YS 91 Valve timing?
 

I had to change the bearings in my YS 91 FZ.
Do any of you know how to set the valve timing right? I was stupid enough to forget to check this before I took it apart...[:o]


Thanks

Lars

RE: YS 91 Valve timing?
 

Get the piston on top dead center. On the AC version, ther is a mark on the prop drive hub that will correspond with a casting seam on the engine.

There is a mark on the cam that must be aligned with the pushrods.

Take the rocker arms off and raise the exhaust cam follower up out of the way so that you can seee the mark well.

Set the cam position and re-install the rocker arms.

You will need to adjust the valves. All the current four cycle engines use the same valve gap. It's about .002" -.004" which will get the job done except for a purest.

RE: YS 91 Valve timing?
 

What happened to your bearings ??? [:o]

RE: YS 91 Valve timing?
 

to add to w8ye, with the piston at tdc the timing mark on the cam will sit straight up!

RE: YS 91 Valve timing?
 

Thank guys!

Flyboy: They got worn out...