Engine

1985 RZ350

RZ350 - Removing the Power Valves

The power valves can be removed from the barrels only after the barrels have been removed since the power valve is a two piece item that splits and is removed from either side.


The first step is to remove the central bolt from the left hand side barrel on the side that faces out from the motorcycle. This will allow you to remove the pulley system and housing. If it is hard to remove you can hold the other end of the power valve with a wrench.


Once the pulley has been removed it is necessary to remove the inside casting of the pulley housing. This is held in place with three Phillips head screws. If they are stubborn, they may need an impact driver to remove them without destroying the heads.


On the inside face of the barrel where the coupler was located, you'll find a small retaining piece of metal that fits into a groove in the power valve. It is held in place by a single allen head bolt which needs to be removed.


Once the allen head bolt is removed, the retainer can be removed and stored for the rebuild.


Each power valve has a central allen head bolt that holds the halves together. To remove this it is a good idea to find a piece of wood or a similar soft material and stick it in the exhaust port to jam the power valve and stop it rotating. Loosen and fully remove the allen head bolt.


Carefully use a small flathead screwdriver to ease the power valve half from the barrel. Insert the head in the same groove that the metal retainer plate uses to hold the valve in place and lever it out of the barrel.


It should come free quite easily with a little resistance from built up carbon and oil.


The second half can then be pushed through the other side of the barrel.


Be sure that both locating dowels also come out with the power valve. Usually they will stick in one side of the assembly like shown above


The second barrel without the pulley system is very similar but the outside face of the barrel just has a simple cap held in place with two small bolts.


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