Help ID Mariner 15hp 2-stroke for correct prop

[Fenlander]

I want to get a spare prop for our Mariner 15 before the hols. On the Steel Developments website I can sort out everything except the engine origin choice it gives me...

Either Mariner Jap Yamaha base 8 spline YA.... or Mariner USA version 8 spline MA.

Any ideas what the YA and MA mean?



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[uncle al]

if you look on the prop you might be able to see a number possibly starting 48-????? 12p they should be able to work it out from that ,or if the prop is of there will be a number stamped on the end that goes to the thrust washer that will be the pitch that is required

[Fenlander]

Thanks. Perhaps mine is already a replacement as there are no part numbers... it is stamped 9 x 9P though which is the correct dia/pitch. Just which of the two alternative hubs it needs to sort out before I order... I'll see if Steel Developments can advise on this.

[uncle al]

it is a 9inch diamiter and 9inch pitch, the pitch is the important one

[uncle al]

damn sorry i hit the wrong key, the propeller should be the pitch that allows your obm to rev at the factory reccomended wide open throttle with that particular boat,to big a pitch it is like starting of in your car in second gear not good, too small a pitch and that allows over reving at wide open throttle again not good as they both strain the power head and gears, there you are the black art of propellers in a nut shell

[Fenlander]

Thanks. Seems 9 is the standard pitch and replacements are available in 8/9/10/11P. Might just look at what folks think about going up a pitch... mind you we'd only benefit from that in dead calm I guess so perhaps not worth it.