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Knightnight

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84' Keaton 18-J
« on: October 06, 2021, 11:40:51 am »
First up, thank you everyone for your help so far, I really appreciate it.

Boat: 1984 Jack Keaton 18-J
Engine: Ford Hardin Marine 460 (7.5L)
Pump: Berkeley 12JE with place diverter

Backstory:
My father-in-law purchased this boat new in 1984 while living out in California. He has had it ever since for rec skiing/boating purposes. He is now retiring to FL coast and the boat is not a salt-water boat. He has graciously given the boat to the my brother-in-law and me. When I received the boat (2020) it had 290 hours total. My father-in-law indicated the engine was rebuilt about ~50hrs ago (unknown specs of internals/changes/etc though) as one year he forgot to winterize and ice caused internal damage. After the rebuilt, he used it for a year or so and then the boat sat for 7-8 years as the kids went off to college.

Today:
Thus here we are today where I am trying to get the boat back into run-able shape to enjoy once again as my wife and her siblings once did. I have never worked with a large carb before, distributors/timing, any big block engine, or any real jet pump besides jet-skis. There isn't that much data on these small batch boats in terms of diagrams/etc but from reading on here it seems most of the boats of this era were relatively the same which has helped a lot. The name of the game in terms of trying to get this boat back operationally reliable has been see if anything is salvage/rebuild able. Unfortunately almost everything so far has been replace with new (which can be hard to find replacement marine rated parts for such old engines/boat) which I guess is given on something almost 40 years old...


Engine:
Ford 460, I have no idea what was replaced during the rebuild, cam size, etc. For all intents and purposes I am assuming stock hardin marine 460 rated at 320hp at 4600 rpm (8.35:1 compression). The engine is in a enclosed engine bay with through transom exhaust, so no large blowers/open air headers/etc are in the future. This is mostly just a rec ski boat. Intake is a edlebrock dual-plane (not sure if factory or not), exhaust is factory.

Carb:
I went with a Quick-fuel M-600 CFM (4160 Holley basically with vacuum secondaries). When I received the boat it had a Holley 670 4150 street avenger carb. You can guess how well they lasted in the elements and from sitting. I at first was thinking I would just rebuild it and add some J-Tubes but the metering blocks were cracked and the body had internal cracks. Some might argue the 600 CFM is a little small but I plan on keeping the 460 mostly stock and at only 80% efficiency at 5000 rpm which most calculators suggest ~570CFM, 600CFM seemed fine. I am still learning all the tuning dynamics, luckily the quick fuel make is a little bit easier than stock holleys.

Ignition:
It had the original distributor on it which had a pertronix ignitor on it that replaced points at some point but I realized later the shaft, bushings, springs (unknown specs) were worn and decided to just buy a new one. I went with a pertronix 3 distributor which also a rev limiter to help with any over-reving if air-borne. Currently running 12 degree at idle (~950 RPM) and (12+20) mechanical advance only all in 32 degrees at 3000 rpm. I may try to push this to 34 degrees. Surprisingly the manual says to run 40 degrees full advance at 4000rpm but that was during leaded gasoline days and I am afraid gasoline these days isn't up to same standards and would ping at that much advance. I replaced plugs and wires of course, gapped them to .045", factory spec is .035" but distributor says I could gap them +.010" higher. Seems to be running fine.

Fuel Delivery: I was able to run the boat fine on a water hose on the trailer, took the boat out for its first maiden voyage in 7 years, boat ran like crap. Come to realize the factory molded body in fiber glass tank was leaking and had a ton of crude/water. Luckily I put a on a new fuel-water separator and some in-line filters which minimize crud to the new carb...I did end up taking new carb apart to clean it out and replace some gaskets as safe measure. I ended up having my father-in-law friend custom fab a new aluminum 27 gallon fuel tank (original was 30 gallon). Once I installed the new aluminum tank (I used composite anchor ports to hold it in place rather than fiberglassing it back in), replaced fuel lines (3/8 A-1), new fuel gauge/sending unit, filters. Still running original carter mechanical pump, seems alright maybe a tad weak. Currently looking to find a replacement. At idle PSI is not steady but bounces between 3-5PSI, at rev, PSI reads about ~5.7 PSI.

Pump:
I am still running the original A impeller pump 12JE, I have no idea if it has been rebuilt or any service work besides fluids. I replaced the bowl fluid and some of the bowl seals but I haven't dug deeper into the pump. The impeller seemed to look fine with no major gouges or anything. I did install a new place diverter with hydraulic controls and a large rudder for low speed maneuverability and to assist with skiers who are more likely to pull the back end around without one. I modified the place diverter hydraulic controls to use two relays instead of their aftermarket diode kit which seems allows me to move the pump quick with up/down steering wheel mounted control.


I have been able to hit 5000rpm which seems a little high for a stock engine (I say this because horsepower chart for A impeller at 5000 rpms is like ~370hp) but I don't notice any cavitation. I was able to hit 65mph (GPS) at 5000rpm (I verified original tach is accurate with a digital backup tach also). I didn't really expect to hit 5000rpm so maybe engine isn't stock or pump tolerances are slightly loose.

Body: Replaced steering, throttle, and bucket cable. New steering wheel, new rear-view mirror. The floor was rotted and foam was water logged. I ended up having a local shop rip out the main floor section, that stringer section and floor replaced with composite and re-foamed. Cutting out the molded in fiberglass tank I did myself and a even a little bit of fiberglass work attaching composite anchor points for the new fuel tank. I was surprised to find the molded in fiberglass tank was literally part of the body, not extra liner or anything...Overall the paint is original and okay shape (lots of heat/spider cracks but she looks pretty good from 10 feet away), I may vinyl wrap the boat at some point vs cost of new gel-coat. Back bench needs re-upholstered in one spot but for now the seats are good enough. I did rip out the original carpet and plan to replace with new carpet once I get all the mechanicals in check, cosmetics last of course. This boat came with a factory pump cover that also serves as re-boarding step. The factory cover didn't fit the new diverter linkage/support so I made some minor cuts/modifications to keep it still usable. Last I re-wired almost everything, added some usb charging ports, fuse block, new bilge, blower motor, and replaced all the lights with leds.

I know I wrote a book, but just wanted to share some of my experiences as a noob and first-time doing a lot of this. Pics below



« Last Edit: October 06, 2021, 12:16:45 pm by Knightnight »
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Knightnight

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Re: 84' Keaton 18-J
« Reply #1 on: October 06, 2021, 11:41:41 am »
Also an interesting old Powerboat Magazine review of this boat with the 460. I am already hitting 65 GPS at 5000rpm, father-in-law thinks it should go faster ~70mph maybe with the place diverter. I am not sure. Running 32 degrees of timing, I may try for 34 and see what she will do but I don't want to push beyond 5000rpm really, not knowing the internal specs of the engine.
« Last Edit: October 06, 2021, 11:46:08 am by Knightnight »
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FordLover

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Re: 84' Keaton 18-J
« Reply #2 on: October 08, 2021, 07:57:45 pm »
I always thought Keatons were cool clean boats. In my mind I think they are badass cruisers.  The fact that you are doing 65 is impressive to me. I did a couple river runs and there was a couple Keatons in the group and they werent doing 65. 

Sent from my LM-Q730 using SoCal Jet Boats mobile app

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Knightnight

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Re: 84' Keaton 18-J
« Reply #3 on: March 30, 2022, 01:24:20 pm »
Powerboat magazine hit radar 64 mph from the factory. This season I plan to run the smallest purple nozzle insert for the place diverter. Came with the red sleeve (medium size). Supposedly could pick up 3-5 more mph (Finnegan did with a smaller one). I went smaller given my boat weight ~1800lbs dry and similar v-bottom profile as his. I plan to run back to back runs between the red sleeze and purple and will update later on true improvement.

https://youtu.be/HOKRH3mURZE?t=856
« Last Edit: March 30, 2022, 01:51:35 pm by Knightnight »
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Knightnight

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Re: 84' Keaton 18-J
« Reply #4 on: March 30, 2022, 01:47:27 pm »
Have been working on the trailer, new transom ratchet strap tie-downs (previously nothing before), new bow stop (still have factory bumper arms but may take them off, they are starting to rust and trap water in the tubes, tried cleaning the drain holes but they are all eaten up inside), and replaced the 40 year old sagging leaf springs (removing the old bolts was a chore to say the least)

Also rebuilt the factory carter marine pump (you can see old diaphragm was cracked, lucky it didn't rupture before I rebuilt it). The rebuild kit was from then and now automotive, super helpful guy.

« Last Edit: March 30, 2022, 02:00:36 pm by Knightnight »
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