Mercury 50 exhaust stack plugged?

[checkoutmyjunk]

Hello all, New here so I apologize if I am doing somthing wrong

I recently acquired a 50 that was my dads, he bought it new back in the early 80s. It was dead reliable back in the day, we had a cabin on an island in the river so we used it every weekend. This motor sat on the back of our john boat uncovered and year after year and it worked flawlessly despite not mantaing it properly. When spring would come we would pump the ball, pull the choke out and give the cord a few tugs and this motor would fire right up. So when I recived it and saw the wireing to the stator was crumbeling I figured I would run it to the shop have them replace it and I would be good to go. Well once the stator was replaced I got a call saying the tiller cable was frozen and once that was fixed I got another call telling me that the carbs needed rebuilt. Once that was done I got a bill for just shy of 1000 bucks. WAY more then I wanted to invest.

I picked the boat up today and find that the bill had a note for me. "Engine moves around a lot - possible bad motor mount & smoke comes up and out under bottom pan ( chould have plug up in exhaust stack) - does have fuel sheen in water when running"

I called the shop back and they told me that I should remove the power head and check the stack. I have read a bit about removing the powerhead and it seems like it will be a pain in the ***, so before I do that I thought I would ask for some advise. What would you all do if you were in my shoes? What is this motor even worth? I am already 1k into this and feeling like i might cut my losses. I am handy with mechanical work and have complete motor swaps on cars and motorcyles.

Bringing this back from the dead. Finally, I started this little project. I think that I might have gone at this wrong so I am hoping you forum gurus can lend me your wisdom. I separated the power head from the lower half (lower unit?) and now I would like to replace the motor mounts and exhaust gaskets but I can't to sort out what order I should have dismantled this bugger. As you can see from the pics I am not sure how to separate the exhaust stack from the power-head, what steps did I skip? Thanks in advance for any help you can provide!

once I get this buttoned up I would like to put a tutorial together to share with the forum so that others don't get stuck like I am.

 

[huntin dawg]

Re: Mercury 50 exhaust stack plugged?

My personal opinion... You are already about $900 more into it than you should be. That grand you spent could have bought you a much newer motor. Unless you have a sentimental attachment to the motor I'd say cut your losses, use it as is and get what you can out of it before it dies for good. Then invest in a newer motor.

Just my 2 cents.

Good luck,
HD

 

[Chris1956]

Re: Mercury 50 exhaust stack plugged?

The upper motor mounts are sandwiched between the midsection and the exhaust extension. This is likely the place where the exhaust is leaking. I doubt the exhaust outlet is plugged. If it was the motor wouldn't run at all.

Remove wrap cowling and the 4 phillips screws that hold the cowl (that says 50HP) on the midsection. That will expose the powerhead mounting bolts, and the joint between the midsection. exhaust extension and powerhead.

Rock the powerhead away and to the boat, and see how much play there is. If there is a lot the motor mounts or bolts are shot. If you can get new motor mounts and a couple of gaskets, and are prepared to remove the gearcase and powerhead, it is a fairly simple repair. Certainly a service manual is a good idea.

 

[Dave1027]

Re: Mercury 50 exhaust stack plugged?

And to add, I think the shop you are dealing with is ripping you off. It sounds like they don't know what they are doing. They are only succeeding at one thing ... taking your money. You have spent a grand and you still don't have a running boat. Now they are giving you a **** and bull story about how you need to pull the powerhead?

 

[SeaKaye12]

Re: Mercury 50 exhaust stack plugged?

Is that a tiller-handled 50 HP? When you talk about "giving the cord a few tugs"and tiller cables.....you've got me wondering....

I can't help but think that the shop has done you no favors....It would have been nice if they would have spent a little time looking over the engine's overall condition and making recommendations as to the feasibility of any repair before setting off to charging you a lot of money.

That's why so many of us are here....our old motors aren't worth what a shop needs to charge to work on them....still it's a shame just to part them out or (worse) send them to the landfill....

Chuck

 

[checkoutmyjunk]

Re: Mercury 50 exhaust stack plugged?

THANKS A TON!

I am glad there are nice folks out there that are willing to take their time and offer advice to folks like me. I have decided to pull the power head, check the stack and replace the gasket and motor mounts. I am deciding if I am going to try to voice my findings to the owner shop manager of the shop.

I called the shop back after looking the bill over and asked them for advice, I explained to them that I thought that this motor was worth about $2k and that I am getting close to spending more then it's worth. The service guy told me it was worth $1200 and that it would be another $500 to remove the power head and clear the stack. I told him that I have been doing engine swaps on cars, 2stroke dirt bikes and motorcycles for years and if he thought I would be able to do this repair my self. He gave me a over whelming NO!, he said that nothing I learned from cars and bikes will translate to working on an outboard.

Would images of the tear down be useful to the community?

 

[checkoutmyjunk]

Re: Mercury 50 exhaust stack plugged?

Yes this is a till model, no starter no alternator nothing just a tiller, pull cord, shifter, choke, and a stop button.


Would you folks call and voice your complaint to the shop owner?

 

[checkoutmyjunk]

Re: Mercury 50 exhaust stack plugged?

Bringing this back from the dead. Finally, I started this little project. I think that I might have gone at this wrong so I am hoping you forum gurus can lend me your wisdom. I separated the power head from the lower half (lower unit?) and now I would like to replace the motor mounts and exhaust gaskets but I can't to sort out what order I should have dismantled this bugger. As you can see from the pics I am not sure how to separate the exhaust stack from the power-head, what steps did I skip? Thanks in advance for any help you can provide!

once I get this buttoned up I would like to put a tutorial together to share with the forum so that others don't get stuck like I am.

 

[checkoutmyjunk]

Re: Mercury 50 exhaust stack plugged?

Bumping this to page 1

 

[merc850]

Re: Mercury 50 exhaust stack plugged?

Here are 2 pages from the 1975 manual that should help. I can't tell from the photos but the diagram shows that the exhaust tube bolts onto a stub from the powerhead, I would just look up the tube and see if there is a blockage before tearing it apart.
Replace the Driveshaft to powerhead gasket and make sure that there is a rubber fitting in the lower unit that fits onto the end of the exhaust tube.
And for god's sake put some anti-corrosion grease on the shiftshaft and powerhead splines and any other bolts you wrench, even stainless!
Oh yeah and put in a new waterpump impeller.
I have seen a motor with a plugged up exhaust tube and it's caused by poor/over oiling, too much slow speed operation too high prop pitch. Mercury makes a cleaner called Power Tune and it will clean the cylinders etc.