johnson 10 hp QD 15 prop.

[56 gull]

Just got a QD 15 the other day, the prop. seemed loose and had a large washer under the prop. nut, a brass cotter pin was used on the prop. nut. Under the prop. was a piece of ardox nail, the prop nut wouldn't bring the prop tight and still allow the cotter pin to go in. I understand the std. prop. for this motor is a 9x9, I have a nice 9x10.5 that fits great. My question is would this 9x10.5 prop. be suitable for use on a 14.5 foot semi dory of 40" chine beam that I expect to weigh around 200-250 lbs. empty and 500-600 lbs loaded?

 

[HighTrim]

Re: johnson 10 hp QD 15 prop.

You wouldnt happen to have a tach would you? I realize likely not, but would make it easier to judge your WOT RPM.

Others with similar setups would be better suited to help.

 

[56 gull]

Re: johnson 10 hp QD 15 prop.

Thanks, yes I'll probably get a tiny tach as there are quite a few motors I'm trying to get tuned up. Does anyone know if the standard prop. for this motor is a 9x9 three blade?

 

[steelespike]

Re: johnson 10 hp QD 15 prop.

QD15 is a 54 according to the 52 & 55 catalog a 9 X 8 3 bld. is the standard prop. Should be the same for yours.I'm pretty sure the 10.5 will be too much prop.Why not add another washer under the nut and of course a proper pin.
As I recall the nut is snug not tight.

 

[56 gull]

Re: johnson 10 hp QD 15 prop.

OK 9x8 std. then. Have proper drive pin now. Checked out the info on Max's Duckworks site re: service bulletins on prop. nut tightening for old OMCs. One of the props. has some side play, I mean the difference between the two is that both slide on easily, but one seems to have a well worn bore. How much is too much? Thanks for your help. Phil

 

[steelespike]

Re: johnson 10 hp QD 15 prop.

OK 9x8 std. then. Have proper drive pin now. Checked out the info on Max's Duckworks site re: service bulletins on prop. nut tightening for old OMCs. One of the props. has some side play, I mean the difference between the two is that both slide on easily, but one seems to have a well worn bore. How much is too much? Thanks for your help. Phil

Wouldn't seem to me the bore could wear much.Try them both use the smoothest operating one.But the 10.5 is surely too much.But might work great on a light fast boat.Also might be in demand. Wonder if the 9 X 10.5 is for a 15 hp. 9 X 11 is standard on the 15 ,9 X 10 on the Gale 12 full gearshift.

 

[56 gull]

Re: johnson 10 hp QD 15 prop.

So it might be ok on a minimost or minimax?

 

[steelespike]

Re: johnson 10 hp QD 15 prop.

Yes but might be interesting to see a speed prop on that little boat if you could find one.