Water pump for 73 Mercury Thunderbolt

[Mercclunker]

Ok guys,

I am swapping lower units, and have been told I should change the water pump when im doing this. Where is the cheapest place to buy this? If someone could post a link to where i could buy one with quick shipping it would be helpful, because i havent even started this yet.



I have been told it is easy to swap lowers... (I was told its 4 bolts and it will pull out. and i can stick the other foot back in and bolt it up. Sounds too good to be true.) Is this true?

any step by step instructions would be great.

 

[Chris1956]

Re: Water pump for 73 Mercury Thunderbolt

Waterpump kits are available at many marine stores and of course merc dealers, as well as by web order.

You might post the HP of the motor you are working on. Inline 4 and 6 cylinder motors have 1 nut in the very front, two nuts slightly behind that, two nuts under the antiventilation plate and a hidden bolt under the zinc anode. Remove all these and the gearcase should be abe to be wiggled off.

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

Thank you for the input.

It is a 50 HP thunderbolt

HA been one of those days.

 

[Jacket4life]

Re: Water pump for 73 Mercury Thunderbolt

If you don't mind me asking, why are you swapping lower units? How much was the replacement? And what is your plan for your old one?

I have the exact motor you have (same yr. and everything!)

chris is correct, it's pretty straight-forward and that's pretty much the process.. Couple things I would add. Take ALL the nuts off EXCEPT the FRONT two. Just loosen them to the top of the studs, then wiggle the unit down to "get it started down".Then remove the nuts and pull the unit off. The reason is, sometimes that lower is "seized" on, and if you have to use some force, you don't want the unit to turns loose while you're pulling suddenly and hurt you or damage the lower. Second, when you are rplacing it, make sure you line up the water pump outlet with the tube and just push up a wiggle until the lower snugs up. You may have to remove a turn the driveshaft slighty a few times to get the splines lined b4 it will go on. DO NOT beat on it to get it on, you WILL break it. It may take a few tries. The first time, mine went straight on. The second time took bout 20 minutes of wrangling. The unit doesn't seem that heavy until you've been wrestling it a while! Be patient!

Oh, and GREASE the top of the driveshaft and the shift shaft. DO NOT turn the shift shaft!!!!!!!!!!!!!!!!!!! (If you want to know why, read my thread titled forward/reverse backward!!!) Just grease the tops of both with waterproof marine grease!

Best of luck, and my advice: Get a manual ASAP! It will make your life MUCH easier!

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

Jacket,

I was hauling across the river, and my motor just reved up, and the prop wouldnt spin. I thought the bushing on my prop was bad, but ended up I took the motor to my mechanic, and he said your lower is bad, and not worth fixing. I dont do well with that, so I got on Craigslist and picked up 2 spare motors in the same age range with good lowers, with various probs. I only paid 200 for the spare motors total. As for my lower I swapping out. Im guessing i would toss it, considering i have 2 more. I figured i would pick up the spares while i was at it because parts are hard to find and expensive. Thanks for the input.

 

[Jacket4life]

Re: Water pump for 73 Mercury Thunderbolt

Jacket,

I was hauling across the river, and my motor just reved up, and the prop wouldnt spin. I thought the bushing on my prop was bad, but ended up I took the motor to my mechanic, and he said your lower is bad, and not worth fixing. I dont do well with that, so I got on Craigslist and picked up 2 spare motors in the same age range with good lowers, with various probs. I only paid 200 for the spare motors total. As for my lower I swapping out. Im guessing i would toss it, considering i have 2 more. I figured i would pick up the spares while i was at it because parts are hard to find and expensive. Thanks for the input.

What area of the world are you in?? I'd like to have that lower as a spare/practice leg. I've never disassembled one. If you're close I can come get it, if far, I'd pay for shipping if it wasn't ourageous. Which it prolly would be...

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

I am in Hartselle AL....

That is a haul to TX, but once i disassemble, i would be glad to package it up in a box for you... and you can handle shipping. I will get back with you once i have changed out.

 

[Jacket4life]

Re: Water pump for 73 Mercury Thunderbolt

HEY!!!!!

My oldest daughter is going to be starting college in Troy next year! She is playing soccer and we have to go out there to a camp in June. How far away is that?? I'd be glad to take a detour to pick it up if you don't care?

 

[Jacket4life]

Re: Water pump for 73 Mercury Thunderbolt

Wow. Looked it up, it's 3.5 hrs. But there are a few lakes in between! Want to meet and go fishin?!?!

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

We will have to stay in touch...

I just had a baby boy last monday and he was 2 months early. He is still in NICU. If he is out and home and stable, I will seriously consider it man. Otherwise, i will have to stay here and look after the young one.

 

[Jacket4life]

Re: Water pump for 73 Mercury Thunderbolt

Man I hear you. Congrats! I'll be praying for you. If you don't mind PM'ing your (and your son's) name, we'll pray by name.

We have to be there for a weekend in June for orientation and another in July for a camp. She goes in late July to stay, but I will already be in two-a-days (I really am a coach!)

I will keep in touch by PM if it's o.k. with you. It would be great to meet someone on here, I've gotten TONS of help here in a VERY short time! A'int the internets wonderful?!?!!? So glad Al Gore invented them! LOL!!!

Oh, and I don't think any of us told you, but you can order that impeller from here on iboats, don't know if they are the cheapest, but it would be a good thing to order from them, they run all this for free! I'm gonna get my carb and fuel pump kits from here!

Best of luck, and hope things work out for the best with your son, our youngest daughter was a month early, she spent 8 days in the hospital (just about killed my wife!) But has had NO complications since. Wish you the best!

Scott

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

Am i suppose to replace the impeller, or the whole water pump when you swap lower units?

Thanks

 

[Chris1956]

Re: Water pump for 73 Mercury Thunderbolt

Replace as a minimum, the impeller, the wearplate and all gaskets. Inspect the waterpump cover for scratches and wear. If you find it, replace the waterpump cover.

 

[Mercclunker]

Re: Water pump for 73 Mercury Thunderbolt

Parts on on the way....

Thank you very much for the information!

 

[Moody Blue]

Re: Water pump for 73 Mercury Thunderbolt

Oh, and GREASE the top of the driveshaft and the shift shaft.

Just to clarify, DO NOT apply grease to the END of the shafts. Only grease the splines. Grease applied to the ends of the shafts could prevent them from properly engaging when reassembling. The manuals warn about this.