Scoot F.A.Q.

Q. What is the difference in a 139QMB and a 1P39QMB?

Essentially there is no difference, other than one has a P in the code. What the P actually tells us is that the engine is a horizontal cylinder engine. Some manufacturers may be more likely to mark their engines with or without the extra character, but even the ones without the P are still horizontal engines.

Some have claimed that having a P coded engine designates 69mm long valves instead of 64mm long valves. While it is true that there are many P coded engines with 69mm valves, there are also P engines with 64mm valves so the engine code does not reveal valve length.

Another misconception for a while was that the P code meant the engine was a "secret 63". That's a stock engine with a 44mm bore, making it roughly 63cc instead of 49cc. There were many 44mm bored engines with 1P39QMB coding, but the also existed with 139QMB engine codes. Once again the P code didn't designate what it was hypothesized to.

The engine code located in front of the oil drain plug and below the CVT.
Just behind the engine mount bolt.
Engine Code Location

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