Chris Chamberlain's Wetback

[mac19f]

That engine has had some major modifications. I own 2 Mk40H's and a stock Mk40. Neither the Mk40 nor the MK40H came with a tiller handle. The rewind appears to be cut from the top of a "turtle top" rewind such as a Mk55.
The tower housing appears to be a graft of the lower portion of a D quicky tower and a stock Mk40 tower to lengthen it...OUCH!

BTW: I have reproduction cowling parts for KG9-1 and Mk40 engines.

[Mark75H]

The foot is also modified ... Mk40H style water inlets with Mk55H style skeg.

The whole thing is modified to be used on a much taller/larger boat than you are building

[John (Taylor) Gabrowski]

The motor is a Mark 40 Merc alright. The height of the tower is a "Q" longer length with some "quiet down" built on provisions. The exhaust is supposed to be water level at the bottom big spout. Some one welded on an addition to put the exhaust right into the below water level stream to quiet the motor even more. To make it more original cut that downward snout off to where it is supposed to be water level to perform better and sound better too. Also where the top spout is, is just supposed to be a very short brass outpipe just to relieve exhaust pressure when the engine starts in the water, the main spout takes over once your off.

Some one lengthened the skeg a bit to make it more 55Hish and that gives it better control on a hydro. Stripping the paint off the prop, with sharpening its edges and polishing it will sure improve its performance though it might not be much of a hydro prop. It could be a silk purse from a sow's ear!

Of the 2 Merc 40Hs I had one on 40H on a "H" short tower with opened exhaust plate on the block and Hubbel reed valves installed and we ran it on a Ben Hur hydro back in the early 1970s and she went real well. Not one spill in her day and she ran in the mid 60s miles per hour and she sounded just Grreeeaaat!!!!! Kinda deafened your left side a bit though and upset some neighbours but she was a racing engine!!!

[mac19f]

Definitely not a "Q" tower. Look a the extension of the swivel bracket and the lower swivel pin bushing area. A "Q" tower has the lower swivel bushing in the same place as an "H" tower but is longer between that and the cavitation plate. Looks like this engine has had a new lower swivel bushing boss welded in.

[John (Taylor) Gabrowski]

I took a few looks at Q towers from pics and that one looks kind of a homebuilt version at a Q length it seems. My hats off to the builder and an "A " for effort in trying to do something similar. That takes some imagination, lots of effort and some knowhow.

[Healey75]

Thanks for your help and all your comments re the MK40, I was all set to build a rig around the engine but now I don't know what to do with it! I'll bung it in the corner and have a think... I agree the work done to mod it has been carried out to a really high standard and as it stands you can't see it's been done, it all looks as if it's a production job..oh well.

It's a shame , since basically it feels a really good engine without any slack or gravelly feel to it, even the gearbox feels up together, the whole thing is cosmetically challenged for sure, but it's just a mongrel, but then you can love a mongrel!

Thanks again, all the best...Steve

[John (Taylor) Gabrowski]

That Mark 40 Merc motor is mean't to be cleaned up nicely and run on a nice hydro. Its NO mongrel!!! They were the runners of their day and readers around here them. Where they are deficient people find the correct parts over time, restore and run them. There is help out there with possible parts leads to help. Nothing wrong with building the hydro and restoring the engine at the same time and running it, proving out what you are doing.

On some threads here on BRF a reader rebuilt a Merc 40H to a 44 cubic inch displacement, modernized the combustion chambers, with Tillotson KC6 large bore carb upgrades and with all that plus trying to make it look the year it is based on goes 80+ miles per hour and that is just its infancy in coming back. Now that is mixing up the old with the new and you don't have to go that far to have fun and enjoying what your doing. Don't sideline it with too much thought, get on with a Wetback or Ben Hur for her and get at it!

[Mark75H]

The altered mid section is a mongrelization, that's why he's down. Maybe you can't see things the way everyone else does.

[John (Taylor) Gabrowski]

KG9 and Mark 40 towers were known to be thin and at times the aluminum brittle. Seen and had so many of these towers crack welded, braced and welded from 3 sides to the extreme and were still proudly used. Comparing to some towers seen that one is a good start to something not bad at all. It depends what your use to. I see a silk purse out of a sow's ear that would dishearten most only to work on it and turn it into that silk purse. I encourage even in the face of adversity. Its percevearance.

[Healey75]

Thanks for the encouragement...it worked! spent the day thinking on it, and you're right it deserves to be restored and run, I have quickly stripped the paint on the leg to try to find out what I've got...see the picture attached, between the arrows the leg has been cut and extended, you can just make out the welds in the photo, it's been done well. There's no welding that I can detect at the moment lower down, I'll get to with the paint stripper again in daylight, I think it's the casting where its been cleaned up BUT the detailing around the pivot bearing is different to the picture I have of a Mk40H, the bottom pivot bearing on mine is half way down the exhaust outlet (it should be above?) and there is no streamline plate below the pivot. So still a mystery...but it's a MK40H..it says so on the badge! and the serial number checks out, I know it could be a badge from a genuine engine but it will do for me!

I have decided to pull the engine down just enough to see what state the drive shaft is in & how has all it been modified etc, then depending on what we find would look to cut and shut the leg back to an H tower height, if for any reason this can't be done I'll leave it well alone apart from a mechanical overhaul as required and get on with the project.

Hopefully we will have the mods completed by mid December, I'll post something to update you all

Thanks again, regards, Steve