87 mercury 9.9hp 9"x9 pitch

[rainbro]

Hello I have a 12'aluminum boat.With the boat empty this engine works very well.When I install it on my 14',loaded with fishing gear and 400lbs of occupant, all it does is bog,and push water.It will not plane.I am looking at a 3 blade 9" x7" merc prop,thinking this may help.At a cost of $150.00 Canadian,this is an expensive guess.I have looked at aftermarket 4 blade 9 1/4"x 7 at a much lower cost.Any thoughts would be appreciated

 

[steelespike]

Re: 87 mercury 9.9hp 9"x9 pitch

Is the 14 a bare bones, no floor etc?I would get the 3 blade 7" pitch.
Keep in mind weight placement and trim are critical.
The boat should plane with just 2 guys in it.Try it and add weight to the point it stops planing then figure what you can eliminate.
A plastic 3 gal. tank,light danforth type anchor instead of a bucket of concrete,light styrofoam cooler,cans instead of bottles,10lbs instead of 20 lbs of ice,some sort of cover to keep the sun off the cooler.A pair of light plastic dingy oars instead of heavy wooden.With the 7" You may have to be careful not to over rev when no load.

 

[rainbro]

Re: 87 mercury 9.9hp 9"x9 pitch

Cans instead of bottles is a given! LOL.Found a quicksilver 7" for 110.00 Ordered it and hope to see it this weekend.Will post results

 

[LORDY611]

Re: 87 mercury 9.9hp 9"x9 pitch

There are also diff types of 14' boats. My Gamefisher (Sea Nymph) is a short-sided boat compared to my neighbor's Starcraft. My 9.9 Johnson not only planes with 2 aboard, I taught my 3 kids to ski behind it. That boat should fly. Mine is rated for 15hp and I almost think it would be scary fast that way. OK, not scary-scary, just ear-to-ear grin scary.

 

[rainbro]

Re: 87 mercury 9.9hp 9"x9 pitch

I installed the 7" prop.By myself, with full fishing gear, I am getting 17.5 mph.I have no tach but a educated guess would be 5500rpm.I am happy with that.However when it is at low idle(just trolling),I must slowly give throttle or it seems as it floods and dies.Other than that it is good.Any ideas