Power outlet

[Skibiker]

Hello all,
I have just bought a small day boat with an old Johnson 15hp 2 stroke outboard fitted to it, the engine has a socket on the side to charge the boat battery but the guy at the boat yard wants 30GBP for a plug to fit it, is this a fair price? or should I be looking elsewhere, also between the choke and the pull start there is a knob that rotates through 360 degrees I have no idea what it does as the engine is old and has no instruction book, you will have gathered by now I'm new to boating.
Any help would be appreciated, I'm based in the UK.
Regards Skibiker.

 

[Vic.S]

Re: Power outlet

If your engine has socket on the side Id guess that is an AC output for running lights. For battery charging you'll need the charging adaptor that plugs into there which includes the rectifier. That'll be a lot more than 30 squids.

You dont give the model details to check but some have a three wire output from the stator (to that plug) others have a two wire output.

Generally models with an DC output for battery charging have a rectifier under the cover connected up to a terminal strip and the stator output, and maybe with a lead, rather than the socket, for connecting to the battery.

Assuming yours is just a AC output you can buy the appropriate rectifier, but that'll still cost more than ?30.

If it is just a two wire output you could make do with a suitably rated bridge rectifier from one of the electronic components suppliers.

If its a three wire output you need a 3 phase rectifier, which means buying the proper one or making one from 6 diodes.

Tell us your full model details, year and pref model number, then we know what we are talking about

Circuits for a three wire output:

 

[Vic.S]

Re: Power outlet

Sorry missed the knob. That's the slow running mixture adjustment. Should normally be set to its mid point.

Full instructions for adjusting the needle valve: http://forums.iboats.com/showthread.php?t=167352


Dont know where you go for spares but users of the YBW forums have found Willsmarine in Devon and Outboards Direct (AKA Oakley Marine ) in Brighton good for mail order. Google will find them, or ask for links

Also

witha 15hp you'll need to know about http://www.sschapterpsa.com/ramblings/OMC/OMC info.htm



PS just realised if you have an electric start model the rectifier may already be fitted ! But its not is it ?

 

[Skibiker]

Re: Power outlet

Hello,
Many thanks for the info it's much appreciated.
unfortunately I have no information on the engine other than it's an old Johnson 15hp 2 stroke, it runs fine but I did not realise there were no instructions or model details for it when I bought the boat, however it is a 3 wire socket on the side, but the guy at the yard wanted 30GBP just for the plug? Is it a standard part which I can purchase elsewhere and could the other bits required be purchased from Maplin, I'm no stranger to a soldering iron! I just felt when I asked the price for the plug he was thinking up a number.
The idle control is set in the middle but the engine does stop if I leave it on idle more than a minute or so
Regards Skibiker.

 

[Vic.S]

Re: Power outlet

The three wire socket confirms that its an AC output.

Looking at the Accessories parts list the Johnson/ Evinrude plug and lead appears to be 60 US dollars

A complete battery charging kit Including rectifier , mounting plate, cable, fuse, etc that will plug in to that socket looks like 75 USD. That's more reasonable as it includes the correct rectifier.

A rectifier on its own that could, I think, be mounted on the side of the block would be 50 USD although a non oem one would be less a terminal. The official terminal board with screws would add another 15 USD.


The alternative to buying official parts if you have the knowledge of electronics to do it is to make up a rectifier assembly using 6 suitably rated silicon diodes ( P600A from Maplin at only 78p each ??) to the design in my diagram and find awy of connecting it up without buying the plug. Mind you if you save $50 by making a rectifier you can afford to pay ?30 for the plug

Find the model number of your engine and double check every thing above with the parts lists at Shop.Evinrude.com In the absence of a year I have taken figures etc for a 1984 model.

Find your model number, It should be on a plate on the transom clamp, if not it may be on a core plug (a disc bigger than a 5p piece but a bit smaller than a 10p) on the engine. Once you have the model number you can identify the year, As far as i can see 15 hp models have been made continuously since about 1974 and a few odd ones before that.

Let us know how you get on!

 

[Skibiker]

Re: Power outlet

Hello,
Many thanks for your advice it's helped a lot, I assume though if I make up your rectifier circuit it would be advisable then to couple it to a 12volt in 12 out variable output battery charger in order not to continually over charge the boat battery? I will let you know how it goes.
Regards Skibiker.

 

[Vic.S]

Re: Power outlet

Its normal for small outboards, not to have a regulator. Larger outboards with power tilt and trim etc have higher current output stators and then have a combined regulator/ rectifier.

You could fit some form of regulator but personally I would not bother, I'd stay with the thousands that dont! Why not give it a try without. If you find you are topping up the battery electrolyte too frequently then think about something different.

 

[Skibiker]

Re: Power outlet

Cheers.