'73 Merc 500 50 hp

[JReynolds11090]

Hey guys, I've recently been given the pleasure of being able to try and get one of my grandparents old boats back in the water. Its an old '77 15' Tomboy bass boat with a '73 Merc 500 50 hp thunderbolt motor on her. I threw some new spark plugs on her and hooked a battery up and new fuel to see just how beat up she was, yet i was pleasntly suprised when she cranked up pretty with the help of some choke. However, upon closer inspection I found a number of issues with the motor.

1) lower unit is busted, cant connect a prop to it.
2) wiring is more or less gone and needs replacing before any real usage
3) gas lines rotting and leaking pretty bad (internal lines, not bulb)

I've got a manual so I've got a little bit of instruction on how to do everything. However, before diving in, I was wondering just how much worth my time it would be. Should I take the time to fix it or sell it and get a motor requiring less work? How much could I expect for a motor in this condition? Any comment is greatly appreciated. Thank you!

 

[mthieme]

Re: '73 Merc 500 50 hp

The lower unit is a show stopper. That with an internal wiring harness, all the rubber parts, you could easily wrap $500 into it w/o anyone else touching it.

 

[Laddies]

Re: '73 Merc 500 50 hp

First you say it's your granddads boat and engine that to me would make a labor of love and damn the price but you seen concerned about price. First if it's a Thompson Tomboy it was a rare boat when new so that helps it's value today, if your repairing it to sell you will be better or to advertise it and try to sell it to some one that wants a great old boat and not cobble it up and try to make a BUCK. As far as a lower unit there are 2 on Ebay right now with a buy it now of $500, a wire harness from Mercury is $84 and CDI $150 both prices are list. To replace the rubber lines it will take 9 fittings at about $3.50 each and $10 for line, $.90 each for clamps. these are list prices and you must do the work. If it don't run there will be further costs. Your call, your expence, remember it once was grandfathers pride.

 

[JReynolds11090]

Re: '73 Merc 500 50 hp

Thanks for the replies

I'm definitely keeping the boat, it was more about the motor. It sounds like it wil be worth the time/cost to to fix her up myself. thanks

 

[Moody Blue]

Re: '73 Merc 500 50 hp

Tough question to answer. I guess you really need to weigh the cost of repair vs the cost of a new ($$$$) or newer used motor (????).

I would not consider keeping it if you were not comfortable with a wrench in hand or if you were not willing to spend quite a few hours on it.

IF you are willing to put in the time, I think it would be worth it. Even if you were to completely rebuild the powerhead and replace the LU, you would only be into it for about $1200-$1500 and you would essentially have a new motor. Buying a used motor is always a risk, as you inherit someone elses headaches.