I was recently given a Yamaha 3.5 air cooled outboard engine. Looked like it had been out in the open for many years. I had to drill out two of the screws holding the cowling. However after dismantling the carburator cleaning out and priming, the engine started. My problem was to stop it as the stop button is not working and I cannot see how it is removed. Now I would like to do a bit more work on the enging. I have looked online for a service manual but cannot find any for this engine. Would any member have a manual for sale or be able to supply a copy. Any help would be appreciated.
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Hi,
I bought a service manual for this engine from a dealer less than 1 year ago. I got the impression that a good parts dealer will hunt down a copy. Try BHG in Lymington if you are in the UK.
The stop button is a bit awkward to repair (I have done a couple recently). Remove and dismantle the handle taking photos at every step (to aid re-assembly - the photos in the manual are very poor). Also dismantle somewhere that flying/stray bits can be easily recovered! As well as facilitating repair of the stop button dismantling allows a thorough clean and regrease of the throttle mechanism.
The button itself should provide a short circuit between the magneto wire and 'chassis' when pressed but lack of maintenance causes the faces of the contacts inside the pushbutton to corrode and go open circuit when in contact. The switch body cannot be disassembled to expose the contacts so I have used patience, soaking in WD40 and much 'wiggling' to re-establish a good short circuit. Don't reassemble until you are convinced that a reliable short circuit is possible. Alternatively, try asking a dealer if they can still get parts - remember that the Mariner is virtually identical so their spares will probably be OK.
Parts lists for both Yamaha and Mariner are available for download somewhere on the web.
Cheers
Bob
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I'm not clear how far you stripped the switch from the handle so I'll take it 'from the top'. (I'm working from memory because I don't keep the engines or spares here at home). I'm assuming you have separated the handle, along with the throttle cable and stop wire from the rest of the engine. See attached drawing.
1 With the handle in pieces, it should be possible, with a bit of jiggling, to draw the stop wire through the sheath (28) that carries both stop wire and the throttle cable from the engine to the handle.
2. Inside the handle there is triangular washer (26) holding the switch assembly in place. In badly maintained motors the nut (25) can be heavily rusted and may need soaking/persuasion.
3. The switch and its wire will then come free of the handle.
4. The switch assembly can be further dissected by carefully prising the two metal tags through 90deg and pulling apart the outer casing and the rubber of the pushbutton.
5 This should leave a brass casing with a nipple which is held in by compression of the brass casing. This casing can't be further disassembled without damaging it. Inside is a spring/contact which easily corrodes.
6. I have successfully recovered two of these switches by inserting the WD40/switch cleaner straw between the nipple and the casing and then repeatedly agitating, manipulating, flushing, agitating etc
7 If this hadn't worked I would have glued something temporarily to the nipple to allow rotation +/- 90 deg to scrape clean the spring winding inside
Hope this helps
Cheers
BobAttached FilesLast edited by ribvanw11; 06-10-2011, 10:49 AM.
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Try the dealer mentioned above if you are in Europe otherwise
these guys say they have 10+ in stock (assuming they are identical to the Yamaha part?)
Mercury Quicksilver 87-80184M SWITCH 87-80184M @ MarineEngine.com
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There are two wires coming from the flywheel, area one goes to the coil and to the stop button. Any idea what the second white wire is for. Should there be a condenser fitted somewhere across the points. I would like to source some touchup paint any idea what the colour of this engine is or do you know if there is there a car touchup paint a close match. Thanks again for your help.
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Underneath the fywheel looks like this:
The condenser is the cylindrical metal can.
The white wire is connected to 'chassis' under the flywheel and is not connected at the other end on any of my motors. Here is the (modified) diagram from the service book
Sorry but I have no idea about the paint colour. Please let me know what you find out.
Cheers
Bob
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Roland
You can download the information from here
http://www.autocd.info/autocd/OM/3.5...4-28198-E5.PDF
Cheers
Bob
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Bob.
Just returned from a trip to Cornwall and when I checked the forum I was delighted to find the link. It makes the job a lot easier. I managed to pick up some new bits and some old bits on my travels but unfortunately not all I needed. I was looking in particular for the cowling and the spark plug cover but what was on offer was in poor condition.
Many thanks again.
Regards
Roland.
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