replace rectifier ?? 140 johnson 1983

[billybaja]

I am not sure it is bad I am only "guessing" .. I tried to read a few of the threads but I am still not sure how to check the stator hopefully it is not that , and is the rectifier>> The battery has not given me a problem yet but i have only run it on the muff`s and took it out today for an hour or so ran great but only getting 11.97 at idle and maybe 11.98 or 99 at wot.. I am really hopeing it is the rectifier but if I do replace it and turn`s out it is the stator would I ruin the new rectifier ?? I have to learn more about the elec sytem ,even though the battery is able to start and run the engine I think it should be putting out more what is going to happen if I turn on the light`s?? I do have a volt meter or multi meter so maybe someone can point me towards a procedure check for rectier and stator ?? I have a seloc manuel but really have not found it to be too helpfull .. any advice is appreciated Thanks Bill

 

[marinemech1]

Re: replace rectifier ?? 140 johnson 1983

Battery voltage should rise after start up around 13 or so.
To test rectifier remove all rectifier leads and check for continuity between one wire and ground...repeat for all wires..note reading (continuity or not) try to use an anolog meter as digitals give funny readings.
Now reverse meter leads and retest all wires
It should have continity in one direction only. If your results vary replace rectifier.
P.S. I've only replace 4 OMC stators in 29 years as a tech so odds are its the rectifier.
(make sure battery is connected properly as a reversed battery immediatly fries the rectifer)
Wayne

 

[billybaja]

Re: replace rectifier ?? 140 johnson 1983

ok checked all my connenctions all are really clean I did realize the battery is a little low so I am going to fully charge it and then start over I am pretty sure I can check the way you said this is the tird motor I had on this boat within a two week period so I was pretty sure my connections were ok..but that is how I noticed the volt`s were low I am hopeing it is the rectifier motor run`s great otherwise,, Thanks for the help Bill

 

[billybaja]

Re: replace rectifier ?? 140 johnson 1983

Hey Wayne thanks, I am haveing a problem i.d the engine year I believe the rectifier is partiallty under the flywheel in the center of the block just above the bubbleback, it is a square looking box type piece with two yellow wires one yellow is solid the other yellow has a gray stipe ,one gray with a yellow stripe ,one solid purple and one red wire ..total of five wires and looks like six mounting bolts., I do not see a dedicated ground They all go to the terninal bar on the telltale side of engine . Would you normally remove the flywheel to change this piece?? I had a 1980 and the rectifcier was a round looking piece? they are about 30.00 on the iboats parts hopefully I am describeing the right piece . I gave the numbers from the welsh plug on the forum and was told it is probally a 1984 140 hp crossflow engine.. I can remove the flywheel have almost every tool and a air compressor do hobbist auto work I am not a mechanic but pretty handy

 

[marinemech1]

Re: replace rectifier ?? 140 johnson 1983

you are describing a rectifier regulator... not just a rectifer
find model number of motor to identify year...omc used different rec\regs over the years some are not too bad around 100.00 some are 400.00
yes u need to pull flywhell to change it.
Wayne

 

[billybaja]

Re: replace rectifier ?? 140 johnson 1983

thanks again Wayne I really have to go over it again it might not be the rectifier -regulator ., I should have started right at the battery it was low took me 2 day`s to charge it with a trickle charge I heard it is better to charge them that way.. I am hopeing it is the battery ,yesterday even though it did not have a full charge I started it up and used he volt meter and had approx 12.87 volts at the battery it was raining and I really did not feel like getting soaked I am going to get back on ot tomm. Thanks to all for the great feedback really learning alot from forum and manual.. Bill

 

[Vic.S]

Re: replace rectifier ?? 140 johnson 1983

Charge the battery at its "bench charging " rate. Modern low maintenance batteries will often not respond to a trickle charger if they have been heavily discharged.

Either use a modern automatic multi-stage charger or use a basic non automatic one until you have a reading of at least 14.4 for a couple of hours.

Let the battery stand for 12 hours and check the volts with no load or further charging. If it is not above 12.7 try charging some more. If you cannot get a reading after it has rested for 12 hours of around 12.7 the battery is most likely dead.

Assuming you have successfully charged it get it on the boat and start the motor.

If all is well the volts should rapidly rise as the battery is recharged to around 14 volts if you a have a regulator, which it sounds as though you do. (without a regulator they will rise even higher)

The simple non regulated rectifiers can be tested as outlined above or as described in more detail on the Engine FAQs board. If using a digital meter use the "Diode test" range not an ohms range.