Mercury 22ci Powerhead on 20h Conversion Tower

[deeougee]

That’s pretty slick with the OMC coils. I thought Mike 41P also had a complete cdi conversion kit for the Mark powerheads. I’m still going to investigate mounting a newer cdi 22ci powerhead though because of parts availability. Thanks for posting though, that will help out a lot of people. The Merc coils are really pricey now and are really old so this is really a better option as a direct replacement.

[fastjohn]

Not sure this will work, but this is the way to change phelon coils to OMC.
https://www.youtube.com/watch?v=OxPHe8EPe1Q&t=80s

[larry herman]

Has anyone ever mounted a late 70’s early 80’s mercury 22ci powerhead on a conversion tower? I’ve seen them mounted on a regular 20h tower, wondering if anyone has put one on the conversion tower. Reason for this is I have a tower here that no one seems to want and I’m not chasing coils for the old mark powerheads. So time to come up with a game plan for this tower. The 22ci powerheads are dirt cheap and I can get parts.

You, can still get the merc coils 398-173 & 18-5178 but not cheap, although at a race someone used OMC coils, new and very cheap with slight modification to the mag plate with the plug wires coming into the back side of the coils. Maybee someone will see this post and confirm this along with the coil numbers. regards, Larry

[deeougee]

The merc 250 25hp motor still uses phalon coils and I want to stay away from those. The coils are old and expensive unless you get them rewound. At least with a new rewind you are getting reliable parts. With the newer 22ci powerheads you get into the cdi ignition, the motors are a dime a dozen. The early model 73-76 25ss powerhead is probably the most desirable since it had cdi and the light flywheel and was reported to be more reliable than the later 25ss engines. We’ve had a couple of Merc 20hp fishing engines from the 70’s early 80’s and never had a lick of problems with them.

If you proceed with the project, I would get an old Merc 250 25 HP powerhead. They are hard to find but really perform well. Ran one for years on a regular quicksilver tower with great results running the little feature in EORC club races on Long Island. Also had a 25SS on a conversion tower which was hard to make work but doable.

[deeougee]

If I go forward with this project I’ll make it work. First thing, get the powerhead. I have full machining capability in my shop now so no need to use others equipment or farm it out. Back when I worked at Ford Windsor Casting Plant I could make a pattern of something and make the part if I needed something modified. I did it with 2.3 liter intakes. There were people working on a lot of things back in the day. Saw someone who runs at Bonneville make a v6 engine from scratch based on 351 Cleveland geometry.

[bill hoctor]

Like the question

[DeanFHobart]

What about the filler block and elbow?

[deeougee]

Yes Pete. Was going to take your advice and off the tower and not go down this rabbit hole. I can get complete 20 merc powerheads RTR for a couple of hundred. I’m not going to chase coils for the old powerheads but I do have a contact for getting those rewound. Then i still have to get a foot and would run a deep skeg unit. Would really rather move on from this project.

[ZUL8TR]

At 1000 CDN that has to be without the gear case. Are you looking for a complete 22 ci power head compete with ignition, carb, recoil, ready to run?

[deeougee]

Well not exactly giving it away. Ask is 1000 CDN which is what? About 730 US at recent exchange rates. Pretty reasonable ask considering condition. Swivel bushings are tight, clamps are good, really clean unit, hasn’t been used much. If it had a nice ID tag I’d be asking for more. These days it seems like people are more interested in posting up race pictures and schedules on social media than having any type of real discussion. No big deal. If I end up getting a 22 ci powerhead I’ll make it work, have full machining capability here at my shop now.

[Entler]

You say you have a conversion tower that nobody wants?! Feel free to put me on the “wants” list!

[deeougee]

Has anyone ever mounted a late 70’s early 80’s mercury 22ci powerhead on a conversion tower? I’ve seen them mounted on a regular 20h tower, wondering if anyone has put one on the conversion tower. Reason for this is I have a tower here that no one seems to want and I’m not chasing coils for the old mark powerheads. So time to come up with a game plan for this tower. The 22ci powerheads are dirt cheap and I can get parts.