Prop question on Merc 60EFI 4 Stroke

Hi,<br /><br />I have a Mercury 60EFI on a fiberglass runabout boat. The boat with 3 on board is approx 1300lbs. At the moment I have a 14 pitch standard 3 blade aluminum propeller. Top speed is very good, but it has a little trouble getting on the plane. Also, WOT is reached fine.<br /><br />I have the option of changing to a 4 blade prop, or a 3 blade prop with a larger surface area (both at a 13 pitch). Has anyone had any experience of this situation? I don't want to consider stainless because of the price.<br /><br />Thanks!!

Re: Prop question on Merc 60EFI 4 Stroke

You might want to consider this.<br /><br /> http://www.iboats.com/mall/index.cgi?prod_id=39283

Re: Prop question on Merc 60EFI 4 Stroke

skirkpat<br />When you say you have trouble getting on plane, is the prop spinning but not getting enough bite or is it just slow/sluggish? If the latter, you might consider having a vent hole drilled in the hub on the back side of the leading edge of each blade. This will inject exhaust gasses over the blades, partially ventilating the prop. The engine will rev up more during take off. After getting planed out the water rushing by will force the exhaust gasses back out the center of the hub. I have a 140 Johnson 4-stroke and really had a hard time getting the hole shot and top end in balance. My engine was weak out of the hole but strong on top end which I think is typical of 4-strokes. Venting will allow you to improve your hole shot while retaining your top end performance. This really helped my situation. Talk to a prop shop and see if this is feasible on an aluminum prop, mine is stainless. If you want to better understand the principle, go to the Merc site and read about "PVS" http://www.mercurymarine.com/

Re: Prop question on Merc 60EFI 4 Stroke

Skirkpat:<br />Propping correctly is the key to performance. I have a 70 suzuki 4 stroke and the holeshot is impressive. I can pull a slalom skiier out of the water no problem. I run a 17 pitch on mine and at wide open throttle I reach the max rpm recomended for that outboard. Having a tach is a must to prop correctly and getting the best overall performance. What is the full throttle rpm on your boat and what is the maximum rpm recomended for that engine? If your rpm is below the maximum recomended rpm try dropping the pitch.

Re: Prop question on Merc 60EFI 4 Stroke

I am reaching WOT (6000rpm). Since posting this message, I have been told by my local Mercury rep that I should be using a 3 blade prop with a large surface area. He said these props are designed for the 50/60 4 Strokes.

Re: Prop question on Merc 60EFI 4 Stroke

... the prop he mentionned had the same pitch (14") but it has a larger blade area - I assume this would help grip better.

Re: Prop question on Merc 60EFI 4 Stroke

I've got the same motor-merc 60hp 4stk. Dealer put a 16p aluminum. When I went to SS, I asked him to give me as much pitch as he possibly could to get more top end. He went to a 17p SS-I think he was covering his but. I'm not sure if I could go even further (I'm in the process of getting a tach so I can find out).

Re: Prop question on Merc 60EFI 4 Stroke

Sometimes increasing pitch can actually drop speed if the motor is lugging. Best to try and prop the boat so it will reach the maximum rpm rated for a particular outboard. Easier on the engine and probably will be the most fuel efficient as well. What is the max rpm for that engine. Must be close to the 6000rpm you're reaching.

Re: Prop question on Merc 60EFI 4 Stroke

I'm reaching 6000rpm which is the maximum. Thats why my local Mercury dealer suggested I try the same pitch prop, but with a larger blade area. This should help bite the water better on acceleration.