Prop identification help

[Douglas C]

I have a Johnson 90hp of 1988 vintage, currently fitted with a stainless steel prop marked 1518PP (or PF) Edit...Now found that this is marked 12 3/4 x 21
I also have a spare aluminium prop marked only with 2827.

Can anyone shed any light on what the diameter/pitch of these could be? (Diameter I can measure, but pitch would be more of a challenge!)

A third prop is marked 13-1/4 x 17, which is the sort of marking I was expecting to see on the other two.

Thanks

Douglas

[Downhilldai]

The first figure is the diameter and the second is the pitch, in inches.

[Sonar]

Originally Posted by Douglas C

I have a Johnson 90hp of 1988 vintage, currently fitted with a stainless steel prop marked 1518PP (or PF) Edit...Now found that this is marked 12 3/4 x 21
I also have a spare aluminium prop marked only with 2827.

Can anyone shed any light on what the diameter/pitch of these could be? (Diameter I can measure, but pitch would be more of a challenge!)

A third prop is marked 13-1/4 x 17, which is the sort of marking I was expecting to see on the other two.

Thanks

Douglas

This seems a complicated way to find the pitch of an unknown prop so here is the link.

http://www.ehow.com/how_5969692_meas...propeller.html

[9D280]

As DHD says, the "A x B" is "diameter x pitch" - the addition of the dash is down to numerical lingusitics.

I guess the 4 figure number is a part number, assuming the prop is of a ballpark same size as the other two.

[Douglas C]

Originally Posted by 9D280

As DHD says, the "A x B" is "diameter x pitch" - the addition of the dash is down to numerical lingusitics.

I guess the 4 figure number is a part number, assuming the prop is of a ballpark same size as the other two.

I'm ok with the pitch/diameter markings.
It's the one with the 4 digit marking that had me stumped.
I'll try and figure out those instructions!
Thanks

[aquatec]

The four figure numbers are possibly repair numbers stamped in by one of the prop repair companies. You will find a part number or the prop size on the central hub at one end or the other. On the back side of one of the blades or stamped on the side of the body of the prop. A photo might help.
Regards,
Aquatec.

[Douglas C]

I'll clean up the ends and have another look for markings.