With the wife working away over the Easter holidays, I tried for a bit of an Easter miracle yesterday (Easter Monday), and attempted a resurrection by getting the 1VJ's engine running. Unfortunately, I didn't have much luck and ran into a few issues.
Issue 1 - Ignition wiring - very week spark.
After initially sorting out the issue with turning the engine over via the kick starter (see issue No.2) and doing some basic mechanical checks like setting the tappet clearances etc, I started to have a look at the electrics and ignition. Things looked quite promising and kicking the engine over gave a reasonably healthy spark at the spark plug. I left the electrics at that, and proceeded to removed the carbies and fit a set from a later XT600 that were in better condition (slightly cleaner) that I thought should be good enough to get the engine running. Unfortunately, once I had the carbies fitted the spark that I previously had, had disappeared. Although there was no spark visible, doing a "finger test" I could feel a very week voltage at the spark plug when I gave it a decent kick. As I don't have a manual for the bike, I downloaded the wiring diagram for the 3AJ from the forum, as I suspected that it would be similar and I could at least use it as a starting point, and hopefully with it and 40 odd years experience in the electrical / electronics industry I would be able to nut things out.
Well, after many hours and a lot of failed theories, I was getting nowhere. I then found a circuit diagram on the net, reputed to be of a XT600 CDI unit. With this diagram, and another CDI unit from the wreck of a 1988 XT600 that has been lurking in the back of the shed for some years, I started to test the CDI unit on the bike. After a while it was starting to look like the CDI on the bike had failed. I still can't workout why it had spark initially then failed, it will remain one of lifes great mysteries. So, out with the side cutters and crimping pliers and the existing plugs were cut off and the wiring altered to accept the 1988 XT600 CDI unit. First kick with the "new" CDI and there was spark
Many many kicks later, it still hasn't run, but it has sounded close, including one very loud back fire that resounded through the shed so loud that I though the neighbors would be calling the police to investigate a shooting.
Next step will be to remove the carbies and give them a really thorough clean out, and try and get the electric start working, as I am just not cut out for trying to kick the thing back into life. This leads to issue number 2.
Issue 2 - Starter clutch
As posted earlier, when I first got the bike a few weeks ago, it was assumed that the engine was stuffed / seized. After removing the clutch cover and finding everything looked reasonably OK, I was able to turn the engine over using a spanner on the end of the crankshaft. While I had the cover off I removed the plates from the clutch to free them off and while playing around checked that the kick start mechanism was OK and the the gearbox turned over OK. When I turned the crankshaft I I could hear the starter motor turning so I knew that the problem was on the LH side and not with the clutch or kick start mechanism
Yesterday, I pulled the alternator cover off and found that the Starter Ring Gear was "seized" in the free wheeling bearing on the alternator rotor. I disassembled the Starter Clutch assy, and as there were no obvious signs of anything broken or badly worn, I assumed that the ring gear was stuck/seized due to having sat for 20 odd years, as after cleaning the assembly with solvent it all appeared OK, i.e. it would lock when turned in one direction and free wheel when turned in the other direction.
Everything was OK, and I could kick the engine over, however later that morning while trying to kickstart the engine, the Ring Gear jammed/stuck in the free wheeling bearing on the alternator again. (Note, that I had not tried to use the electric start at any time). I remover the cover and rotor and freed up the ring gear again (it was jammed quite tightly), and again one freed up, would work perfectly on the bench while being turned by hand. After reinstalling the assembly I had another go at kicking over the engine, and it jammed again. This time I heard a distinct "clunk" as it jammed. It freed up momentarily, and then, with a "clunk" jammed again. I have currently removed the intermediate gear between the starter motor and the ring gear so that I can continue with trying to sort out my electrical / ignition issues.
So, the question is: Is there a recognised problem that causes the Starter Ring Gear to jam in the free wheeling bearing in the alternator rotor / flywheel?
An hints and/or suggestions greatly appreciated.
