Waking Up Laurel River Lake With a 1957 Kiekhaefer Mercury MK75 Six-Cylinder Outboard Motor 

Sure thing, glad you enjoyed it! Thanks for the comment and the support!

Nice! It's funny how you can remember that stuff. My family had ,mostly Johnson outboards years ago rather than Mercs, but in the same way - I can still remember the way they all sounded and smelled. Lucky for me, I now have the majority of them that I remember as well! I will say the the Mercury six cylinder engines have one of the baddest sounds of all though! Probably the loudest and most memorable of any from that time!

Ha, glad to hear!!! I literally could listen to video after video of old 2 cycle outboard engines (and motorcycles too). The only thing better is hearing and smelling them in person! I'll have to check out some of your videos. I think the a couple of the coolest old two cycles I've ridden on have been a Yamaha RZ350 and Yamaha Catalina 250 (that thing oddly enough, sounded almost like a Moto GP bike, was wild).

They certainly are 😍 Thanks for the comment!

Oh I bet it does! These motors sound super unique and are the coolest sounding outboards out there! I could listen to this thing scream for hours on end :)

Nice! 40 MPH isn't bad at all! That's all I can reach at most with the MK75 on the 15' Vagabond with a 17 pitch brass prop (19 pitch doesn't help, and hurts acceleration).

@@retro_grade thankyou, I tried to switch to a 13 pitch two blade, lost all ability to pop a skier, and no change at all in the top end, and lost a lot of mid range torque. Went back to the three blade 11.

Brian, I'm not sure that's me you hear - as this video was so far the only time I've been to Laurel River Lake so far! But, thanks for the comment! This motor does sound good as well for sure :)

@@retro_grade good deal, someone is running a mean outfit down there in the summer.. you'll enjoy the lake, it's beautiful..

Ha, yes it is! Music to our ears!

Thank you! Glad that you enjoyed all of it!

Thanks Carlos! That's funny that you say that. My family still has my great grandfather's 1957 Alumacraft Queen Merrie up at our cabin in Ontario Canada, and they used it as the main boat to fish out of for years up until the early 2000's. My brother and I played underneath the front hood while my parents fished all day - only that boat had alot more room!

I have 2 merc 700's. One is black but originally white. Wasn't going to argue when it was free. 120 # compression on all six using a MERCTRONIC gauge

Glad you enjoyed it!

Wow, you can't argue with free at all, screamin good deal!!! I'm pretty sure my MK75 reads 120 psi across all six, at least last time I checked using the original Kiekhaefer gage. I actually also just bought a Merctronic gage for checking the timing and dwell also.

@ADDvancedGarage - thanks! I honestly hadn't really planned on even posting the footage, I was more expermenting with getting video and sound on the GoPro while out at the end of the year on her. Then figured what the heck. It's a great combo - I drove 8 hours or so south to pick it up and sold my smaller Feathercraft model aftewards. The PO had already done a great job with the overkill transom reinforcement. It's basically what I always wanted to try building - a MK75 six cylinder on one of those tiny racey looking hulls. Not as fast as one would figure it'd be (40 mph at the absolute most), but super cool and sounds fantastic :) Thanks for the comment and compliments!

She'll go about 40mph or so! Feathercrafts were pretty much made from suprlus aircraft grade aluminum left over from WW2, so your assement on it looking like an aircraft tracks! It helps to have a good polish as well of course....and I actually used the same buffer and polish as used on airplanes and airstream campers, LOL.

She looks like a boattail bullet 😊

Thanks, it certainly is!!!

Thanks, glad you enjoy it! It's defintiely a finely tuned peice of engineering wonderment :)

@zoeyshoots - the funny thing is I didn't even think that video would perform that well and posted it at the time to try to get something up. It's performed better than most others that I've put far more effort into. I could listen to old outboard motors run for hours upon it, so it seems that we have something in common :) -Brock

Thanks!

Thanks! I recently just bought a couple of project MK78A's, and have a couple of KG7H Super Hurricanes as well. But, you are correct - six cylinder direct drive Mercs are a world of their own :)

Thanks! I haven't hit a dock with mine yet either! But, in all fairness, I'm sure we have a little bit better batteries than they did back in 1957 too :)

They do all have a rare sound! I remember when I was a kid, hanging at my grandparent's place on Johnson's Island, Lake Erie, I learned really quick what a black six cylinder "Tower of Power" sounded like from off in the distance. (They have a bit more of a whine to them I feel like). At that time in the 1990's, seeing a Mercury six cylinder around or over 100 HP was pretty common, much more than it is now. As you said, it's getting to be a rare sound. Which is sad, because it's the BEST sound!

Yep, that's the way they run! You can briefly see me start it into reverse at the end of the video. On one hand, it adds a bit of complexity with reverse starting the engine - however, on the other hand it simplified the gear box and you don't ever need to worry about the clutch dogs wearing off!!!!

Thanks, appreciate it!

Thanks!

😂

Nice! They are very unique engines and while they are a bit more complicated in their own way, they certainly have other simplicities with not having a forward/reverse dog clutch to go out in the lower unit. I abosolutely love running mine around the lake.

Thanks for the compliment! It's a fun boat!

They were simple as well - as big of a black eye as the "dockbusters" got, they had no dog clutch or shifting mechanism in the lower unit to fail. Check out the "50,000 miles by outboard" testing they did on them :) ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qfNL32sZvvA.html

Thanks, appreciate the support! This is hands down the coolest motor I've had! Love it

I would LOVE to have a boat with two towers of power mounted to it!!! This is correct LOL. Thanks for the comment!

It certainly is, and like none other! All of the 'Towers of Power' sound fantastic. I haven't had one of the 1970's ones yet but hopefully someday I'll acquire a boat where I can run those as well. That sucks that it eventually gave out, but I'd say 30+ years of use isn't terrible either. Try getting that out of any of the newer outboard motors manufactured today, I'm guessing that won't happen. But time will tell :)

That can be fixed

Glad to hear there is someone else! I debated posting that long of time without anything to break it up, or posting it at all, but figured somebody might enjoy it :)

She certainly does Greg! Love the comment - currently reading Iron Fist by Jefferery Roedgen. Kiekhaefer was a very interesting character 👍

Exactly she was the standard in her day. Kirk underrated power in his mercs this was closer to 88 hp a lot of power attached to such a small vessel. Sounds is a symphony on fresh water.

Well worth it 🤣 You are correct, no other motor sounds like them. Especially in the little Feathercraft with that motor directly behind the operator LOL.

Thanks, glad you appreciate them like we do!

I think it's more like 24:1 - I basically mix the exact amount stated in the owners manual. Thanks!

1qt 30 weight motor oil to 5 gallons of gas

Hah, good way to describe it!

Thanks!

Thanks! The pistol grip throttle used on the earlier direct-drive Mercury engines is (in my opinion) one of the coolest/best looking controls of all time!

Yes they do!

Thanks!

Thanks! Lake life is certainly where it's at :)

Nice! I'd like to have a 1970's Tower of Power as well on an appropriate ride if I ever come across one at the right price and time. A sidewinder would be a suitable fit for sure - those are really cool looking rides :)

@@retro_grade I used to torment a couple of other guys that ran v4 140hp OMC's on their boats, one a 16' Sidewinder the other was a 16' Checkmate. I always had about 5 mph on them.

There was no 1400 in 73, it was a 72 or a 78, and they were two totally different engines, except for Displacement. In 73 there was a 1150 and a 1500. As for exchanging a 140 powerhead for a 150. Exhaust Tuning was different, so the 150hp wouldn't be attained. Even if it was, it is only a 2mph difference

@@pjimmbojimmbo1990Thanks for the info I wasn't aware of this. I bought the boat/motor used so I guessed that it was a '73 due to the blue banding. I thought the '72's had red banding?

@@pjimmbojimmbo1990Thanks you're right it has to be a 1972. I thought the 72's & 71's were red and mine was blue but I looked it up and the 72's were blue. Many thanks.

Yeah, I think they are AJ model carburetors. But, you can still see the fuel spraying when that front cover is off :) I bet that megaphone exhaust speaks to the whole lake!

Screams (maybe sings) is the only way to describe it that sound!!@@

Man, these are starting to become tough to find parts for. (Points, for instance, are NLA and approaching 80 bucks or more per set). Other than Ebay, try these: www.moparmall.com/category-s/279.htm www.johnsmcintoshvintagemercuryoutboard.com/ www.marineengine.com/ www.vintageoutboard.com/collections/mercury-other-engine-parts www.oldmercs.com/ Marineengine.com is good for finding part numbers off the diagrams to use for Ebay. (And, they have a few parts on there also). I just bought a MK78 that's rough and am looking to get another one, and will be going through more of the same soon LOL.

Hopefully! 😀

It's premix (oil injected didn't come out on outboards until the 70's or 80's I think?) - I'd have to look at the original manual that I always refer to when mixing it, but its around 20:1 or 24:1. Those old motors ran pretty rich on oil - old Johnson/Evinrude outboards, for instance, ran on 16:1. I typically run Mercury Quicksilver two cycle oil, which is a good middle of the ground oil readily available at Walmart of Academy Sports. But any marine rated TCW3 oil is honestly fine. Heck, back in the day they were using standard 30 weight motor oil and only later started coming out with actual two cycle oil for those engines. I actually have a letter from Mercury Motors to my great grandfather in the late 1950's, telling him that running their improved Quicksilver two-cycle oil in his Mark 55 would solve the problem of varnish and carbon deposits on the top of his pistons that he was apparently getting from running standard 30 weight. Some day, I need to find it a make a short on that :)

Yes it is, and it's fantastic! (The transom has been heavily reinforced to accommodate it).

A Mark 30 would be more typical on that boat, and a Mark 55 would be sort of a hot setup.

Thanks, appreciate it! Honestly, it was taken pretty quickly while I was on fall break with my wife and kid, and I wasn't even going to post it at first. Was just playing around seeing what kind of footage and sound I could capture, then decided to put something together. I'll have more videos on this boat and motor in the future. It's a 1953 Vagabond (only year made with that center steering configuration in the rear that looks like that). It's actually a 60 horsepower mercury....the Mark 78 would be a 75 horse. I'm actually trying to find a decent one so that I can mount it up and see if I can push it even harder. I wouldn't personally mount a motor like that on your Vagabond unless you heavily reinforce the transom, like the previous owner did on my boat. He basically had 1" thick wood all the way down on the inside, and then sandwiched two pieces of 3/8" thick aluminum plate, cut out to the exact barrel-back shape of the boat, on either side. The transom height was also raised a bit as well to accommodate the larger motor....although it's high enough it nearly cavitates the prop. However, it it hadn't been raised, that motor weighs the back of the boat down so much, it'd likely sink it lol.

@@retro_grade it would be fine, its got a one inch thick pc of mahogany on both sides of the transome. The outer board goes from top to bottom and the inner from one side to the other. The boat is rated for 40. And technically its pushing the same amount of weight to plane. Doesn't matter anyway lol. No new motor in the cards for my boat until the old 20 quits. But are you sure thats not like a feathercraft firefly though?

@@shornandkenny - nope, it's a 15' Vagabond. Firefly is REALLY small (9' or so). I actually want one badly. There's one currently on Ebay I'm having a hard time resisting purchase of :)

@@retro_grade buy it! And yes, the vagabond with the center steer in the rear seat is extremely rare. Ive never actually seen one and ive read and watched everything feathercraft. Grew up in the 80s on lake huron on offshore boats but nobody can afford that anymore so i like my feathercraft, even with the 20 on it it flies with the boy and i in it.

@@retro_grade I had a hard time resisting the purchase of Marshall's boat. You are making better use of it than I would have. That is way too much motor for me.

Thanks, glad you enjoyed it!

I'll have to check and calculate - every time I mix fuel for it, I pull the amount straight from the mercury mk75 owners manual

@@retro_grade Yeah no worries, I asked because I saw somewhere it said 20:1 but that seems like an awful lot of oil, especially with modern oil. I'm thinking about possibly picking up a MK75, hence all the questions. Thanks.

@@harisguhdija9734 - that's not out of the ballpark at all - the older engines ran rich on oil. Old OMC outboards run at 16:1. I want to say that 20:1 seems right for that off the top of my head. I actually just looked - the original manual calls for 12 ounces of Quicksilver oil per 2 gallons, or 16 ounces of SAE 30 per gallons - that works out to roughly between 20:1 and 16:1 ratio. I go off the two-stroke oil spec, so I'm running 20:1.

Between 35 and 37 mph. Unloaded and trimmed right, 40s about all I can make with it

Looks good, seems to run well, that's a nice cruise speed, different props perform differently at different rpm on these old motors--you have a nice rig with a classic motor that moves smoothly on the water--enjoyed the video, thanks

@bethcrities9435 - surprisingly, it's dead on....can't even go an inch higher on the transom. The previous owner paid a friend of his who sets up and races hydroplanes and such to reinforce and raise the transom on the boat when he owned it. At its current height, if I take a hard turn while having it set to the proper trim for max speed, I'll start to cavitate the prop. It will also cavitate on the rare occasion that I ever have the boat out on rough water. This MK75 is the short shaft configuation, not long shaft.

Hah, I consider that a good thing! I love listening to that motor screaming into my ears. But yes, most of the old Mercuries at that time were louder at wide open throttle, as Kiekhaefer didn't put intake silencers on them like OMC started doing (around 1955 I think?). Even the MK55's are fairly loud when you're running them at full throttle.

So loaded down with gear, wife, and kid, she'll do about 35 to 37 mph. That's also keeping the trim adjusted to give her a smooth ride. With just myself in the boat, and the trim on the next setting to bring the nose up a bit, I've hit 40 mph with her. But, it's not as smooth, very light in the front, and bouncy. In addition, the prop will cavitate making hard turns at that setting (due to the raised transom). This is all with a 17 pitch prop. A 19 pitch would slightly lower the RPMS, make it slower to take off, and lose a couple of MPH. What you are guessing is what I was hoping the boat would go when I bought her :)

That’s still not bad, and I don’t know of anybody who runs full out for more than a few minutes at a time. I think the fastest I went on water was around 50, and being out in the open it feels like a hundred and fifty.