Correct propeller help please. 4.5hp Johnson (not a misprint on Hp)

[Glenno]

Hi all,
I am a fellow racer, I dont race the 4.5hp though, would be a long slow race!
Just wondering if any one else has a 4hp or 4.5hp deluxe johnson (around 1981 mod) that would be willing to check the diamiter and pitch of there prop.
Mine has a 8.5 x 9 which as far as I can reserch is off the 7.5hp and 8hp models which share the same gear case with the same gear ratio. So the 4.5hp battles to turn the 9pitch.

any help would be really apreciated.
Cheers,
Glenno

[Fastjeff57]

Some might chuckle at 'racing' a 4.5 hp. boat, but not I. Cottage Class boat racing is very popular on the Chesapeake Bay, with tiny hydros driven by 4 to 6 hp motors.

Jeff

[36run69n]

iboats.com lists two props for 4 hp 1981 Johnson (4.5's were 83-86) props listed are 8x7 and 8.5x9 (the 9 must be the race wheel) both are 3 blade.

[champ20B]

Hi all,
I am a fellow racer, I dont race the 4.5hp though, would be a long slow race!
Just wondering if any one else has a 4hp or 4.5hp deluxe johnson (around 1981 mod) that would be willing to check the diamiter and pitch of there prop.
Mine has a 8.5 x 9 which as far as I can reserch is off the 7.5hp and 8hp models which share the same gear case with the same gear ratio. So the 4.5hp battles to turn the 9pitch.

any help would be really apreciated.
Cheers,
Glenno

Glenno, there were three different props used on these.

If it is weedless, it is 6-1/4" X 6 pitch and is part# 0319004.

If it is a standard gearcase, it is a 7-1/2" X 7" as a standard issue prop #0319774.

If it is a standard gearcase and the prop is painted black, it is 7-1/2" X 6" part# 0317499.

This engine did not have the 8hp unit either. Your's (if it is a 4hp) should be a non shift as the others of higher hp rating were shifting types. Also, the 4hp was a low rpm engine. It had aluminum rods and wasn't made to run more than 4000-4500 rpm max. It normally runs a bit less rpm under load regardless without compromise. I had a 1972 model (weedless ) and I could start it warm by spinning the flywheel with my hand instead of a pull start. The compression was so mild under normal condition, it seemed almost absent. It ran real good, was reliable, and it was a great little trolling motor though.

[champ20B]

A correction I want to make to my last reply is that the (4.5 deluxe) is actually a shifting model. But I was talking about the regular 4hp by mistake.

Now, for the 4.5 deluxe shifting model, the propeller is a 8" X 7" and is part# 0391096.