Mercury Mark 10: several questions

[Mark10]

If this were a '67 VW Beetle, I could figure it out, but I'm new to outboards.<br />I'm replacing the fuel lines on a '57/'58 Mercury Mark 10 but can't find the brass fittings for the 1/4" hose. <br />I also can't find a female tank-side fuel adaptor that plugs into the male end on the motor. <br />So, is there a problem with replacing the old adaptor with a more contemporary 3/8" adaptor and then stepping down to say a 5/16" line to get into the fuel pump? How about also using 5/16" line between the pump and the carb?<br />I've also noticed that some folks recommend sticking with the originally recommended Lubriplate 105 in the lower unit, but others swear that hypoid 90 wt. works just as well. Which is right? Sorry if that's already been beaten to death.<br />The motor came with Champion J6C spark plugs though J7J was originally recommended. Are they interchangeable?<br />And one last question, does anyone have an opinion on this motor? Any peculiarities? I notice that Mercury only made it for two years.<br /><br />Thanks.<br /><br />Jack Rose

 

[Chinewalker]

Re: Mercury Mark 10: several questions

Hi Jack,<br /> Replacing the fuel lines with a different diameter won't affect much, as long as you're not going smaller than the 1/4" I.D. <br /> As for other motor issues with the Mark 10s - they're not easy to work on - particularly if you have lower unit problems. You either have to find the original tools or cobble something together to get it apart. Even something as (generally) simple as changing the water pump impeller becomes quite a project. I would highly recommend getting the 1965 and prior Merc manual from Grubb's (www.oldmercs.com) as it will answer many of your questions. <br /> The powerheads were generally quite good - dependable magneto and tried & true fuel system. It was basically a sleeved down version of the 22-cube motor, checking in at 18 cubes. Lots of cubes made for a generous 10hp.<br /><br />- Scott

 

[Mark10]

Re: Mercury Mark 10: several questions

Scott,<br /><br />That's what I was hoping. I've already gotten the manuals from Grubbs and have seen the problems with changing out the impeller. I'm hoping that a guy down the road who's into old Mercurys can help me there. <br /><br />Thanks for the info,<br /><br />Jack Rose

 

[Yepblaze]

Re: Mercury Mark 10: several questions

You might find a lot of info at John's Old Mercury forum <br />

<br /><br />You can just grind away the crimped area on the existing hose, and what's left is a couple of short hose end fittings, that if carefully used with clamps might get you by.

 

[Chinewalker]

Re: Mercury Mark 10: several questions

Hey Blaze,<br /> Sweet Cruiser KH7! I haven't run mine in awhile, but it absolutely launches my 12-foot DuraNautic. Here's a pic of me 20 years ago (and 100 lbs ago!) running the same boat with a KE7 Lightning...<br />

<br />- Scott

 

[Mark10]

Re: Mercury Mark 10: several questions

Hey, good idea on using the old fittings, that might just work. Thanks.<br /><br />Now I need to figure out a way to get the impeller out without doing any damage.<br /><br />Thanks again,<br /><br />Jack Rose