Mercury Mark 20 Rebuild

[jpatti75]

quote bwiggins1985:

quote jpatti75:

I converted my Mark 20 to a fuel pump, too. You need the pump off a Mark 25 or one of the motors you listed, along with the backer plate in order to mount it to the powerhead. As for mounting the bayonet style fuel connection, I actually replaced the port side cowling from the Mark 20 with one from a Mark 25, so I didn’t have to deal with coming up with a solution to mounting the fuel fitting on the original port side cowl. All the fun of the Mark 20 with the conveniences of a Mark 25. 😀

Another option is buying a cool single line fuel fitting that some crafty guy concocted to work with the original Mark 20 fitting. I’ve seen them on eBay for sale, but can’t find one currently.

JP

Got any pictures??? 😀

Here is a video of my Mark 20 running, and you can see it has the Mark 25 port side cowling and I am using a single line, bayonet-style fuel connector. I’ll see if I can find a picture of that connector someone came up with to work with the original Mark 20 fuel connection.

https://www.dropbox.com/s/7zr34htmokdaw … M.mov?dl=0

[jpatti75]

Here is an old posting on iBoats about the custom fuel connector I having been talking about. It will work with the original style female fitting on the Mark 20. I used to see them on eBay, but they aren’t available at this time. Hopefully someone else can point you in the right direction, if you want to pursue one.

http://forums.iboats.com/forum/engine-r … -fuel-pump

[johng]

If you can’t save the points you have, the early KF-5 Merc’s 1949′ Easier to find. KF-7 1949′ & KG-7 used the same ignition parts. Use a small soldering iron or a file to remove solder. Heat can damage coil. Hope this helps.

[bwiggins1985]

quote Chinewalker:

You have the newer replacement coils in there – nice score! They’re pricey if you need to replace them.

I concur – focus on the condensers (new can be found) and the points (not aware of new replacements available anywhere). Disassemble and CLEAN the points. Contact surfaces should be shiny and squared up to each other.

I found a gentlemen from the form that has lots of the pieces and parts I am needing! Super excited for all the help and support! I will check the points and everything tomorrow and get a list of new parts and pieces to order!

[bwiggins1985]

quote jpatti75:

quote bwiggins1985:

quote jpatti75:

I converted my Mark 20 to a fuel pump, too. You need the pump off a Mark 25 or one of the motors you listed, along with the backer plate in order to mount it to the powerhead. As for mounting the bayonet style fuel connection, I actually replaced the port side cowling from the Mark 20 with one from a Mark 25, so I didn’t have to deal with coming up with a solution to mounting the fuel fitting on the original port side cowl. All the fun of the Mark 20 with the conveniences of a Mark 25. 😀

Another option is buying a cool single line fuel fitting that some crafty guy concocted to work with the original Mark 20 fitting. I’ve seen them on eBay for sale, but can’t find one currently.

JP

Got any pictures??? 😀

Here is a video of my Mark 20 running, and you can see it has the Mark 25 port side cowling and I am using a single line, bayonet-style fuel connector. I’ll see if I can find a picture of that connector someone came up with to work with the original Mark 20 fuel connection.

https://www.dropbox.com/s/7zr34htmokdaw … M.mov?dl=0

So the factory Mark 25 cowls come with the single line connector. All you need is the male hose end?

[RICHARD A. WHITE]

So how many of US are hoarding points for these?

I for one have 4 sets…. and I know others have them as well…
One set still in the box….3 sets on working motors..
And I know for a fact I will probably not ever need all I have.

I know how stingy people get with these, so I will do this…If you send me your points, I will put them on a working mag to see if I can salvage them, only cost to you if it works will be shipping both ways, if they do not work I will send you back a NOS set, now they will have some cost as they are what they are.

If this is agreeable we can talk details of the NOS set, I will not rip you off on the new set either.
My guess is yours are just really needing a good cleaning.

Anyway PM me and we can get this process rolling.

Regards

Richard

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[green-thumbs]

Mercurys are different
Good Luck
Louis

[dave-bernard]

Mark20 pump is on the drive shaft and is right hand thread.

[bwiggins1985]

quote betty ann bernardd:

Mark20 pump is on the drive shaft and is right hand thread.

I have tried to find some blow ups of that. I am going to try to get a manual this weekend…I have bought a bunch of goodies already since this last weekend and the wife is a little frustrated 😀 😆

Anyone have any pictures of this install?

[jpatti75]

quote bwiggins1985:

So the factory Mark 25 cowls come with the single line connector. All you need is the male hose end?

Yes, Mark 25s all came from the factory with a fuel pump, and consequently the single line fuel connector (which is actually the male end). So if you find a Mark 25 port cowl with the fuel connector intact, then you just need the tank side, female fitting — which is still available new.

Here’s a set of Mark 25 cowlings on eBay, and you can see the male fitting still intact:
https://www.ebay.com/itm/262710639910

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