[Ed68]

We received our CP 11.1 piston today. The ring set up is a little confusing,
top ring seems fine, second ring does not have an oil scraping lip as shown
on the literature. I called CP, they said the lip would be found on their big
bore pistons, but not on the 74mm model.
The piston is unmarked for exaust direction. I was told the larger valve relief
was the intake and the deeper one was the exaust.
Can anyone confirm or dispute this information?

 

[b40huckers]

larger is intake, deeper is exhaust side.

 

[Ed68]

Thanks, do you have any experience with this missing o ring on the bottom of the cylinder. It is shown in my manual but not in any of the parts websites nor is it in my gasket kit.

 

[b40huckers]

Thanks, do you have any experience with this missing o ring on the bottom of the cylinder. It is shown in my manual but not in any of the parts websites nor is it in my gasket kit.

the only thing on the bottom of the cylinder is the dowel pins and the gasket. A picture would be helpful.

 

[b40huckers]

are you talking about the brass o rings for the oil line into the side of the head?

 

[Ed68]

Thanks so much for letting me in on this. In the Yamaha shop manual it shows an o ring or washer under the cylinder. I thought it must of went into the crankcase. After looking into it some more it seemed like I was looking for a ghost. Thanks for saving me from splitting the cases. I guess Yamaha deleted it from production but it was left in the manual, as all the oem sites don't show the part.