Cold start issues

[Elskus]

Hi, I am new to the cbf1000.
I have a 59 plate CBF1000AF

It has trouble starting from cold, will fire but only after a number of attempts

Measured the battery voltage this morning after leaving overnight and got the following:
10.2 reading cold
Dropped to 8 when starting
Once started reading 11 on tick over (1000rpm)

When measured warm yesterday was reading:
12.4 engine and ignition off
11 on starting
13 on just above tick over (2-3k rpm)

It has been regularly serviced and has 43k on the clock

From the wealth of knowledge here, is this likely to be a battery issue or maybe new plugs?

[Art]

 

First off I'd suspect the multimeter, replace the multimeter batteries or get a second reading from another multimeter. With a voltage drop across the battery terminals to 8v the engine should not start because the EFI relays and ECM will not switch at much less than 9.5v.

Next I’d fully charge the battery to something greater than 12.6v. The formulae to fully charge a battery is
(battery Ah / charger A) + 10%
which means that to fully charge a flat 8.6 Ah battery will require:
2½ hours on a 4A car battery charger
9¾ hours on a 1A charger (Optimate 4)
11¾ hours on an 800mA charger (Optimate 3 or 2)
16 hours on a 600mA charger (Optimate 1)
32 hours on a 300mA charger (eBay/Amazon 'cheap as chips' special)

Once fully charged discharge the surface voltage by switching the ignition on for a minute or so and check that the battery’s level of charge doesn't drop below 12v and returns to 12.5 or greater when the ignition is switched off. Then load test the battery by applying full throttle (this disables the Fuel System) while cranking the engine on the starter motor for 5 seconds, expect a voltage drop to 10.5v, anything above 9.5v is acceptable, if the voltage drops below 9.5v then suspect a weak battery.

I’d doubt the spark plugs would be an issue, NGK specify their IMR8C-9H’s (stock spark plugs for the SC64) to have a 100,000 mile service life, although at 43,000 miles the motorcycles service history will be key. Apart from whatever stamps there maybe in the service book what do you know of the itemised service history?

If you’re allowed spanners and you haven't already, you may want to download the Honda Workshop and Owners Manuals here.

[Elskus]

Hi Art.

Some very useful info there.  will try a second multimeter to begin with.
I have a 4 amp car charger, so will try that depending on the second reading results.

As for service history, it has been serviced every year and had new oil filters/oil change, air filters each time and the odd brake pads.  I think it has had a full fluid service a few years ago as well.
I have not seen any replacement spark plugs on any of the invoices

I have downloaded those manuals.  They look like they could come in very handy. 

Thanks, will let you know how it progresses

[Art]

Just bear in mind fast charging an 8.6 Ah battery on a 4A car charger is OK once in a while, for regular battery maintenance get yourself a motorcycle specific battery charger. Reduce the charging time with a 4A charger according to the batteries level of charge to eliminate the risk of cooking the battery, 1 to 1½ hours should be safer.