Engine cut out

[Mudster]

Riding down the M1 this morning and heavy traffic meant I had to stop, whereupon the engine immediately cut out. Restarted fine but as soon as the bike was put into gear the engine died.

So it starts just fine and runs normally in neutral, but dies straight away when put into gear (when the engine is warm). When cold, it runs and rides normally. It's symptomatic of a sidestand switch, but the switch isn't really anywhere that gets warm.

Battery is flat now as I had the hazards on and the alarm kept going off on the back of the tow truck - so not a lot I can check until it's recharged. Just thought I would ask here in advance of a proper check over.

Bike is a k3 Vee.

Anyone had similar in the past?

[greywolf]

The switch can fail for reasons other than engine heat. You can temporarily connect the two wires to the switch to bypass it to see if it is the problem.

[Mudster]

Thanks for the reply greywolf.

Just been reading the service manual and it does seem to point to the sidestand switch. I will short the connector out and give it a try once the battery is charged.

[Mudster]

So I will post any updates on this in case it helps others, but due to the nature of the problem, think I may be on my own with it.

Bike starts and runs fine from cold. I have noticed the fuel pump runs continuously with the ignition on before starting. Pump stops when the clutch is pulled in, but the constant running I don't think is normal.

When warmed up and the fault occurs, the fuel pump relay clicks on and off rapidly (4 or 5 times a second).  I have bought another fuel pump relay and side stand switch (OK, from a breaker) but I think these are symptoms rather than a fault.

[philthunder]

ACF 50 or WD40 sprayed over the switch, and then work the switch. It's a micro switch which though does not get the heat gets all the road crap. If you ride in winter salt will play havock. Wash and oil is the rule. I go over the bike about once a month and treat all switches connectors exposed nuts and bolts. Waxol on non heat areas ACF50 on engine and electricals. Even on the later bikes that use better sealed connectors corrosion can occur, early ones use some very exposed connectors. When I commuted in all weathers, in winter I would hose the salt off every week or more, and spray everything brakes excluded with WD40. When I stopped at the traffic lights I would disappear in a cloud of smoke until it burnt off, some very worried drivers as I filtered by them, got my own back on smokers as I stopped by thier open window     ACF50 improved the burn off when I started using that.

[Mudster]

I replaced the fuel pump relay and the side stand switch, neither of which made a difference.

The bike had (operative word there) a datatool system 3. I have now taken that off and temporarily bridged the immobiliser circuits. Everything seems to be behaving as it should so I think it may be sorted. Need to connect the wires back up, put it all back together and take it for a spin to be sure.

All the alarm connections were quite nicely soldered but then just wrapped in insulating tape. I have bought some liquid insulating tape and proper fabric loom tape which together with some heat shrink should hopefully be sorted.

I am wary about not having an alarm, but it will be quite nice to be able to fill up without constantly faffing with the remote fob.

[greywolf]

Aftermarket add ons that can cause the symptoms of a problem are usually the best place to start troubleshooting.

[Mudster]

Indeed greywolf.

At least while I have the bike in bits and I'm fiddling with the wiring, I can install the bigpie aux fusebox I have had sat around for a while. Along with fitting the usb socket, I am rewiring the heated grips to be rather more tidy. So it has kind of motivated me to tidy things up.

Just need a better soldering iron than the cheap one I have and it should be back on the road.

[Hugh Mungus]

I've had trouble with an alarm but not the same symptoms as yours. Best thing I did was rip it out.
As for cheap soldering irons... I've had my cheap one for 30 years, always meant to replace it and eventually I did. Somehow I still keep using the old one.

[Mudster]

Thanks for the replies blokes.

Got all the wiring back together, just need to put the plastics back on (hopefully this evening) and take it for a run.

Ordered a soldering iron on Saturday afternoon (ebay) and it turned up about 10am Sunday. Pretty good service I thought and worked a treat.

[Mudster]

Well to hopefully bring this to a close, I did a 300 mile trip to Wales on the bike this week, so it would appear to confirm a faulty alarm.

Fuel pump primes and cuts out now rather than running continuously (ignition on and engine not running). On the plus side, I now have enough space under the seat to carry a small compressor to accompany the tyre plugs I also carry.