mercury 7 1/2 hp

[guzzi-john]

I’m looking to get one of these in a swap but am not sure of reliability. It is a 1971 and by web surfing I seem to find that year had an oddball ignition that wasn’t used again. I want to know if that is true and whether later/other systems could be put in it. I looked at stators online and they seem very pricey. That said I observed that new ones seemed to include lighting/charging coils hence high bucks. Others on ebay were just a plate w 2 coils. I am a retired lifelong mechanic/motorcyclist/motor head with some OB experience so swapping and modding are nothing new to me. I’d like to fix the motor up for my son and grandchildren. Thank you, John Pierson – Champlin, Mn

[jeff-register]

John,
I’m not sure but maybe you can fit an early mag on it, coils are enough. Dave help us.

[dockbuster1]

Green coils replaced the brown , new point insulators and make shure the breaker stop switch is clean and has a good ground other than those items I find even the old stators work well good luck

[guzzi-john]

Thanks guys. I read about the insulators and switch issue. Why were coils changed(what is different in them) and is that what made 71s odd? So they are reliable? I’m used to the issues w 70s & 80s motorcycle ignitions and black boxes.

[jeff-register]

Same principal, different shape,

[20mercman]

A lot of folks had issues with the "Maker Point" ignition systems, and also the "Phased Maker" systems used in 1972 & 1973 (1973 for the 9.8hp and smaller motors only as the 200 went to breakerless in 73) But as has been pointed out, the path to ground on the primary ignition circuit is via the stop switch. These motors used a very high voltage in the primary circuit vs. the previous magneto systems. The were basically a CDI with points instead of a trigger. In any event, the insulators for the points are prone to carbon tracking, and also using the kill switch, especially at RPM’s above idle generate high stray voltage that is looking for a path to ground. I have two 1972 200’s with the "Phase Maker" system, and I really like these motors. They are great starting, and very good performers, idle all day and smooth as can be. It is true that stators are expensive, especially for the 1970 & 71 years, but I would not be afraid of this motor at all. You don’t state if this is in running condition, so that of course makes a big difference. If not, then plan to invest some money into it. These can be converted to the old style Phelon magneto, but you would need everything to go along with it. The crankshaft is the same, but you would need the cam, magneto, flywheel, and stop switch. Perhaps some throttle linkage changes also. (Not sure on that.)

Steve

[guzzi-john]

The owner isn’t a motorhead but he says great spark but can’t get started. That seems to indicate no fuel/plugged carb etc. I seem to recall some early CDIs could be killed by cranking wo grounded plugs. I would hope the CDI would be good if any spark is produced. I see stators on ebay that are just a plate w 2 coils vs the fancy alternator type w 4 extra coils-does the 2 coil piece have the CDI in it?

[20mercman]

This is what the stator of the 1970 & 71 motors look like.
http://www.marineengine.com/parts/mercu … ition-coil

Steve

[guzzi-john]

OK, then the round unit w the 4 coils on it is not an alternator but rather hi & lo speed coils I read about right? I’ve rewound bike stators by hand and grafted different regulator units into them but this involves the CDI which I have no clue on how to deal with if bad(besides the big$$ route). I saw the Utube video of replacing insulators and such so not worried about that. The ones on ebay w just 2 coils directly opposite must be earlier magneto units. I don’t understand how the 4 coils in a row work so I’ll read some more. Your praise of the 7.5 makes me think that the deal is good.

[outbdnut2]

Yeah – I’ve got a 7-1/2 with the maker points and a dead stator too. I’m thinkin’ it will be a parts motor, but being a retired electronic guy, I have entertained the thought of building a replacement stator – just as an interesting challenge to keep my brain somewhat sharp…..but I’ll probably never get around to it – too many other things more fun to do, and I’m about 40 or 50 other motors, and a couple of boats behind to restore (nine more motors followed me home a couple weeks ago). I’m curious: Does anyone have a circuit for one of these stators?
Dave

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