Genuine LC vs Converted to LC engine

[oldschoolgarage]

Yamaha aerox engine LC vs a converted chinese clone engine. In a hypothetical scenario if parts are matched (EXCLUDING the gearing) will there be any differences in power output. And if so, what would be the reason for them? I am mostly thinking smoother ported cases and more ideal gear ratios?

[90GTVert]

I had someone on YouTube tell me that if I used genuine Yamaha cases I'd see some wild power increase. IIRC he said something like 10-20%. I asked why and for any evidence of this and that went nowhere.

If you were talking about something like a 5BM Yamaha case where they did some flow work and had a special angled reed block setup, then maybe I could see it being more powerful. For standard cases, I'd be pretty surprised if you could produce any substantial gains with just a standard Yam case vs a 1E40QMB.

If you are talking about the whole stock engine, then I could imagine that Yamaha would have a better and more consistent setup.

Having a parts fiche to order replacements from and better quality control and probably better materials would likely be the biggest benefits of the Yamaha stuff, aside from gearbox issues.

[benji]

Some of the Chinese cases are 'thicker' so you can machine more out of them for longer stroke cranks. The Yamaha cases get pretty thin when they are machined out for stroker cranks, or so I've heard.

Although, most of the Chinese cases I've seen have had shortcase style CVT covers and thin carters, vs the Yamaha Carter being much thicker in the 'swingarm' portion. This can be an issue when running a stretch or a hardtail, as the Carter can break in half.

[aeroxbud]

I would of thought there most likely is a difference. Probably not noticeable though.
Ped parts did an interesting comparison between a Chinese sports scooter, and an aerox. www.pedparts.co.uk/blog/chinese-2-stroke-moped-tuning-baotian-falcon

[Steve B]

I kinda figured a performance piped 50cc cylinder would over power a stock piped 70cc cylinder. You really see no difference with a 70cc kit unless you add a pipe. Nice article thank you for sharing Aeroxbud.