Re: feel like I might have the wrong prop or be slipping a lot
ok first off you need 12 pitch prop to get it on plane. 19 is crazy and will never work.
12 inch pitch should get about 30mph plus,
then you can go up to a 15 inch pitch for a lot more speed on the plane with very good pull away (hole shot).
BUT
you will need to drill 3 holes in the prop at the bottom !!!! yep thats right just like the big boys with big 200hp engines.
DONT PANIC its very easy and very very simple to do and will NOT ruin a prop.
here below is a pic of the very same 15 inch pitch prop you need to get up fast and go fast once up on plane.
this prop struggled with 2 people to get up onto plane, the boat needed to have 12 pitch realy for pull away.
but once it got going it was ok and gave good high top end speed.
I then drilled 3 simple holes at the hub and the prop now gives quick pull away with 4 people in the boat,it realy is that simple.
the pull away is like a 12 inch pitch and the top end isthe 15 inch pitch,so i get the best of both worls in 1 prop.
The holes you drill in the prop work like this.
at idle and slow running speeds they let out a certain amount of exhaust if there is a lot of pressure from the water
at the open end of prop (thru exhaust ).
Now as soon as you hit the throttle the prop trys to move but pressure on exhaust holds it back a touch.
now this escaping exhaust also puts a touch of air to the blades letting them slip a bit, this slip lets the engine rev
and get to power faster.
now as soon as the boat starts moving the holes in the exhaust start to become less open due to water
flow going over them sort of closing them off.
once on plane these holes are now not working at all and in effect are closed off by pressure.
so we now have a 14 inch pitch prop ,but the boat is already on plane and the majority of power needed to get
the boat motivated as already passed,so now its just picking up more speed untill max revs achieved.
anyone who says this dont work , has never tried it, its amazing what it does.
DO NOT BOTHER TRYING THIS WITH 19 PITCH as the prop is just too big for the engine anyway....
please look for the numbers on your prop and let us know what these are, we can then tell you what the
prop size is and what its meant to be on.
i would think a 3 cylinder 75hp on a very lightweight boat.
anyway
here is some pics of the prop i drilled with huge success, just drill 1/4 inch hole in between each blade
then go up a size drill untill maximum of 3/8ths to 1/2 inch diameter.
i think 3/8 inch will be just perfect for your engine with a 14 pitch prop.
The prop in these pics is mercury 10.1/8 x 15p Black alloy prop ..part no 4873140 -15
.