Power Prop for Johnson 70

[Straightup]

I have an extremely low time '84 Johnson 70 on my Rinker V153 (Runabout). Prop right now is a 13 1/4 X 17. With just me in the boat it scoots in the upper 30's, but getting skiers and tubers on plane takes quite a while. Any comments appreciated. Jeff

 

[JUSTINTIME]

Re: Power Prop for Johnson 70

go to a 4 blade if u want better hole shot

 

[xtraham]

Re: Power Prop for Johnson 70

I have the same setup up, is your prop ss or aluminum?
what are wot rpm's ? I dont think a 4 blade is the answer, it is more than likely a set up problem. your a/v plate should be @ least 1" above the bottom of the haul.
the 13 1/4" x 17" prop should be fine you may need to vent your prop for a better hole shot, but hang in there the pros will be here soon and lead you in the proper direction.

 

[Silvertip]

Re: Power Prop for Johnson 70

Without some wide open throttle numbers we can't be of much help.

 

[cougar1985]

Re: Power Prop for Johnson 70

for ski-tubers why dont you try a 15 p?

 

[Straightup]

Re: Power Prop for Johnson 70

I'll give you all the info I can, but i may be out of luck as my boat has only one gauge and that is trim position.

Prop is aluminum and is the original prop and is in almost new condition. Even though my boat and motor is 22 years old, it has yet to see 100 hours as my brother in law had it all that time and only put 20 to 30 hours on it. I used it about 60 hours last summer (I bought it from him) and have only been out 4 times this year, so probably just hitting 100 hrs. The rig is in new condition, except for my ski storage walls (on each side of the boat) have pulled away near the center of the boat and you can see the floatation foam for a 1 foot section on each side. It's pulled away about an inch at the worst part. Maybe he over packed them once, or it was a weak spot in the design?

I measured my plates in relation to the bottom of my hull. Right where the lower unit splits there's a small plate that goes foreward. That plate is 2 inches above the bottom of the hull. The main tail facing plate is almost exactly in line with the bottom of the hull.

Thanks for all the comments. Jeff