Mark20

[speedy102]

I just picked up a Mercury Mark 20 in hopes of restoring it,seems to be complete,nothing missing or broke..However I am finding out very quickly that these parts for this engine are far and few!! i understand that there are no points available anywhere for it,but condenser and coils are....i found one guy on the internet who rebuilds water impellers,actually molds new rubber to the hub....Anybody know where I can find the impeller????? Also I can not get the prop /nut off!!! is it left or right hand threads???? It is the cone shaped nut with the hole in it for inserting a round piece of stock to tighten or loosen...I have soaked with kroil penetrating oil numerous times and it still will not budge!haven't tried a little heat on yet though,but I am unsure if it is right or left hand threads??? I assumed it was left hand threads...Any suggestions/help would be highly appreciated......thanks!!

[ZUL8TR]

Mark 20 info

Look here lots of members know all that you need.

Become a member and ask away.

http://johnsoldmercurysite.com/phpBB...90f136610553f8

[Charlie Pater]

Parts and advice can be had from Frank Erion. 269 720 1337

[3autility]

mk 20

oldmercs.com also has parts.

[speedy102]

I already checked with oldmerc.com and they have practially nothing .....lots of parts listed there but out beside it is: Not Available or No longer available... but thanks for the lead....

[Guest]

Mark 20

We have all the gaskets in stock for the Mark 20 at Aeroliner-Boats.com. We also have a lot of used parts for the engine. I have a number of used magnetos with good points also if you really need points. Most times they easily clean up. Parts are available but you have to look. I currently have a Mark 15,20 and 25 in my collection. If you need to change the water pump impeller it is best to find the Mercury special tool.

Alan

[bh/]

The stock M20 came with a Bendex -Scintilla mag, not Phelon,
as on the 20H. Points are NLA, and the mag is troublesome to begin with. They can be adapted to a Phelon, but not worth messing with, IMHO
But yes, ask away on 'Johns Ol'Mercs',

[dndsam]

You can get many parts at marineengine.com or vintageoutboard.com , unfortunately the points will be the trick. Here is a quick link to the MK 20 selection at marineengine.com

http://www.marineengine.com/parts/me...15-kh7-wg7/all

Doug S.

[3autility]

mark 20

I respectively disagree about the Scintilla mags, I have not had a bad experience with them in any of the motors that I have: Mark 20, Mark 15, KG7, (both H and Q and service motors). If you have good coils, condensers and the points are clean, they work fine. Any other thoughts form members???

[Mike45]

You can get a complete set at Outboardparadise.com, He may or may not have the coils (scintilla) he also has points, but I know oldmercs.com has them (coils). They are not cheap, Also a lot of times your condensor will be the culprit if you see it fails to have spark. If you have the patiance just start switching these parts back and forth to see which part is not giving you spark. As far as the prop nut it is right handed but I BELIEVE but do not quote me it has a washer that you must bend the tabs back out so it can be removed (just as the recoil has) It has been a while since I actually worked on a fishing lower unit. I normally just take the lower unit off and put a "quicky" on.

I also believe the scintilla mags are a much better system than the phelon once you get them "tuned in right". I have never had one fail on me yet. I would also set you point gap between .015 - .018 depending on the wear/use that this motor has on it. Go for about .016 on both as a starting point.

I'll go and look at one of my old lower units and get back to you just to be sure on the "cone" removal.

[16JBilly]

napa autoparts said 2 months ago they could get 20h points out of somewhere in mass

[jeff55v]

These motors were old when I raced them 30 years ago.
I remember even back then, having no luck finding ignition parts for the scintilla ignition. I found it an easy fix to swap out the entire ignition and flywheel for a Phelon with all new components. Back then, I could get all Phelon parts easily.
Another oddity about the Mark 20 was the pressurized fuel tank system. If you have a good fuel tank, hoses, and connector for this system, it'll probably work ok. But in my instance, I usually converted them to a standard fuel pump and tank system.
I'll look in my service book about your prop nut. I don't think it's a left handed thread. But I'm not sure enough to have you risk breaking off your propshaft.

[Mike45]

update

Prop nut is right handed but you must bend the tabs back and use something that fits pretty good in the hole of the cone.

[jeff55v]

My book says the Sierra number for the impeller is 18-3008.
I don't know if it's still available.

[Guest]

Mark 20 magneto

Going through my parts supply today at the shop I found about 12 Bendix mags with points and coils including the cover. I will offer a complete mag for $35.00 plus shipping. If anyone needs a photo please let me know.

Alan