I have no idea what kind or make this hydro is??

[trident]

Yah, what he said...

Yah, what 55H said... See Sam Hemp or Darrel Sorensen for a D class kit boat. You and your Dad can build a couple of good boats that'll run fast and be way safer than this old desigh that wasn't any good when it was new. BTW, that old design was meant for up to a B size motor, not a D, like your 400. Turn that old boat into an antique 'show' boat. Bad design!

Note, I said safer, not safe. Any of this stuff is fast enough to hurt or kill you.

If you want to build up that M400, and put it on a 55H style Quicky, there is more to it than just bolting on the new unit. The powerhead needs to be prepped to run sustained rpm's in the 7000-8000 rpm range. It might do it stock, but not without risk of severe damage. I raced a M400 back in the day in early OPC (when it meant Outboard Pleasure Craft) and won some races with mine at around 7200 rpm on the stock shifting unit, but the powerhead had been prepped to M55H standards of the time. Merc 4's will scream, but they should be set up looser than stock pleasure motors... I raced 55H's and 44XS' in D hydro, and they ran mid to low 7's. We loosened those up in the bores and bearing clearances. Raced Merc 40 c i and 44 c i Mods, winding into the 8's, but again, not at stock clearances.

Keep in mind, a good D, a 44, with current props on a current design hydro runs over 80 mph! Please wear a Snell aproved helmet and a competition lifejacket (contact SRP). Be safe, have fun and go fast, in that order.

Hope this helps. PM me if you need specs for that powerhead.

[Dave M]

Good Advice

Build that old design and put a small outboard on it and play around. Also, there are a lot of kit boats and boat plans available today that are cutting edge race technology, and they are easy to obtain right now.

You have what was mentioned earlier, you can contact Marc Johnson for plans as well, he is on this website as a sponsor. I think he might even have a set of Craig Craft plans he might be able to copy for you, not too bad a design, and old enough to almost be vintage, yet still be a lot safer than that other design.

You have a ton of options, check them out. You want a laker to play with, you might pick up a good used current boat for well under a $1000.00. I see them on this site go for under $500.00 a lot of times. You might want to go with that as well.

Some other Kit and plans:
JDS Extreme
Scottcraft (Dave Scott) I think still does kits

I know I am forgetting a bunch, so maybe someone will fill in the blanks of all that is available.

[mercury400m]

wow u guys are so helpful thanks a ton. i guess i decided ill take things slowly move along with the hydro i have now because its worth something and i just dont wanna throw it out so im goin to start there.

so my question is does any one know were to locate a 2 bladed racing prop for a mid 70's 18hp evinrude?

[bh/]

...so my question is does any one know were to locate a 2 bladed racing prop for a mid 70's 18hp evinrude?

Most posters on here are, or were into racing, and although the Johnson 18 is a good motor, it was never used for racing. However if u have one, use it. Props for it would more likely be found on the Antique Outboard Motor Site.
Posting want adds is free.
www.aomci.org

[johnsonm50]

I read all of this thread and agree... that motors WAAAY to much with or without a race lower. weight, power, top speed- however you look at it.
If you tried that you might think a waterlogged stick o dynomite went off!
It seems that only Darrel said why tho. If you compare it to modern race hydros things like the distance between the sponson rears and the transom, the under side, the airtraps, the width, some things are subtle and some obvious.
I have a pal thats got a 50s era homemade hydro, it looks real good, then I got a retired modern race hydro and varios motors. The 50s hydro is scary-er in the low 40s than a modern hydro at 60+. Its hairy in a straight line, feels like it wants to stuff, waves get cut by the nose and feel like there gonna take yer head off and then.. it feels like it wants to roll if you push too hard in a turn. A wet ride for a hot dayfor sure. Im pretty sure the boat you have there would be even worse. If you want to go to the expense of building- build a great one. Good Luck, have fun be safe.

[johnsonm50]

wow u guys are so helpful thanks a ton. i guess i decided ill take things slowly move along with the hydro i have now because its worth something and i just dont wanna throw it out so im goin to start there.

so my question is does any one know were to locate a 2 bladed racing prop for a mid 70's 18hp evinrude?

Since the 18s geared to .571 to 1 as opposed to 1 to 1 or close a race prop on the higher pitch end would be best. For a 2 blade Id think 12p max and 11p max for a 3 blade. You would have to jack the motor up pretty hi to get the benefit and would need to be watchfull of cooling. Also the center of gravity will be a concern. Ive messed alot with getting fishing OMCs to go-fast and had some progress, so know this.. youll be workin on it more! lol. Props, you can find race props but theyll have a 9/16 or 11/16 hole with no pin slot so adapting will be needed.. If youve got the bug bad enough youll figure it out.

[L. Allen]

Whatever it is, I'm not buying.

[mercury400m]

thanks for your input johnsonm50 it really helps , here

http://cgi.ebay.com/ebaymotors/solid...QQcmdZViewItem

i think i found a prop on ebay not sure if its right yet but im still figureing out the specs looks promising. it also has the slot for the shear pin in the back. What do you think?

i love working on the omc motors i basically know the motors inside out. the 18 i have is mint condition barely 10 hours or more on it. it pumps water well .

[oldracer]

Make sure it's the proper rotation for the engine.

[johnsonm50]

Yes, rotation -your motors right and most race props are left. Ive seen debate over whether you can run in reverse or not. My opinion is no because the gearcase is much more beefed up on the forward gear. [probly a reason] Ive read opposing opinions tho. Right hand speed props are around, problem is everyone who wants a faster fishing motor also wants them.
Prop size..I think your 18 has a 5/8 or thereabout forward pinned [3/16] shaft [double check that] so an AB or C at 9/16 - prop would need to be reamed, a D at 11/16 would be too loose as is and would need to be bushed. At a wall thikness of 1/32-, that wont be easy. I wouldnt spend too much $$$ on this cause really a good stainless prop made for the motor might work as well, aluminum 2nd best and you could look into comprops [plastic].

[bh/]

Michigan Wheel made many props for the 18 Johnsons of the 50/60s. The one intended for a 300# boat is the AJC417, 9.25 X 12" pitch, two blade bronze.
2nd choice would be a SMC44 three blade bronze, 9X11".
The standard fishing prop is a 9X9, or 9X10, and usually of a 'weedless' design, not good for speed.
The AJC417 is NLA, and has been for some time, but were common, and can still be found. You will be lucky to get one for under $100 .
I am sure that an 18 on that S&M design, will give you all you can handle, regardless of what prop is on it.

[johnsonm50]

A 12p prop @ 5500 rpm @ .571 gears works out to 35.6 rpm so you might actually go 33with max efficiency. Id say plenty fast enough to get used to the boat with relativly safe results [not as safe as watching from shore].

[mercury400m]

hey guys wow what a day it was today... i dont think i've worked on so many antique motors in my life in one day. any ways good news is i ran the 18 today and wow she ran like a beaut. i also found time to firgure out exactly what year she is (1961) and the nice thing about those years were that u could adjust the high speed jet. any ways for the prop yes i could make it fit if i really wanted to but i dont know... so ill look for a proper one. one weird things i found out about the prop thats on it is that it isnt an origional prop but its pitch is 9x10 1/2 witch is kinda neat i think. btw i really apreciate that u guys are helping me on this older stuff.

ps. johnsonm50 are you going to send me those specs for the m400 for the quicky crossover?

[johnsonm50]

hey guys wow what a day it was today... i dont think i've worked on so many antique motors in my life in one day. any ways good news is i ran the 18 today and wow she ran like a beaut. i also found time to firgure out exactly what year she is (1961) and the nice thing about those years were that u could adjust the high speed jet. any ways for the prop yes i could make it fit if i really wanted to but i dont know... so ill look for a proper one. one weird things i found out about the prop thats on it is that it isnt an origional prop but its pitch is 9x10 1/2 witch is kinda neat i think. btw i really apreciate that u guys are helping me on this older stuff.

ps. johnsonm50 are you going to send me those specs for the m400 for the quicky crossover?

I think that was Trident

[mercury400m]

opps lol srry he he