Are there any advantages to the 85-86 motors? The local motorcycle shop claims they like the older motors reed "block" design inside the cylinder rather than the 87+ external "cage" design and the non-powervalve top ends last longer or something? Any input people?!

 

I don't think there are any advantages.
They made improvements and that was one of them.
Then came the mighty powervalve cylinders. The best of both worlds (low end grunt and top end rpm's).

 

On on powervalve motors you had to be on the pipe to get the most power. Powervalve made it more rider friendly gave a broader powerband.

 

He said something about they are not truly power-valves since they don't change the power band range they just allow more exhaust to exit the cylinder during acceleration or something like that?

But the cage design is better then the block?
Is it true the 85-86 engines don't have to have the top ends rebuilt as often though?

 

I feel that there is no difference in the time for top end rebuilds between the powervalve and non powervalve.

Please allow me to explain what the powervalve does.
Understand that a non powervalve cylinder needs porting to raise the rpm's. When you raise the top of the exhaust, it increases rpm's. The more you raise the exhaust, the more top end rpm's but you sacrifice low end grunt.
The powervalve offers both.
What happens is:: The is a metal piece that fits in the exhaust port (the powervalve) once rpm's reach a certain point, this metal piece raises up thus raising the top of the exhaust port and allowing more top end rpm's.
When rpm's go down, the powervalve slips back down into the exhaust port and you have the low end grunt back.
The guy that said it just lets more air flow:: he's correct in the fact that it does allow more air flow but it's more of the fact that the top of the exhaust port raising indeed does change the powerband.

Hope that helps.

I feel the reed cage design is much better than the port reeds.

 

good man! Thanks