New Midsection for 850CC

[OUTBOARDER]

Well in the pursuit of simplicity I am trying to make something that is easy to fab and use for a boat with a 8 1/2" Transom................

The thrust rod using a piece of hex stock drilled and tapped LH and RH for
LH and RH Threaded rod ends seems desireable.
A jam nut can be backed off the rod end and the hex stock turned to adjust the trim. All done without having to hold the engine while turning stuff.

Will have to :

Drill and tap 1 1/4" Hex for 3/4-16 LH and RH threads.

Powerhead Base Plate
Gearcase adapter plate
Cut old fishing mid down to 4"

Mount brackets from 5" X 5" x 1/2" aluminum angle
cross plate from 5" x 1/2" aluminum
thrust blocks from 1 1/2" x 1" aluminum

Swivel / Tilt tube 2.5" x 2.5" x .25" sq tube
1.5" OD x 1" ID steel tube
4 Flanged Brass Bushings


Anthony

[BRIAN HENDRICK]

A;
-is that boat your 'old' Apel???
-what does that threaded dowel do?[must be the prop shaft, level with bottom?]
-why bother with a 'fishing mid', just cut some plate
-I wonder how stiff it is torsionally,
ie; side loads from the prop.

It is time for a simple, light, strong, functional mid.

[brichter]

Outboarder...
What modeling program are you using? Is it inventer?

Instead of the fishing mid, use an old 5" driveshaft housing extension, they're cheap and easy to find.

[OUTBOARDER]

I wanted to hang bottom carb about 2" above transom.
The Inventor model shows total weight of 35lbs with height at 5" from baseplate to gearcase mounting surface. The lateral rigidity will be accomplished by sandwiching the powerhead baseplate and gearcase plate
with 3/4" bolt in front and 1/2" bolts in rear.

The 5" spacer would be great but the outboard salvage place in VA sold all the stuff outside for scrap and raised prices for the junk they kept. I have the mid with a nice 4" tall section at bottom that already has the 45 gearcase bolt pattern.

If you have some pics of some mids put them up would be interested to see.

Thanks,

Anthony

[mac19f]

Unless you have a thrust socket for the gearcase this tower will be very springy fore and aft due to the shallow angle of the kickout adjuster. Unless the body fit of the bolts in the adjuster and the swivel pin are very tight there will be, as Brian suggests, a good bit of twist of the engine about the boat centerline when the engine is steered.

[David Mason]

You might want to look at some of the pics of Lee Tietz mids and also a Harrison Mid. Both are top notch and just might fit your bill nicely. I think 35 pounds is pretty heavy for a mid, but if weight is not a concern on balance of the boat it will be fine. I believe Tietze mids are a lot less than 35 pounds, but I might be mistaken. If you need any contact info for these I can provide.

Nice looking model though.

If you are concerned about the 8.5" transom, you can raise that up fairly easy, and a lot cheaper than fabbing a tower. My transoms are around 10" and I still run the Merc clamp brackets and more recently the 35HP OMC clamps. Both offer spots to bolt your engine to the transom once you find final spot to race at with your testing.

[Tim Kurcz]

Hey Anthony,

Your approach looks great! Simple and beefy is good - I'm likewise concerned about the shallow pitch adjust angle. Here are close images of my improved Parker which weighs in at 32-1/2 lbs including foldable steering bar. Hopefully there's something in here which might help. Features are:

1) Readily available conventional Merc clamp & swivel with 5-1/2" choke (retains factory grease zerc).

2) 45SS style horizontal pitch adjustment uses 3/4"-16 thread just as you have selected. Allows 16 through 20 degree transom angle.

3) The lubricated (grease zerc) 6061 T6 thrust yoke is the lower pivot.

4) The thrust bracket bolts into existing Merc features and free floats.

5) Tower structure is laser cut tig welded PNO steel, a grade about half way between 1018 and 4130. The pivot tube is 4130.

6) A precision welding jig delivers driveshaft centerline accuracy to +/- .003" The tower and thrust bracket are powder coated.

7) Stressed, open structure allows easy access to powerhead and gearcase attachement hardware and cooling fittings.

The only downside for any fabricated tower is the time involved to make one. The first one was about 80 hours design and build. Laser cutting of features (including holes) and construction of a welding jig (about 8 hours) brought production down to about 20 hours each for the 7 built this winter. The good news is they should last 35 years or so!

The 7-1/4" tower in the images is available for immediate sale ($1150 + shipping) and includes gearcase fasteners in case any are interested. I've also got one 10-1/4" available with enclosed exhaust (see "Evil twins").

Otherwise, good luck with your build. Please continue to post images of your work - it is always very nice!

Tim

BTW: In case you're wondering about the two extra front holes - they and the steering bar attach holes are extreme corners of the superimposed 45SS powerhead bolt pattern just in case!

[OUTBOARDER]

Hey Anthony,

Your approach looks great! Simple and beefy is good - I'm likewise concerned about the shallow pitch adjust angle. Here are close images of my improved Parker which weighs in at 32-1/2 lbs including foldable steering bar. Hopefully there's something in here which might help. Features are:

1) Readily available conventional Merc clamp & swivel with 5-1/2" choke (retains factory grease zerc).

2) 45SS style horizontal pitch adjustment uses 3/4"-16 thread just as you have selected. Allows 16 through 20 degree transom angle.

3) The lubricated (grease zerc) 6061 T6 thrust yoke is the lower pivot.

4) The thrust bracket bolts into existing Merc features and free floats.

5) Tower structure is laser cut tig welded PNO steel, a grade about half way between 1018 and 4130. The pivot tube is 4130.

6) A precision welding jig delivers driveshaft centerline accuracy to +/- .003" The tower and thrust bracket are powder coated.

7) Stressed, open structure allows easy access to powerhead and gearcase attachement hardware and cooling fittings.

The only downside for any fabricated tower is the time involved to make one. The first one was about 80 hours design and build. Laser cutting of features (including holes) and construction of a welding jig (about 8 hours) brought production down to about 20 hours each for the 7 built this winter. The good news is they should last 35 years or so!

The 7-1/4" tower in the images is available for immediate sale ($1150 + shipping) and includes gearcase fasteners in case any are interested. I've also got one 10-1/4" available with enclosed exhaust (see "Evil twins").

Otherwise, good luck with your build. Please continue to post images of your work - it is always very nice!

Tim

BTW: In case you're wondering about the two extra front holes - they and the steering bar attach holes are extreme corners of the superimposed 45SS powerhead bolt pattern just in case!

Hello Tim,
I am on a work assignment in Charlotte NC, havent looked at a shop yet to work out of, so am not sure about how much I will do myself???
Last mid was a hustler/Bass/made my own stern clamps.

The boat I found has a 8 1/2" x 30deg transom and I wanted to hang bottom carb about 2" above transom. I have a 45ss gearcase w/waterpump.

Your mid looks nice I wonder what a 4" would be like???

Anthony

[Tim Kurcz]

Wow Anthony,

The 30 degree transom angle is a problem - you have to build custom. There's no outboard clamp & swivel I know of that will work. Let me know if you're out of shop. I'll gladly carve some aluminum for you.

Tim

About the 4" - the #3 would be in the water. Would need a top outlet exhaust without a drain hole!

[hydroplay]

Cummon, Tim, do it better. You have a beautiful and sturdy box shaped housing and then use a decrepit looking Merc clamp assembly? How about at least bead blasting it to make it compatabile with the rest of the tower?