will 5 speed trans fit the 4 speed tans engine?

[johnny27]

Hi Guys, i have a 250cc atv, its the watercooled 250 engine. I have done a few simple mods to the engine, and i find its really a responsive engine to tuning. I am buying a performance cyclinder head from MRP for my quad. Hopefully it should give me a good power gain with the other mods i have done.

However, as you know the top speed is quite poor on these quads, although the mildly tuned engine is very capable and fast accelerating thru the gears, but the top speed is quite dissapointing.

My quad is the 4 speed transmission with a reverse gear. I notice that most of the dirt and trails bikes, like the lifan gy200 have 5 speed transmission. I wanted to know if it is possible to remove my own 4 speed transmission and to mate the 5 speed transmission to my 250c watercooled engine? Say using a lifan gy200 bike transmission

I understand i would have no reverse gear but i don't care, as i would have 5th gear for more top speed, plus i reckon using the new performance cyclinder head with my current mods, i could affoard to use a bigger front sprocket or smaller rear sprocket , for better longer gearing, hopefully my engine would be fit power wise to pull thru the gears?

Please can anyone tell me will the 5 speed transmission mate with my current engine, and also, what would be involved in changing the transmission, what would i have to buy apart from the transmission stuff? I am worried because i don't know if the air cooled trans is compatable with the water cooled trans engine? The two engines look very similar though, so if any could help me out with some knowledge.

And i know most of you think it would be a waste of money because the quads are worth very little, i do know that, but i love to be able to show ppl that you could make a chinese quad decently fast, and to show that they are a good alternative for brand names, since there is a growing market for tuning performance parts for chinese engines. The idea of making a cheap chinese quad competitive power and handling wise against brand name 250cc is a good chalange for me, i would enjoy that, although i still would'nt be doing jumps with it. Thanks guys

[katoranger]

I don't know if about fit, but my thinking is that the 4-speed trans is probably going to be a stronger unit. You would probably be better off just trying different sprockets.

Allen

[johnny27]

Thanks for your reply, i will try using longer geared sprockets in the mean while. Hopefully i will get the new cyclinder head soon, so if i can get abit more power from the 250cc engine, i can afford to use londer gearing. Although i would prefere to use a 5 speed gearbox, since using too large of a front sprocket will probaly put strain on the clutch while taking off. Plus the five speed transmission would have better gear ratio's than just gearing out a 4 speed box. Thanks

[warrior91]

drop a couple teeth in rear sprocket