Reply With QuoteNext time your in the water put a volt meter between the two and see what you get.
I just finished doing the annual service on my 90HP Suzuki's, everything went well, BUT, one motor the zincs were very badly eaten, the other motor not so much, and just started kind of wondering why, the motor with the most eaten anodes is also the one the power for the radio, lights and other "stuff" is taken off, could this possibly have anything to do with it? Before anyone starts with funny questions, all accessories are wired correctly, it's a fibreglass boat, there is isolation battery switches, both motors are running fine, it just got me thinking though, why? Even the external anodes are much worse!
Next time your in the water put a volt meter between the two and see what you get.
Funny you should say that, I was going to do some testing and see if something comes up, it just seems strange that one is so much worse, I guess one way to look at it, they are doing their job! or at least one side is, I will take a photo of them to show how much difference there is.
The suspicion would be that there is no heavy negative between the battery banks or some other resistance in the negatives so as to allow them to not be at the same potential. I have seen similar issues with battery monitoring systems - had a 1.6 volt potential between the negatives of the banks (in this case a house bank) which was sufficient to create charging issues. With the shunts bypassed all was good.
The motors are on a cat, so two completely different battery setups, controls and everything else, the two motors have nothing in common but the water! The Port motors battery does supply power for all accessories, now that I have just replaced the anodes, I might swap the power source for the accessories and see if the starboard motor exhibits extra wear in a few months rather than the port one.
Might be worth a leakage test too. Low range ammeter in the effected motors negative line, disconnect the positive so there is no chance of the motor itself generating a reading and then start running accessories to see if there is any leakage back through the engine.
As a side note - not the first time I have heard of a Zuke's anodes being almost gone in 12 months. Talking to a well respected Suzuki dealer up here he made specific mention that annual inspection was pretty important too.
Do you have 3 sets of anodes on each motor Noel,.... internal, swivel bracket & leg?
If so are all 3 sets exhibiting the same increased deterioration levels compared to the 'good' motor?
Motors connected together by the steering and possibly the controllers?
Like to guess the hours involved, on a fibreglass trailer boat I'd expect the external anodes to last forever (read a very long time).
Im not electrically literate......but I do find these sort of things useful to follow through...cos I learn a lot from the wise....the only small offering I have is...is this the side of the boat that has the transponder on it?
Yep, internal anodes X 3 external near gearcase X 1 and a big one on the bracket, all eaten considerably more than the good motor. Possible common "connection" steering link, binnacle control? salt water when in use, everything else is isolated, seperate batteries with no possible way to connect both, fibreglass boat, I guess if there was only one motor, you wouldn't know or care if one was eating anodes, but having the two kind of gets you thinking.
The one that is good is the side the transducer is on, but not too sure if it is anything to do with it, just to add, I am pretty up to speed with electronics, having been a TV repair guy for years, and a computer support guy, including component level repairs for 20 years, so know my way around test equipment.Originally Posted by inveratta
OH, I forgot, motors are at just over 200 hours, first 100 hour service was similar, but really didn't consider anything wrong at that time, Suzuki have service kits, and for some reason, I kept the old boxes with the used parts in them, and labeled them port and starboard, I checked the old anodes yesterday, and that's how I know it was the same at the last service.
Does that mean 2 different power sources but now have a common negative and one of the power sources supplying power to accesories. I have no idea of the ramifications not being electrically literate but using basics of doing one thing at a time to eliminate problems how do you eliminate one or the other to check the theory, connect both motors to one battery as a start maybe and see if the problem still exists.
I guess that's what it means Dignity, right now I'm trying to get a 'feel' for it all if you know what I mean.
OK, photo of anodes from same location, internal in head
Anode other side
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