Prop worries - another thought

[Spindrift]

As a follow-up to my previous post, in the darkest recesses of my garage I have a bronze Mercury prop which is a 15" pitch but on 13 splines. Does anyone know if this can be re-bushed to take an 11-spline centre sleeve, thus enabling it to fit my engine?

It would mean running the engine at slightly higher revs, but speed is not my main concern at the moment, though it would be useful to see what it takes to get the boat up on the plane.

[Howstar]

Do you have photo of the prop as i might have spare one, i have got one PROP and gearbox part it is a red band 50 hp not sure how many splines

pm me i will send you an email

[Rapier]

Not sure what motor you're running, is it on the Kent? If so I think 15 would be a bit steep for it and am not a fan of bronze props due to their weight. The 350 & 500 till 1969 were 11spline. 1970 and on motors were all 13 spline. Changing the hub won't change your speed / rpm though. Re-bushing is not a great option with old props - not sure if you'd find anyone to do it and guarantee their work. However, 11 spline props are readily available, lots of used 11 /12 & 13 pitch, if you know where to look. I think some are still made in the US by 3rd parties, but a lot of dealers here might still have OEM NOS stock on their shelves. The Mercury manuals list prop part numbers and estimated speed / load, so a net search on those normally throws up something.

[Spindrift]

Not sure what motor you're running, is it on the Kent? If so I think 15 would be a bit steep for it and am not a fan of bronze props due to their weight. The 350 & 500 till 1969 were 11spline. 1970 and on motors were all 13 spline. Changing the hub won't change your speed / rpm though. Re-bushing is not a great option with old props - not sure if you'd find anyone to do it and guarantee their work. However, 11 spline props are readily available, lots of used 11 /12 & 13 pitch, if you know where to look. I think some are still made in the US by 3rd parties, but a lot of dealers here might still have OEM NOS stock on their shelves. The Mercury manuals list prop part numbers and estimated speed / load, so a net search on those normally throws up something.

The engine is a 1952 Kiekhaefer Merc 500 and I am running it on the Kent. I have to admit that I'm a novice when it comes to understanding props and their characteristics, but I'm learning fast. I will certainly have a look on the net and see what I can come up with. Thank you.

[Rapier]

Follow on to your other posts...

The '62 500 is a 45hp powerhead rated motor, so for it to sing properly on a 16ft boat, I'd not expect much more than a 13 pitch prop. The manual suggests either a 10 3/4 (or 11" diameter) x 13 pitch for gross loads of 700 to 1300 pounds for 14 to 16 ft. The steepest pitch I used on an 11 spline was 17, but my later 500 refused to rev properly and that was on a 13ft 6" boat, albeit a hefty build. I have Radice racing props for the 500 at 16 pitch, but again they were used on a light rig for racing (they have no shock absorption in the hub too, so a no-no for daily running). The 17 pitch is a 10 3/4 bronze only, with approx boat size 12-14ft and up to 850lbs gross weight, so a very light boat Is it this hull minus the fins and roof? http://www.fiberglassics.com/library/Fi ... b60002.jpg Were you running a rev counter on the boat? Full throttle range should be between 5200 to 5600rpm for the 500.

Part number for the 13pitch is A-48-32182A1 or 32180A1

[Spindrift]

Thank you, Rapier. Yes that's the boat. The info you provide is very helpful. I didn't have a rev counter at the time (it arrived whilst we were away in Norfolk grinding the prop into Blakeney's gravel). Now I have it - an original Airguide model - I just need to work out where to connect it into the engine.