well i put the rd350 yvps engine in my banshee to try it at a mx meeting at the weekend,the only problem with it is that the power valves at missing great for open track as the power comes in at about 8000rpm with a kick like a mule, but the track that i was racing was very tight and twisty
my question is as i am unable to get 2nd hand ones at a breaker do i.

1) bight the bullet and buy yamaha ones new (costly)

2)have plugs made up so it blanks half the exhaust port up to give me bottom end power (remove them for open tracks)

3)change the gearing either smaller front sproket or larger rear,to make it rev quicker to keep it in the power band

thanks
trigg

 

Im not positive on your motor. But for us we have been able to tie the power valves open if the need arised. If not (i dont know anything about your motor) if its a vacuum type powervalve see if you can find a softer spring to put in there which will allow your powervalve to open at a lower rpm

 

Is it an RD or RZ engine because as far as i know there are no powervlaves on the RD engine.The PVs on the RZ engine are electrically controlled so i am not sure wich parts you are missing, is it the electrical assembly or just the PVs or both?

Anyway do a search on Bansheehq there are a few guys on there that have made the conversion from the regular Banshee to the RZ engine, they should be able to answer all the questions you can throw at them.

 

Yeah, i seemed to remember the yvps with electronic powervalves which ran off the CDI. If thats the case I would think you could replace the springs with a lower tention spring to open up sooner in the rpm band

 

they are electronic but all i have is the motor minus power valves the motor was replaced because the power vavles whent wrong


trigg

 

You guys are good. im not sure what his problem is, from reading his post!!!!

RoostKing...

 

I was thinking the same exact thing... I have no idea what the problem is. I guess he's saying the powervalves aren't working right - all top-end power.

 

Me three, I read it several times and was not sure what the question was. Of course I know nothing about the rz powervalves, so that might have something to do with it.

Bat

 

Well it is pretty simple in a sense, he has RZ cylinders on his Banshee but he is missing the powervalves "guillotines" so he is kinda running the equivalent of stock cylinders that would have been ported for dune riding...Not very good for tight and twisted stuff.

 

imback is right i suppose my explaination was not that good but i am british!!
power valves missing it's like a ported engine bad in thight and twisty stuff, would gearing solve it


trigg