Mech

Yup. A squirt of CRC or WD40 once every now and again will keep the new switch working.. if it's a genuine Kawa switch anyway. Non-genuine, perhaps not. Silicon though can give off fumes that corrode, and it's likely to keep the water that does inevitably seep in trapped in. Silicon is awful stuff !!

Ok. Things like to be used.. They get rusty and unreliable sitting around.

I doubt silicon will keep the water out for long. I'd use vaseline or some soft seal, but you need to be careful where it goes if the starter is a press contact, rather than a sliding contact. Press contacts get dirty easy and even vaseline can stop them working. Sliding contacts cut through vaseline or soft seal so those contacts can be covered in the stuff.

Yeah, what Gw says...

Yeah it could be the solenoid, and a good test to verify that, is to give it a hard tap with a screwdriver handle, while holding the start button down. There is a danger though that if the solenoid earth is bad, or the start button does have a bad contact, or the isolation relay has a bad contact, or, in some bikes, the kill switch has a bad contact, causing low current to the solenoid windings, then the hard tap might just be enough to get the solenoid to move and operate with the low volts to the windings.. The best check for bad contacts or connections is to look for voltage drop through that windings circuit. If the voltage drop checks all pan out ok, then try tapping the solenoid.

If you can split the nut it will come loose. There are tools called nut splitters. You'd have to get one that could fit onto that nut if the space is a bit confined.

Definitely check the start button. Most start and kill buttons are poorly weatherproofed.. if at all !

Well the standard procedure is check there is resistance through the cdi charge windings and the cdi trigger windings down on the stator plug, then crank it over and check there is some voltage produced at the charge pins and a momentary voltage at the trigger pins on the plug. You need a good spec digital gauge to detect the momentary trigger voltage, but an analogue gauge the needle flickers and is easy to see. , If there is voltage in both windings then we check they are getting to the cdi unit. If there are those two voltages, and perhaps a 12v feed if needed, plus earth and a disconnected kill or a connected kill in some cases, then, if everything is ok, the spark should be very reliable. I would be suspecting the switches or the wiring. There are things that can go wrong in the engine though, like flakes of metal, or metal dust build up, that can short out the magnetic field between the magnets in the flywheel and the winding cores. If it's a flake of steel it can move and intermittently kill the trigger coil's output. I'd check for voltages out of those two windings, then look carefully at the wiring again.. short perhaps to frame ? Oh, and is the dash still flashing ?

Ha.. Ok. Good man.

If the bendix has a sprag/one-way clutch, it may be that playing up.

You used the key ! The key switch has dirty contacts or lost movement in it's mechanism.

The fuel starts evaporating out of the oil once it gets just slightly heated and the fuel filled fumes drowns the engine... just like flooding. Seen it plenty of times. At the same time the thin oil, carried with this excessive amount of fuming, gets past the usual oil/air separation systems and fills the air-box with oily fumes which separate out in the box. The float needle allowed the sump fill, but may not be the cause. Float needles can seal plenty well enough for maintaining the fuel level during a days use, but let enough leak through to flood an engine over night if the fuel tap doesn't get turned off. If the needle valve worked perfectly it wouldn't happen, but a lot of needle valves that seem to work just fine during the day can fill the sump if the tap leaks. I'd check the fuel tap because that test is so simple.. Turn it off, pull the hose and watch for a drip. I'd open and close it a few times checking it closed every time. If the tap is working ok then I'd check how the bike runs and consider cleaning the carb, but I'd check whether the float level seemed to be ok and was ok during a days use.. It is possible that someone forgot to turn the tap off one day, or, the tank breather didn't work ad pressurised the tank and caused the problem.

This is what I'm looking at. output.pdf

Do you have a wiring diagram ?

The diagrams I looked at described both the starter relay and the starter solenoid as "relay". I think we should describe the one with the starter cables attached as the starter solenoid.. to avoid confusion. In the diagrams I looked at the colours were different but the solenoid had two small wires operating it, one of which was black, and that one went to the starter relay and bought the 12v to the start solenoid to close it's contacts. The other one was supplying an earth to the solenoids windings. Then there was a white wire which in my diagram was shown as being connected to the battery's positive post, but which could be attached to the solenoid's battery cable post/terminal and it would serve the same purpose of supplying 12v power to the main fuse and then the bike.

Those other two wires only act to kill the ignition. If you look at the switch(#3) in the diagram, it's showing that when the key is is the on position, the power is switched to the brown wire(which feeds starter and lights etc), and the ignition kill wires are not connected. When it's in the off position the kill wires are connected and the power wires are not connected.

Well if the bike is like that diagram I posted, and the two wires you are connecting are the red and brown wires that go to part #3 in that diagram(which is the key switch), then it means the key switch has a bad contact or bad connection in it or it's wires/plug. Your wires are just by-passing the contacts in the key switch.

The fan gets switched on when the oil temperature gets high. The fuel pump gets turned on when you first turn the key but then switches off unless it's getting a pulse from the cdi. The pulse from the cdi is the same pulse that fires the ignition coil, so if you have spark, you have the required pulse to operate the fuel pump relay, you just need to ensure it's getting to the pump control relay. When wires have no continuity, or have high resistance, it's almost right at the end of the wire where it crimps into the metal terminal, it either corrodes or breaks the wires inside the insulation. Wires do sometimes break if they have been chafing for a long time on something and worn right through the electrical tape, insulation, and then the copper wire, but that's easy to spot by the frayed insulation.

You operated a switch.. There's a bad connection/contact somewhere.. You need to be doing what's called a "voltage drop test" on every suspect part and all the wiring. The test is to check for any voltage drop along a wire while it's got power in it and flowing to/at the wires's usual load. Look up voltage drop test and it will be explained and probably demonstrated online.

It had the problem before the overhaul, so it's probably not blow by or bad rings. You'd have to fit the wrong size rings, or break a top ring, to get enough blow-by to cause the filter housing to get oil in it. And, if it starts easily, it's got enough compression. So.. blow-by, by itself, shouldn't be a problem once/if you get the engine running. Neither blow-by, nor oil in the filter housing should cause the engine to stop after only a few seconds. If the air-filter was so full of oil that it choked the engine, then it probably wouldn't start easy, and it wouldn't start easily after the oily filter had flooded it of fouled the plug. If the oil in the filter housing, and the cutting out, are related, it will be fuel in the oil. There is a chance though that the two are not related. If you have a timing light you could connect that up and watch it to see if you are loosing spark. If you don't have a timing light you can fit a plug to the plug lead, and then rest that against the fitted spark plug so that the spark has to jump the first gap to fire the second plug. If the spark is good it will do that jump and the bike will run, and if the spark dies you can see it on the first/external plug.

Cdi coils should have almost no resistance on their primary windings. 0.6 Ohm would be about right. Coils for switched 12v have resistance.

Good work finding the pushed back pin.. Time after time it's the wires not the electronic bits.. or Switches.. That flickering could be a key switch, or perhaps the kill switch, with dirty contacts. I'm pretty sure the flickering will be because the voltage to the gauge is dropping below the about 5volts the internals of the gauge usually work on.

I think these will be right.. The manual is for 86-89. If it's not right it probably means your bike is the previous model, up to 86. 86wiring.pdf 86 fuelpump.pdf

You need a battery too. That dash display going screwy is because the voltage is dropping too low when you are using the starter. The charger isn't supplying enough power to run the starter. If it cranks too slow because of not enough battery power then it might not make spark, and if the cdi uses 12v it won't work at the very moment it needs to, just as the piston's coming up on compression stroke and the dash dies.

You could try riding it in low gear till you hit the revs you do at 20 in high gear. If it keeps going past those revs then it says it's not a rev limiter. Then if you rode it down a hill so it had no load on it, and it still wouldn't go over 20, then it really looks like being a speed limiter. It's possible it has a speed(or rev) limit by design, that you've triggered by accident, either in the wiring or the ecu repair. If you figure which limit it is, )if it is not a load limit), then it might be a lead where to investigate.