55hp Rectifier 3 and 4 wire confusion?

[ronsealdeath]

Hello, I have a 55hp Evinrude circa 1976 (flatter saucer shape flywheel). I think its been subject to parts exchange from a later 55 (dome shaped flywheel) as it has fixed jet carbs?

I am totally confused by the rectifier wiring though having worked out that my rectifier isn't working (not charging battery and tacho doesnt work). I havent done the ohm test as I can't get my head around it so this could be a wiring issue?
Anyway, my stator has a sleaved wire coming from it with 2 yellow wires and one brown wire. The brown wire goes to the power pack and the other two wires to two wires on the rectifier. (There is another sleaved wire from the stator with two cables going into the other side of the power pack). There is also a red wire from the starter solenoid to the rectifier. This leaves one more yellow wire on the rectifier which is only connected to the grey tacho feed to the big red plug to the control box. So I have a 4 wire rectifier. Now far be it from me to make an assumption but shouldnt my engine have a 3 wire rectifier and not this 4 wire one that is currently fitted? It appears that the original rectifier may have blown and previous owner used his later 55hp to replace it for a 4 wire one?

I happened to have a 3 wire rectifier from an old 72 Johnson 50hp in the garage. Can I just wire this up then? From the parts manual my motor should have the same rectifier as the spare 50 I have. Or am I losing the plot with all these wires. :facepalm: Some are so faded I can't really tell what colour they are but am best guessing! I guess the 4 wire one installed may be working then but is just wired to the wrong motor.

Sorry if this is confusing. Any help would be great.
Cheers
Al

 

[ronsealdeath]

Re: 55hp Rectifier 3 and 4 wire confusion?

Hello again,

Can I ask a simpler question then; how many poles does the stator on my 1976 Evinrude 55 have? Some places I've seen say 10 and some say 12?

I also hooked up an old Yamaha tach with 2 wires which was giving me a reading of 4500 RPM at tickover! Is this because its set to the wrong number of poles? There is no option on the tach that I can see to change the poles setting. Is it useless to me?

Thanks
Al

 

[F_R]

Re: 55hp Rectifier 3 and 4 wire confusion?

So you have only two yellow wires coming from the stator? It takes a 3 wire "bridge" rectifier, two yellow and a red one. The tach connects to one of the yellow wires, along with the stator wire and rectifier wire. Some may have a black ground also, but is the same thing. The 3 phase rectifier (3 yellow) is different. The stator with two yellow wires is 12 pole (6 pulse).

 

[ronsealdeath]

Re: 55hp Rectifier 3 and 4 wire confusion?

Many thanks for confirming that. I'm going to ditch the old tach and get a new one. We need a new prop and I am reluctant to buy one without checking out RPM at WOT etc...

I have now wired up the 3 wire rectifier and will check if the battery is charging next.

Thanks again
Al