Bike sometimes not starting

I’ve been having this issue for the past week or so where sometimes it takes a bit of time to start up the bike, although other times it starts up immediately.
). I’ll turn the ignition on, the speedo and headlight come on, I can hear the fuel pump being primed. The side stand is up and kill switch is off (if they weren’t, an error on the speedo would appear). I push the starter button and nothing - no sound or anything. Then after a few tries on the button or holding the button for 5-10s, or switching ignition on or off, the engine finally starts up. This has happened both when I haven’t used the bike for 10 hours and also when stopping at a gas station after an hour’s ride.

I did some tests with a multimeter on the battery:
12.8V when ignition is off and bike cold
11.8V after turning the ignition key
8.5-9.2V when pressing the starter button and the engine starts
On the other hand, when pushing the starter and the aforementioned issue happens (no sound, engine won’t start) I can see voltage rising from 11.8V to 12V and the headlight dimming.

A few months ago I accidentally completely drained the battery (speedo wouldn’t even come on) by leaving the parking lights on the whole day. I managed to revive it with a cheap optimate charger and it was working fine up until now. From what I understand the low voltage during the start would indicate an issue with a battery? Though, I thought the bike would still at least attempt to start the engine even with a lower voltage or am I wrong?

With voltage drop there comes a point where the electrickery (ECU, relays etc) will not respond, at 8.5v while under load from cranking the engine I’d suspect the battery, especially when the start point is a healthy 12.8v. Also dropping from 12.8v to less than 12v on switching the ignition on also leads me to suspect the battery.

I’d expect a good serviceable battery to show more than 10.6v while cranking the engine and no less than 12.2v when switching the ignition (including headlamp) on.


Much appreciated. It’s a few years old already and after running it flat earlier I’m not too fussed about getting a new one.

I replaced mine 6 months back with an online purchase of a Motobatt battery from Tayna Batteries, arrived next day using their free standard delivery option.

Almost certain I bought my replacement battery from Tayna too. In fact it’s twice I think. I’m not sure because they’ve both lasted so long I’ve forgotten.
'93 Trident 900, I know the battery lasted over 6 years, current one is at least 3 and shows no sign of giving up even on the coldest day, parked outside.

It appears the battery was not the issue. Charged up and installed the new battery, but the situation hasn’t changed. Sometimes it starts up immediately without issue, other times it remains silent for 5-10s before finally starting.

Have you tried squirting some contact cleaner up inside the start button.

Could be corroded connection to the starter motor

Read your first post again, seems you could have two issues

As above clean the switch, it will need more than contact cleaner, open the two halves

  1. Check for and remove any corrosion on the contacts with whatever you can get in there ( one of her indoors emery boards?)
  2. Give the internals a good dose of maintenance spray (Triple QX, GT85 or reassuringly expensive WD40) this will remove any debris left from the emery filing, any moisture and some accumulated dirt.
  3. Give the internals a goodly spray of brake cleaner, this will remove the maintenance spray and whatever other debris is left behind in the switch.
  4. Blow dry and pack out the switch internals with silicone grease (grab a cotton bud off her indoors) check you haven’t blocked the drain holes on the underside of the switch with grease and reassemble.

If still no joy check all the electrical connections (positive and negative) to/from switch, battery, starter relay and starter motor.

Tried now, no luck.

It appears to be ok. Cleaned up a bit more to be sure - didn’t help.

I’ll try that next.

By “check” do you mean make sure the connections are clean and there is no visible damage to the wires? So far, I’ve only found a bit of corrosion on the inside of the positive cable that connects to the battery(bottom pic), is that of concern?

I’ve also identified some peculiar behaviour. My bike (suzuki gs650 2008 fuel-injected) requires the clutch lever to be fully depressed when pressing the starter button, which is normal. This morning I was trying to start the bike and got the usual silence, so I decided to play around with the clutch lever a bit. I depressed and released the lever several times while holding the started button in. Every time I pulled the lever in, about half-way (close to biting point) the engine would for a very brief moment try to start before going completely silent again as I finished pulling the lever in fully.

That’ll most likely be a dodgy clutch (micro) switch, you’ll find it behind the lever a the pivot point, as above clean and silicone grease.


It was indeed the clutch switch. There was a fine layer of dirt on the contacts. Cleaned them a week ago, and no issues since. Thank you :+1:


I recommend these for cleaning contacts

@TheMonkey27 reassuringly expensive