[Jerakeen]

Having a problem with my bike. The other day, about half a mile from home it died on me and wouldn't restart.
Had all the symptoms of a dead battery. Just wouldn't turn the motor over more than one cylinder.
I had to push it home, which wasn't fun.

Took the battery out to charge it and found that someone had fitted a 12ah battery instead of the 20ah one it should have.
So..... one very expensive 20ah lithium battery later..... and it still won't turn the motor over. It tries, it's just like it isn't strong enough to get it past the compression.

Now over the past couple of weeks I've noticed a certain stiffness and reluctance to turn with the ignition key so I was wondering if it could be something to do with that. Or maybe something to do with the decompression system?

Does anyone have any experience of this kind of problem?

 

[MotoMedic1]

Hi Jerakeen,

• KACR (Decompression system) failure could cause the bike to be difficult to start (no decompression) OR run poorly and maybe even stop running if it fails and continues in the decompression position. But for it to do both at will seems unlikely.
• I recommend removing a spark plug from each cylinder and grounding it to observe spark and allow engine to crank and observe if it does so normally. You could also check compression at this time. Leave the other spark plug in each cylinder installed but remove the spark cap. You don't want A/F mix igniting while checking the engine.
• A failing reg/rec can actually apply a current through the stator and create an opposing magnetic field which could cause difficulty starting AND would cause the bike to stop running and be difficult to start due to a discharged battery.
• Poor grounds and corroded cables could also contribute to a lack of necessary amps/current to get the starter to function.
• The starter itself could be weak and need serviced, refurbished or replaced.

 

[Jerakeen]

Hi Jerakeen,

Thank you.
I really hope it isn't the starter. I looked on Fowlers and the list price is over 800 quid but that's academic because they don't have any.
I've got next week off so I'll work through your suggestions.