Amongst 5 bikes that I own [a Honda CB400SF Version S, RD250 G Daytona look alike, a RD350 LC non YPVS, a RD 350 Indian Version and a R1-Z], I am on the verge of buying a Yamaha DS7. This bike has a 6 speed tranny, cylinders, Heads and CB points electrical system - all from an Indian RD. FYI, the Indian RD is a scaled down version of the US's RD350B - it has a 30 BHP cylinders + matching Heads + front drum brakes of a DS7/R5. The owner also has DS7's 5 speed GB + the original 250 CC cylinders [no heads, unfortunately] with him as spares and is willing to part it along with the bike.
What is your advice? Do I continue to run it as it is OR should I plonk in the original 5 speed GB and 250cc piston ported cylinders OR should I plonk in the original 5 speed GB and 350cc piston ported cylinders of a R5? The present owner says that the original 250 piston ported cylinders + its 5 speed GB is best suited to its exhaust but could not fit these as he had misplaced the heads and has only the choke side carb.
I heard that piston ported cylinders are bad at low speeds, guzzle lots of fuel, is prone to plug fowling etc but has raw power which we can feel in our hands when compared to reed valve cylinders. And hence, there is a cult/fan following for these machines. Is it true?
Please let me know. Basis which, I will decide to purchase the DS7.
Anyone have suggestions? I agree with the seller in that the 250 items are probably best suited for the 250 exhaust, but the increase in power could be helpful, if RK would be willing to go aftermarket with the exhaust and fiddle with the jetting...