TOPIC: new prop, won't plain

Had a GREAT time at the Chautauqua show in NY today! Met John and Tricia from Cleveland area and got to ride in a homemade and designed wooden boat...very cool!

So, I got an aluminum prop (same size as my brass prop and about half the weight) and it wouldn't get me up on plain...just plowed. So, i'm wondering if I need to trim the out drive down or up? I did get my old prop back, so I think I'll put it on in the morning and try it out at a local lake tomorrow. I figure, if I can get on plain with the old one, then it must be something that needs changing with the new one. Any ideas out there?

Oh yeah, I definitely will not be patronizing the local boat shop anymore...$109!!! He said he wasn't making anything on the transaction. I held my tongue. Sometimes, silence says it all...he knew.

What kind of motor? Why did you change from a bronze prop to aluminum?

109.00 is very reasonable for a prop and he probably did not make much on it.IF the props are indeed the same pitch and diameter you have a engine issue.To get it up on a PLANE quickly the trim should be all the way down,then adjust up as when you hit planing speed.

Is the new prop the same number of blades?

I know you get different performance from aluminum & stainless steel props of the same style, diameter & pitch. I'd expect a difference of some sort between aluminum & brass as well.

$109 for the rehub of the old brass prop after overnighting it because of their negligence. The new aluminum one cost me only $150...which I'm very pleased with the price!

So, I went to an aluminum prop just because I didn't think I would have the old one back in time for this weekend. I just left the new one on for the show yesterday. The engine is the volvo penta BB70 80hp with the aq100 leg. The trim bar setting has 4 holes. It has always been set at the third farthest hole away from the transom. So I can go out (raising the prop) one more hole or lowering the prop down 3 more 2 more holes.

Bronze props like the stainless ones today don't flex as much as aluminum so they provide better hole shot and fuel economy due to lower RPM's at any given speed. The ability of a boat to plane has many factors, prop size, materials, weight distribution, then wind and wave conditions to a small degree. This past weekend I had 4 people in my 18' bow rider with a full tank of gas, due to wind conditions everyone sat in the rear area. With 190hp and a stainless prop I chewed up several 100 yards before it finally leveled out and that is with power trim. Try lowering your trim drive pin 1 spot and that should help, putting the drive to far in can cause the front of boat to plow which uses way more fuel and badly affects ride.

I bought a new 4 blade to replace a 2 blade prop - same pitch. Radically different performance. Found out the surface area of the 4 blade was too much for the motor/gear ratio. Could you post a picture of both props? What is the size of the motor?