I pulled it out of the garage last night, mounted it on a bit of wood and dangled the leg in a bin of water.
I changed the plug for a brand spanking new one and sprayed all the connectors with WD40. Several pulls on the cord later and it was obvious that it wasn't going to go. I was hugely disappointed as I had assumed that it just needed a new plug.
The first suggestion was to test for an air gap spark.. I followed the instructions and made this super tool out of wood and nails.. all very industrial revolution looking :) Well it proved there was little if anything coming down the HT lead.
So, This morning I scrabbled around the garage, house and loft looking for long forgotten pieces of electronics. During my searching I found my old Oscilloscope, this should be able to measure any signal being generated.
My other job for today was to examine the trailer bearings. I had quickly packed them with grease before taking Jelly Bean to Ipswich, I had noticed that there was some staining but as the Fantasie 19 is a relatively light boat so I wasn't too concerned. Ciao Bella is much heavier so the bearings will have to be perfect. On top of that, my brother will be doing the towing so the trailer needs to be 100%
One thing that did make me laugh was this wee fella who'd been living in the barnacles and weed on the bottom of my tender :)
A passage stolen from http://www.pearsonariel.org/discussion/showthread.php?737-Nissan-6-HP-4-cycles/page3
ReplyDeletePasted here for future ref.
Nissan, Tohatsu, Merc 6 hp Starting / Exciter Coil
To continue on with comments on the 6 hp four strokes all made by Tohatsu, I've had mine running since 2004 and have some comments on maintenance. Everyone knows by now that its a good idea to drain or run excess Ethanol 10% gas out of the carb if you aren't going to use the outboard every two weeks or so. Gas stabil is almost a must because the ethanol absorbs water. Over the years, I've found that the common reason my motor wouldn't start or idle well is bacause of clogged jets from fuel. In Houston, with 95 degree temps every day in the summer, it doesn't take long to evaporate all the fuel and leave the gunk behind in the carb. I've cured any problems by disassembling the carb and soaking in carb cleaner. I've found that the spray cans don't do a complete job. However, I recently found that hard starting and engine dying was because of an ignition problem---- not dirty carb issues. I used a spark tester and found I wasn't getting a spark on each pull of the starter roper. I got out the Tohatsu factory manual (the real deal which I purchased from Defender) and tested the resistance of the ignition coil, the exciter coil (which sits under the flywheel) and the pulser coil-- which is at the edge of the flywheel under the starter rope hole. Most of the coil resistance tests allow a plus or minus 20% reading from the factory spec, and still be good. But my exciter coil was off spec. The exciter coil generates the low voltage current, sends it to the CD unit (that little black box with all the wires leading to it). The CD unit stores this energy until its told by the pulser coil that its time to fire the plug. The CD then sends voltage to the ignition coil (roundish black epoxy coated coil connected to the spark plug wire) which then steps up the voltage to fire the plug. The factory resistance of the exciter is supposed to be 119 ohm plus or minus 20%. Mine was reading 78. So there was a developing short somewhere in that coil, and it wasn't generating enough voltage at low rpm or, most importantly, when I pulled on the starter rope! I put in a new coil (they are about $30) an now the motor starts on first or second pull-- like when it was new. The hardest part of this job was getting the flywheel off. You can read online on how to do this properly. You can mess up the flywheel and do some real damage if you don't use the right tools. With the right tools, its easy.
As you engine ages, and it starts getting harder to start and idles less reliably, check you coils. I didn't think modern coils failed very frequently, but my experience shows that they can and do.