Help!!! I hope someone can help. The love of my life is poorly. I'm the proud owner of a 2003 Hinckley built, Carb model, 790cc Bonneville. I tasked myself in maintaining it to the high standards previous owners have. It is in amazing condition (....not perfect but..!!!) & now, has now travelled 13000miles, 5000 of those miles with me. The problem I have now is that the engine will simply cut out dead with no warning. Sometimes, i can travel 1/2mile down the road, other times 5miles. When left for 5-10mins, it'll re-start & continue as though nothing happened for another 1/2 or 10miles. With its latest episode, I managed to determine no spark at the plugs! From advice on other posts, I've replaced the Ignition Pick Up Sensor & the Ignition Coil. I've checked the Clutch Switch & Side Stand Switch & both seem to function correctly. I'm now at the point where I suspect the Ignition Control Unit is suspect. But it costs a fortune & before I purchase any advice will be gratefully recieved. Can they be tested?? Has anyone got a spare I can borrow to substitute to check??
Almost certainly an electrical fault. A carb, or other fault giving fuel starvation would give some warning like power fall off and/or surging. I had a similar fault years ago on a RX1000 which caused much head scratching and turned out to be the sidestand switch. Testing the switch with a meter showed OK but I bypassed it temporarily and the fault disappeared. Static testing is fine but what you can't replicate is the vibration when the bike is being ridden.
Before you go off on a costly exercise looking around the ignition system check that the fuel tank vent is not blocked. I had a similar problem on a carbed Bonneville. The fuel tank vent is a rubber pipe which runs down behind the block and hangs there with another couple of vents from the carb bowls. The vent pipe can become blocked with road crud and that produces a vacuum in the tank. Check the pipe and then cut the end at 45 degrees with the open end facing the rear of the bike. What can happen is that the effect of the pipe hanging in the wind can drag rain water and road muck to the end of the pipe blocking it, cutting it at 45 degrees prevents this from happening. This may not be the problem with your bike but it's a free check!!
Not familiar with this exact model but the symptoms you describe often come about through a faulty crank position sensor.
Thanks so much for the advice & suggestions. I have already changed the crank position sensor . Funnily enough, the engine did seem to run better & smoother but it did still cut out again!
Thanks for the idea. I did try removing the tank filler cap but it didn't help! It's a good idea though & I will double check the hose & cut it as you suggest. Thankyou.
You're absolutely right! I have checked the sidestand switch under static conditions but vibration & bumpy roads.......!! I'll bypass it to double check!
Well!!! Fitted new Ignition control unit & still the same problem! Anybody know what the Diode Pack is fitted & whether this could be the culprit & whether I can test it? It's definitely an electrical issue as when it cuts out, there isn't any spark at the plugs but having changed the Ignition module, Pick up coil & Ignition Coil, what else is there??
I’ve got the Haynes book for my model but the circuit diagram shows an alarm! My bike hasn’t got an alarm so I’m following a circuit, in the book, which is wrong to my bike!! That doesn’t help. I’ve also found the ignition control module pin function layout so that may help to fault find. When looking at it, the module requires a 12v supply which comes from the ignition switch. I didn’t realise that! When my bike cuts out next time, I’ll be checking wiring to the ICM. Not sure now when I can look further as wife is ill but I’ll certainly update the post when I get round to it.
@Dundin Firstly do wish your Good Lady a speedy recovery. And most of the bikes have the wiring to fit the Datatool alarm perhaps that is what you are seeing.
