I have a merc stainless three blade 17 pitch prop that looks pretty good for waterskiing to me. I think I will modify it and try it on my Johnson Fastrike. The part number is no longer referenced in parts express. It is a 48 79794 A4. Do any of you merc guys know what it is? I like the looks of it. It has very little cup and rake and the blades are mounted further forward on it than my OMC props. That should have less torque steer. I'll have the shop take the cup out and we will see. jim
Last weekend as we were putting boats in the water up north, the question of props came up. As near as I can tell (not knowing much about props), my brother's boat (17' Glastron w/ 135 Optimax) has a 21 inch pitch prop. It is hard to read the number on it but I can see that it has an "M21" on it. We'd like a touch more pull out of this motor and I'm guessing we can get it by reducing the pitch a bit - perhaps a 19, keeping in mind that this boat is also a touring boat and lake runner, so I don't want to suck all the top end out of it. Nor do I want it to over-rev, as there are innexperienced drivers using this boat. Does anyone have any suggestions? Also, we are using alum. props on this boat and we are going through a couple props a year due to the fact that it is not quite deep enough at the pier and we've got drivers in the family who do not appear to understand the concept of electric trim. Given this, I suggested to my brother that he use a stainless prop, which would wear better in the sand, so-to-speak. He is concerned that a stainless prop will simply transfer damage to the lower unit or crankshaft. Can someone offer some thoughts on this? Is it more dangerous to the motor to go with a stronger, stainless prop? Or are we wasting money rebuilding props every year? Thanks for any help anyone can provide on these questions! MarkBano
Mark, The motor has a rev limiter so it won't over rev. I would try an aluminum 17 on it to see how it works. The aluminum props that you have can probably be repaired and re-pitched to a 19. When you arrive at a good pitch, then consider a steel prop. When you see the prices of them, you may change your mind. The cheapest way out of this problem is to educate or eliminate the offending drivers. The steel props are widely used. They are more rugged, but they can be damaged too and are more expensive to repair. They are harder on loiwer units. I have run the same aluminum prop for 10 years with sending it to a repair shop. So, it can be done. The beauty of an outboard is that it can be trimmed up in shallow water. Take the prop off and look at the number on the hub. jim
That sounds like good advice. I'll check into the re-pitching repair. That would be great because we've got 2 or 3 props. As for educating or eliminating offending drivers, I have to laugh at the thought, because my oldest brother owns the boat and I'm sure he'd like to do some eliminating.... :twisted: Between my brothers, my father, and myself, all we do is repair and replace damaged equipment. I'll not be insensitive to the audience here - particularly since I never know which of my relations is visiting this website.... Suffice it to say we've got many drivers, of many ages and abilities, and we've tried education for years to little avail... This past weekend, after putting the docks in the water, which is still at a low level pending the letting of the dams, I noticed the curving trench in the sand where the boat is driven away from the dock "L". It is probably a 6 or 8 inch deep curving trench that travels out for about 30 feet. My dad and I were looking at it in amusement. We may need to think of some more aggresive strategies. Like a bullwhip....
