McColloch 7.5 help!

rcman098

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Mar 19, 2013
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Hello everyone,

Im new the outboard restoration world and I just bought my first project. Its a 1962 McColloch 7.5 low profile outboard. The previous owner (retired cop and boat enthusiest) said he replaced the fuel diaphram, plugs and impeller however, he could only get it running on starting fluid. I went through the motor and everything looks fine(exept the carb wich is soaking in cleaner now).Man this is a pain to work on!!!:eek:The face plate is there but cracked, and the cowling is there but also cracked. Im looking for some general info about the motor, like the Bail-O-matic Im reading about and oils, ratios ect...

Thanks!
 

F_R

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Jul 7, 2006
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28,195
Re: McColloch 7.5 help!

Heh, you sure picked a dandy for a first project didn't you? You already found some of the main drawbacks. But you didn't come here for negative comments, so the bailer is a second water pump stacked on top of the cooling pump. I'm not sure about the oil, but back in that era Scott/McCulloch had their own oil for 100:1 mix. Doesn't matter, you won't find that stuff any more, so run 50:1 with any TC-W3 certified oil.
 

rcman098

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Mar 19, 2013
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Re: McColloch 7.5 help!

It's defiantly a pain to work on since you need to remove the power head to do anything! Can you explain what this bailor does? And dose it have to do with the hose attachment on the side?
 

Circlemooner

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Mar 21, 2013
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Re: McColloch 7.5 help!

Heh, you sure picked a dandy for a first project didn't you? You already found some of the main drawbacks. But you didn't come here for negative comments, so the bailer is a second water pump stacked on top of the cooling pump. I'm not sure about the oil, but back in that era Scott/McCulloch had their own oil for 100:1 mix. Doesn't matter, you won't find that stuff any more, so run 50:1 with any TC-W3 certified oil.

I'm working on a 1961 Elgin 7.5 right now..... "dandy" is a very polite way of putting it. But it was my dad's motor before he passed and getting it going again is a labor of love. Compression feels good and like yours it will run on starter fluid. Have mine down to the carb and cleaning now. The diaphram seems to be intact and flexible, but I'd feel more comfortable putting in a new one, considering the effort it takes to get the powerhead off. Should I replace the impellers since I'm sure they are original and it's stripped down this far already? Any ideas on where to find a carb kit for it? Marvel Schebler SUM 13
 

Howard Sterndrive

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Nov 5, 2008
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4,603
Re: McColloch 7.5 help!

I used to get all the parts at Laing's Outboards... not sure if he still has parts.

You'll eventually get to the point where you can pop off the recoil, and flywheel and have the powerhead out in about 15 minutes. Long needlenose pliers will help you clip and unclip the fuel hose clamps -probably the most tedious part of it.

Like Circlemooner, I inherited my dad's and it has maybe 5 hours on it since new, but never did run reliably. I will get around to the proper resto/cleanup one of these days. I have a bunch of stuff squirreled away off eBay including a NOS hood! :)

The diaphragm in the fuel pump needs in VERY good condition for these things to run. Any loose pockets in the material and it won't pump.
 

Circlemooner

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Mar 21, 2013
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Re: McColloch 7.5 help!

NOS hood????? Wow! If you ever need a place to store it, I have room in my barn :lol: I'm waiting for a reply from Laings on the carb parts.
 

Circlemooner

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Mar 21, 2013
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Re: McColloch 7.5 help!

I used to get all the parts at Laing's Outboards... not sure if he still has parts.

You'll eventually get to the point where you can pop off the recoil, and flywheel and have the powerhead out in about 15 minutes. Long needlenose pliers will help you clip and unclip the fuel hose clamps -probably the most tedious part of it.

Like Circlemooner, I inherited my dad's and it has maybe 5 hours on it since new, but never did run reliably. I will get around to the proper resto/cleanup one of these days. I have a bunch of stuff squirreled away off eBay including a NOS hood! :)

The diaphragm in the fuel pump needs in VERY good condition for these things to run. Any loose pockets in the material and it won't pump.

Thanks for the info, Laing's didn't have the carb kit. Found one at Discount Marine Parts in Michigan. They also had a new impeller, since I'm this far with it.... might as well. :cool:
 

steverobbins

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Jul 6, 2013
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Re: McColloch 7.5 help!

It's defiantly a pain to work on since you need to remove the power head to do anything! Can you explain what this bailor does? And dose it have to do with the hose attachment on the side?

How do you get this powerhead off?. I have all of the screws out but I am so afraid to crack this lower case. Should it just slide out after you get all the screws out or do you have to remove the lower unit?
 
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