Bashan 250cc engine to a motorcycle

Hello!

Im new here, and I thought I would get help from here, because you have experience from chinese engines. :)

So, I am currently thinking about swapping a Bashan 250cc engine (water-cooled, with reverse) to a motorcycle (Derbi Senda 125, air-cooled). The big question is, are there any gearboxes available, that fit in to this Bashan engine. I am buying an used engine, so I'll change the bearings to higher quality bearings while the engine is as parts.

The best would be a wide-ratio 6 speed gearbox. My current engine has 5-speed and it does about 95km/h@gps.. and it isn't really powerful at all for me.

I have experience of porting 2 stroke engines, but I think, with help I can get a bit more power from the Bashan engine.
If I just smooth out the ports, I might get about 0.5-1bhp. That kind of porting is called as "Stage 1."
Also I was thinking about raising compression ratio and start using E85 fuel. I'm running the current engine with E85 fuel and it uses it about 4 litres per 100km.. and E85 costs about 1 euro in Finland.. so it is very, very cheap to use the E85 fuel.


I apologize my bad english.

-John

http://item.taobao.com/item.htm?id=10291449950

Thanks!

I changed my mind.. so I bought a CG200 OHC engine without cylinder head.. I paid only 40€ of it and I probably might be able to use the 125cc engine's cylinder head on it. I just have to be careful, I don't blow up the engine, because a valve is hitting the piston or something like that.

But a 6-speed gearbox would make it a lot better. I don't really like my current engine's missing 6th gear, when I'm driving over 60-80km/h.
So.. I've got to order that. I appreciate your help a lot! Thanks again, humanbeing! :)

"200" head cover is the SAME as "125" in most case.
http://item.taobao.com/item.htm?id=18688252538 [As the oil cooler seller said]
---
125 & 200 in/ex valves had BiG size difference
http://item.taobao.com/item.htm?id=8432093238

Okay, so then I could buy just the cylinder head, including valves, springs etc.

What if I'd use a 250cc inlet valve? It's ø34mm and the head would require machining. Probably with head porting, larger inlet valve, modified camshaft and higher compression ratio, I would be looking at 17-19whp? Ignitech sells awesome tuneable CDI boxes. That would make a difference on it and the revlimit can be changed (e.g from 10 000rpm to 12 000rpm).

My budget is around 150€.. so I could do all that with 150-170€, because I am not sure about the shipping costs.
That includes the 6 speed gearbox, cylinder head, 250cc inlet valve...