What is this mystery of an engine?: LJ1P38MB

[fugaziiv]

Oct 25, 2022 3:22:50 GMT -5 aeroxbud said:

That's great you are on the right track.👍
It's a strange engine, more advanced than the normal GY6. More like the 3 valve Vespa probably. I wonder why we didn't see more of them. Perhaps it's just a cost thing?

It's a Chinese copy of Yamaha's 3V design used in the Zuma 50F and C3. We didn't get much of the Chinese version because it is quite a bit more expensive and complicated than the QMB139 and therefore there wasn't a huge cost differential from the actual Yamaha products.


Matt

[scootersteve420]

I am grateful for all the information and help from this group! I came in here with a $300, barely running scooter and little knowledge on how to fix it. Now it runs like new! The fix was a new carb, proper air fuel tuning, 2.00mm shims in the intake valves, they had 2.40mm originally. A 1.40mm shim in the exhaust valve, which was missing a shim.