What are these wires??

[Dbldutch]

Sorry for the blurry photo - it's the yellow/green wires that I'm interested in


They were connected to a yellow/green pair of wires taped to the clutch cable on the left handlebar - these were stripped a bit and just about in contact with each other. I've discovered that the bike won't start without them being in contact but runs with them not in contact, so can I just plug the two ends into each other at the headstock? Or is this leaving part of the starter circuit connected all the time that shouldn't be? What is/was their purpose?

I'm chasing gremlins at the moment,  thought this might be one of them 

[BigBob]

It`s part of the clutch switch, and as you say, the bike won`t start without them being connected.
On all my Bigs I`ve  just connected the two ends behind the headlight as it means there is one less thing to go wrong.
Connect the two ends at the loom together and forget about it, as  it`s just stupid Japanese elf n safety gone mad.

[Dbldutch]

It`s part of the clutch switch, and as you say, the bike won`t start without them being connected.
On all my Bigs I`ve  just connected the two ends behind the headlight as it means there is one less thing to go wrong.
Connect the two ends at the loom together and forget about it, as  it`s just stupid Japanese elf n safety gone mad.

Brilliant, thanks Bob - I'll tick it off the list, and keep digging to work out why the bike won't run right. First one today is to figure out why there's quite so much noise from the rotor side of the engine

[spendango]

It`s part of the clutch switch, and as you say, the bike won`t start without them being connected.
On all my Bigs I`ve  just connected the two ends behind the headlight as it means there is one less thing to go wrong.
Connect the two ends at the loom together and forget about it, as  it`s just stupid Japanese elf n safety gone mad.

Brilliant, thanks Bob - I'll tick it off the list, and keep digging to work out why the bike won't run right. First one today is to figure out why there's quite so much noise from the rotor side of the engine

Balancer chain !!

[Dbldutch]

Balancer chain !!

I ended up spending the day dealing with electrical gremlins (mostly of my own making as it turns out), and checking the fuel system - it crossed my mind that things like the tank breather probably haven't been looked at for years. The backward fitted (and totally clogged) fuel filter wasn't really a surprise

That done, symptoms are still exactly the same - the bike idles perfectly, but shudders when accelerating from low revs. If you keep the revs a bit higher it runs fine* until you take it up to about 70/80mph (on the clock), then it starts hesitating - possibly detonating - badly enough that I keep a hand on the clutch for fear of it seizing. It keeps doing this off and on from then on, even when you slow down.

I've checked thee fuel system through, that's all good and the carbs are recently rebuilt (It was doing this before they were rebuilt, so no reason to suspect they're at issue)
Valves have been checked recently
Oil is plenty, and clean - I haven't checked the cooler, but I can't imagine the bike overheating at speed even if it was blocked
I haven't pulled the plugs - I was hoping to avoid taking off the bodywork, but I guess there's no choice now
The TPS wiring looks as if it's been a bit hot from the exhaust in the past, but is (on cursory inspection) intact. I've assumed this isn't the issue as the problem can come on at constant throttle.
There is a horrible amount of rattling from the rotor side of the engine while running, and a sound like a spring catching and the starter pinion spinning when I stop the bike

BEFORE I take the rotor cover off, what jobs do I need to do while I'm in there, and what parts do I definitely need? I'm guessing the gasket for sure?

As a (possible) aside - I noticed the bike has a Mitsubishi ignition module. Mitsi car ecu's of the same vintage were known for blown capacitors, is this something the Bigs suffer from?

Sorry for the rambling post, but I really want Godzilla running, she's a hoot to ride for the brief moments she's running well!



* I say runs fine, it's lumpy as anything compared to my 4-cylinder bike, but I rather expected that!

[Dbldutch]

Okay, so I had a little look today after RTFM - pretty straightforward, I tightened the very sloppy balancer chain, and it's a bit quieter - less "kickback" on the starter too when I stop the bike, but this might be coincidence . Haven't taken it for a test-ride, ran out of time, so don't know if it's running better. Rereading after having done it I think I didn't do it quite right, so I'll try for a little tighter when I have a minute. Good news is that it all looks lovely in there and cam chain tension is good, so not much chance of it having jumped. Balancer alignment marks also all good.

I now understand how it would affect how the bike runs - with the cam chain being driven off the balancer chain the timing could go off with the chain slopping around. I still don't understand why it's fine for a while and then crap, but I'm sure it makes sense to someone

Plugs are black as the inside of a black cat on a dark night (in honesty, I only pulled the easy one today). Spark's okay but not blinding, the bike's not using oil, but is running a little rich (which I don't mind). I'll replace them with some hotter ones (as per manual) and see where we're at.

One question though - the two little cogs that fall out when you open the casing didn't have any rings either side, they just run against the casings. Is this correct? The parts diagram I found doesn't show any, and the manual doesn't mention any. I guess they only run very briefly if I've understood how it all works, but they'd be dryish when they do?