Yamaha Moto-4 Questions

[wmmalett]

I have a late 80's YFM225 Moto-4 roller. I would like to go with a bigger motor, maybe a 350. What will be a direct bolt in motor/trans combo for this machine. It's a shaft drive with a center mounted driveshaft. Has anyone done a swap like this. If so what combo did you use and was there any problems doing it.

Thanks,
Bill