just an example of a stamp that fills all seven possible slots. If a slot isn't used there is no blank, the symbols are pushed together:

The first code in question is very odd and doen't seem to fit the conventional wisdom on engine codes. Here's the first using the template:

I'd have to bet it's a Vespa (VE) design but I'm guessing. And what does the "2A" mean for the engine size? If the A means it's under 50cc with a 57mm bore that's one under stroked SOB.

Here's the other one:

Pretty straightforward, standard 50cc GY6 with 39mm bore. The precursor TH is probably just the factory of origin.