identifying Yamaha Prop

[2MADAKAT]

I have a 1991 Yamaha 115 ETLD engine. I bought a 17 pitch prop on Ebay and when I put it on my rpm dropped to 3500 max at about 26 - 27 mph. I put my older 19 pitch prop on and I get 4900 rpm max with 37 mph.
Is there any website available to find out the specs on props?

The 17P prop has 131/4x17K 4441 1 stamped on side.
On exhaust end it has stamped 17K Y3 6E5

The 19P prop only has CW7778 stamped on side.
The exhaust end is stamped 19K Y2 6E5

By the way, both props were new last year, so I don't think the hub is the problem.

Thoughts?

 

[walleyehed]

Re: identifying Yamaha Prop

Any indication of any work having been done to the 17?
I don't run any yammy props, but I think the "K" is a particular design, and I belive there is an "M" for another.
Maybe Dhadley can tell us the difference if he catches this...he does quite a bit with some of the yammys.

 

[ivar]

Re: identifying Yamaha Prop

On Yamaha props , "K" and "M" denotes hub size, K being the intermediate (4 1/4) gear case , the M for all V6 with the large (4 3/4) gear case.

I can't see why the 17" shoould drop your rpms that much, you have checked that it rotates freely etc?
Could it be that it blocks your exhaust or something?

 

[2MADAKAT]

Re: identifying Yamaha Prop

On Yamaha props , "K" and "M" denotes hub size, K being the intermediate (4 1/4) gear case , the M for all V6 with the large (4 3/4) gear case.

I can't see why the 17" shoould drop your rpms that much, you have checked that it rotates freely etc?
Could it be that it blocks your exhaust or something?

 

[2MADAKAT]

Re: identifying Yamaha Prop

Doesn't block exhaust at all. Hub appears fine. I am taking on a trip up north this weekend and will retry on
the calm waters of an inland lake.

I was hoping to find out how Yamaha labels their props to see if maybe I had a wrong rotation or wrong cup size.