[Texas Thunder]

Howdy folks, I'm looking for some input and direction from you experienced Mariah owners.

2 weeks ago I came across an elderly couple selling their Talari 220. The boat was being used mainly for sunset rides around the lake. Due to knee issues he was no longer able to step into his boat and was selling to buy a pontoon for he and his wife. He's owned the boat for the last 11 years and the last time it was serviced was 3-4 years ago.

The boat was kept in his covered back yard slip and was raised out of the water after each use. I inspected the outdrive once out of the water and it looked great with no corrosion or pitting that I could see and a stainless Vengeance prop. The interior is perfect, engine and bilge are spotless for a 20 year old boat.

I went for a test drive with him and everything went well so I bought the boat. Only issue was an inop speedometer. I drove it across the lake to get some fuel and played around on the lake for an hour or so before parking it. I got a great deal on a new tandem trailer with 4 wheel disk brakes from Bass Pro in Dallas so I drove from Houston to Dallas last week to buy it. On the way home the trailer blew a wheel seal and slung grease all over the rotor and inner rim of the wheel. I called the Houston Tracker dealer and made arrangements to get it there last Saturday to have it fixed under warranty. I'm still waiting to get the call to pick it up.

Last Sunday evening I went down to the lake to put some anti ethanol fuel treatment in the tank and thought what the hell, I'll take it out for a bit. Once out on the open water it drove and felt fantastic. Water was like glass and all was well. Due to the speedo being inop I decided to use my phone GPS to get an idea as to how fast I was going because it seemed like I was really clicking along. Once everything was setup I got up onto plane and made a left hand U turn and started to feel a shudder coming from the back end. Quick look at the depth finder said that the water was 41' so I ruled out hitting something submerged. Once I straightened out everything was fine. I slowly advanced to get up on plane and trimmed up a bit and everything was fine. I advanced to WOT and about 5 seconds into it the engine began to over rev and I was losing speed. I could now smell burning rubber coming from the back of the boat.

I went to idle but couldn't see an obvious source of the smell. I opened the engine compartment and everything was fine. Engine was idling perfectly. I closed it up and put it into drive again. As soon as I added power the engine would not drive the boat and would over rev. I was able to get it to give me no-wake speed and limp back to the temporary boat slip I was borrowing from a buddy until the trailer comes back. I kept a watchful eye on the engine temp because I was worried about overheating due to the raw water pump being compromised with low propeller RPMs. It never got over 150.

Doing some research, I've pretty much come to the conclusion that the engine coupler has spun due to the smell of burning rubber, and most likely due to the lack of annual maintenance. So, with less than 2 hours on my "New boat" I'm going to have to pull the engine to replace the coupler. Murphy has shown his ugly head and this is the hand I'm dealt.

I'm an old school motorhead and spent most of my youth drag racing my 69 Camaro so I know my way around cars, engines etc and do all of my own automotive work. I've pretty much cut my teeth on that 350 Chevy motor. I have an assortment of real man hand and pneumatic tools. I now have another "winter project" so I'm in no rush.

Besides the coupler and shaft, I'm thinking gimbal bearing, bellows kit, raw water pump, tune up, belts, hoses and some service manuals.

Engine is the 5.7 Magnum with Alpha One Gen II sterndrive. I have everything that came new with the boat including brochures, promo materials, Mariah owners manual, Mercruser operators manual, trailer manual etc.

My question is that since I'm going in that deep what else should I replace while I'm in there? What pitfalls should I watch for and any heads up's would be appreciated. Also, when it comes to Marine parts what brands are considered heavy duty or high performance and who are reputable sellers? Also what specialty tools are needed or work arounds to get those things done. Is there anything Mariah specific that might help or hinder me?

Your input is much appreciated!
~Joe

[Hudson River Steve]

Joe,

Aside from the parts you already mentioned you might want to check and replace a few other items while the drive and engine are out of the boat.

Check the lower shift cable and operation of the bell crank on the alpha drive. If they are stiff at all you might want to change them now while you can get to them. When they get stiff it causes the engine to cut out and stall when shifting gears. You want them to operate without any resistance.

You should also carefully check the wiring and operation of the trim sender and limit switch. They can only be changed with the drive off. With the engine out it will be a snap.

What is worrisome is why did your motor coupler give up the ghost???
Are there any marks of a strike on the prop? Was there any evidence of rope or fishing line tangled between the prop and the drive? When you pull the drive, check if the gimbal bearing is seized. If none of the above were the cause then I would suspect alignment between the motor and drive. Make sure you purchase or borrow a Mercruiser alignment tool when reinstalling the motor. The alignment must be perfect, especially at high RPM's.
Something put excessive strain on the drive train to cause the coupler to slip.

Steve

[Firestone]

Welcome to the club. Wow you have had an adventure with your boat already. Speedometer are based on water pressure and are problematic due to debris getting in th opening on the outdrive. I just use my phone as well. Hudson River Steve is the bomb and I would follow any of his advice. Well you blew the trailer and have engine trouble so those are out of tge way for smooth sailing on these great Mariah hulls. Love to see some picks

[Texas Thunder]

Steve, Thanks for the reply. I will definitely look at those things you mentioned.

I have read numerous forums saying that the most likely cause of the failure is that the shaft splines were not greased properly or at all. I've learned that the drive needs to be removed annually to inspect the splines and get re-greased. I'm also seeing after market couplers with grease fittings so you can grease it without having to pull the drive. Nearly all of the failures were from lack of maintenance and one boat mechanic said "sometimes 20 year old boats have parts failures". I won't know for sure until I can get the boat out of the lake and get it home. I can't see the prop because it's still in the water. Even with it trimmed all the way up the prop is still submerged.

What's the reputation of Mallory Marine and GLM aftermarket parts? Back in the day I ran Mallory on my hot rods and they had a great reputation. I'm looking for something slightly better than stock and don't know who's got what in the marine world.

I appreciate everyone's input.
~Joe

[Hudson River Steve]

Joe,

I don't think you need to grease the splines every year. I'll go 2 and sometimes 3 yrs without removing my outdrive and greasing the splines and have never experience any issues. I bought a tube of Merc Spline Grease p/n 92-802869Q1 many years ago. You need so little of it I will probably have it forever. It tends to stay in place really well.

I doubt you will see any performance increase by using a Mallory distributor in place of your stock distributor. Your motor most likely has a Thunderbolt ignition which automatically advances the timing for maximum performance based on feedback from knock sensors. You may actually lose performance if you change it out for an aftermarket distributor.

I've heard mixed opinions of GLM manifolds, not really sure about their other parts, I usually use genuine Merc parts. I am running a GLM raw water pump on my 7.4 MPI. I only installed it this year as I was fed up with the lousy reliability of the stock Merc pump. My initial impression is that it is a big improvement over stock but time will tell.