starting issue

[jigs_imp]

Hi, I'm having a serious issue with my 2015 A CB1100, the bike won't start unless you sit on it, once started and you climb off the engine dies, both oil warning lights come on and stay on until you sit on it, the lights go out and it will start, but when riding it cuts out probably due to weight issue on the moving bike! Please, please help!

[GoldOxide_imp]

Sounds electrical for sure.

Start with tracing the side stand switch - maybe?

Next, maybe the kill switch wiring through the head stock?

[Lord Popgun]

Well this one is weird. Max might have an idea. I’ll have to look at some wiring diagrams first.

Checking the sidestand switch would be a good and easy first start though.

[the Ferret]

Have you made ANY changes to the bike lately? Wired in a GPS, installed heated grips, new led headlight? Anything prior to the issue starting?

[Lord Popgun]

Need to know what Ferret asked.

But, parts involved are Neutral switch, clutch switch, sidestand switch, ignition switch, Engine Stop switch (the kill switch), Engine stop relay and bank angle sensor.

I’d check the sidestand switch and the clutch switch. A good portion of the above is connected to the ECM of if you have been under the tank, check the ECM is plugged in properly.

Just for giggles you might want to check the 20amp fuse and main 30 amp fuse to make sure they are OK and seated properly. And yes, fuses can be a problem even when they are not blown.

[j3gq_imp]

I am a little confused about your statement "probably due to weight issue on the moving bike! ", where did you get this from ?
If we set this aside for the moment, can you please define these configurations:
A) when you say "unless you sit on it" : means sit on it with both side stand and main stand up ? or not ?
B) when you say "when you climb off" : means the m/c now on which stand ?

Next please try this and report back : put your bike on the main stand and start the engine, if it starts - get on and off the bike. What happens ?

[Tev62]

Ask yourself what parts of the wiring are likely to be affected by physically sitting on the bike and start with those first. All of these other switches are good places to look but what do they have to do with sitting on/off the bike? What is directly under any part of the seat, any wire, loom being pressed and shorting on the frame or other part? Is there a relay or or fuse box being squished or distorted anyway by the seat? After that, what wiring could be disturbed by the movement the suspension, forks or swingarm. I take it you have tried the obvious too, your seat isn't making a good connection on the battery terminal by pressing on it I take it?

[GoldOxide_imp]

Yeah, in light of Tev's comment, that is why I mentioned the stop/kill switch wiring as it passes through the head stock area.

When one sits on a bike, most likely the handlebars will move in some fashion. Maybe the associated wire got strained and broke recently? I don't know. What I do know is it happened to me once and it was a hard problem to solve. However, sure enough, it was an open connection in the wiring mass going into the headlight and would make or break each time I turned the handlebars, sometimes just a wee bit.

[max]

Here is a diagram, the pink highlighted parts in the vertical line are required for starting, the red engine stop switch and the bank angle sensor stop the supply to the engine 12v bus.
instrument panel lights have their own supply fuse and stay on when the engine stops.



is the fuse box intermittent when it's moved?
( under the seat )

The oil light lights up when the engine stops, which other light do you mention?

The sidestand can be up or down when the bike is in neutral ( green light ) and does not stop the engine, the red engine stop switch does as well as the engine stop relay in the fuse box and the two fuses, one in the start relay housing (20a) and the start 10a fuse.
The only two wires that can stop the engine are running from under the seat to the right handle bars.

If you don't sit on the bike and turn on the main switch does the fuel pump run as per normal?

If the orange mil light is on the engine bus ( ignition, fuel and e.c.u. ) is powered up fine otherwise the m.i.l. light will be off.

And don't overlook a loose battery connection.

[jigs_imp]

Thanks guys for all your input, yes I have disconnected the battery and cleaned connections, that isn't the problem, the 2 red warning lights are oil pressure and oil temperature lights, when sat on the bike on or off the stands it will?start with no issues on dash, once you get off the bike or stand up weather on or off stands the 2 warning lights come on, the engine shuts off and the starter won't turn! Very very weird! Will check fuses and wiring under the seat and report back! You guys are diamonds