2 blade prop on a 95 hp. Merc?

[stevestrib@comcast.net]

I have a 1968 Merc 95 hp. inline 6 that I am trying to replace the prop on. My current prop is a 2 blade with "W841" stamped on it. Does anyone know where I can find a replacement for the 2 blade? If not, what pitch 3 blade should be used for an aluminum 18' v-hull used to get from point a to b in Lake Michigan?

 

[WillyBWright]

Re: 2 blade prop on a 95 hp. Merc?

That looks like a rebuilder's stamp. You won't find 2-blades anymore. I'm guessing a 17p would suffice, but a 40 year old Merc in Lake Michigan?

 

[walleyehed]

Re: 2 blade prop on a 95 hp. Merc?

A Kicker may not be a bad redundancy plan
BTW, I do have 4 brass/bronze 2-blds for mercs....I'd have to ask Bruno about letting them go though....If the props available on iboats will fit, I can't offer any of these.

 

[Texasmark]

Re: 2 blade prop on a 95 hp. Merc?

Hey Ken. (Maybe Mr. Dhadley has some comments he wants to share with the folks too.....about the "good old days".)

Beins we're on the subject, back when the first towers came out and as they moved up to 100 hp and then turned black or vice versa, what sorta pitch were those OEM alum props? And why did they go 3 blade with the black colors?

Got any insider info as to why Merc used them back in those days? I know 2 blades is supposed to be more efficient, but was there more to it than that.

When it took to pushing a load, seems the OMC 3 bladers at their 4500 rpm and big displacement blocks did more than the screaming Mercs with their 2 blades, small blocks, and high rpm's.

A 6 cyl 60 on a 14' Yellow Jacket molded plywood would have been a screamer back then and a perfect place for the 2 blades.

Seems pushing a 20' cruiser, like a Lone Star or some of the wooden cruisers, would not have done well with the 2.

I had a Wizard 25 hp on a 13' wooden boat and I couldn't do much with the OEM 2 blade alum. Changing to a 3 blade MWC bronze helped but not much. I bought it from a guy who ran a 40 Merc on it and it ran out real good.....no instruments back then for us so don't know particulars.

Thanks,

Mark

 

[jimmbo]

Re: 2 blade prop on a 95 hp. Merc?

3 blade props were available for the older mercs. A 2 blade prop offered less drag than a 3 blade and therefore was slightly faster but wasn't as smooth as the 3 blader.
As for the "Fast but no pulling power Merc" vs. the "load lugging fat four". In the book 'Iron Fist" there were a few paragraghs about how johnrude dealers were spewing falsehoods about how much more lugging power the Johnrudes had compared to Merc. On dealer took two identiacal boats, put a 50hp V4 on one and a 60hp inline 6 on the other, secured the boats bow to bow and ran them WOT. Even though the Johnrude had 18% more displacement(70.7 cubic in. vs. 60 cubic in.) and should have more torque, the Merc pushed the Johnrude backwards.

There are plenty of pictures showing twin Mark 75 or Mark 78 Mercs pulling upwards of 15 waterskiers.

 

[Texasmark]

Re: 2 blade prop on a 95 hp. Merc?

Interesting comment about 15+ skiers with the Mark's. I had a '72 125 John on an 18' trihull and 5 was my best number and it took some doing to get them all to stay up long enough to say they were up.

Mark

 

[walleyehed]

Re: 2 blade prop on a 95 hp. Merc?

Vibration is one reason they changed to 3-bld...pulling power was another.
Works the same way a 4-bld does compared to a 3..

 

[jimmbo]

Re: 2 blade prop on a 95 hp. Merc?

Who says mercury was only a hispeed no torque motor?
Here is a pic of the Mark 75s or 78s towing a group

From IronFist.

 

[Texasmark]

Re: 2 blade prop on a 95 hp. Merc?

Jimmbo,

Absolutely amazing.

Wonder what props they had on those Merc's (78's?).

Having tried to get 5 up with no one falling down and requiring a restart, I can't imagine how many times they had to start to get this picture.

An amazing stunt for the engines and the skiers.

What is the name of that place in Florida where they did/do all those water ski shows, Crystal something?

Thanks for the pic.

Mark

 

[Texasmark]

Re: 2 blade prop on a 95 hp. Merc?

I just counted heads..................31. WOW! What a publicity stunt.

Talking about the Johnson Javelin 35 hp being sharp (back in the Johnnyrude threads today), this was probably the last engine that Merc built that was really sharp....kinda went hand in hand with all the chrome on the cars of the day. After that they started whacking things off, used a less costly logo (shroud front cover) and finally went to plastic.....but my plastic '02 is pretty sharp too.

Mark

 

[jimmbo]

Re: 2 blade prop on a 95 hp. Merc?

What is the name of that place in Florida where they did/do all those water ski shows, Crystal something?


Mark

Cypress Gardens

 

[MikDee]

Re: 2 blade prop on a 95 hp. Merc?

Cypress Gardens,,, I was there once, the scenery was beautiful, all kinds of plants, & flowers, and the shows were great. I hear it's gone now. Back when I went in the early 70's they were using (Crosby, or Crosley?) boat's with the latest Merc outboards.

 

[Texasmark]

Re: 2 blade prop on a 95 hp. Merc?

Yeah that's it; Cypress Gardens.....lots of Cypress and lots of pretty Oleander bushes and pretty flowers........and beautiful girls. Grin

Mark