my bike has trouble starting up after rain sometimes

I noticed my bike sometimes has trouble starting up if it has rained the night before or if it's been raining all day. This bike resides outside all year round but I have a bike cover for it. Example for today it took my entire battery and then a jump start for it to finally backfire and then turn on. (It backfire because I was trying to start it while playing with the throttle which really helps to turn on for me sometimes) it wasn't a matter of low battery as I've already ruled out because even when I have the jumper attached it takes quite a long time for it to actually still turn on even at full engine starter power. Could it be that moisture is getting into the engine starter area perhaps or the spark plugs? Where is the starter located anyway? I know where the spark plugs are. Any inside on why this might be happening?

My initial guess would be moisture on the plug wires. You could try spritzing the wires & plug caps with WD-40 AFTER they are throughly dry. And spritz the coil too. If that isn’t successful then replace those wires and caps with the correct items sourced from Honda. Maybe you’ll even have to replace the coil.

Further to that, if you were to remove the tunnel cover and try to start the engine under those wet conditions you may very well see arcing from the plug wires.

Meanwhile the next time you start the bike under those wet conditions try starting the bike with the throttle cranked wide open. IIRC there is something in the ECM which alters the ignition, timing or something under WOT which aids in hard starting situations. I know that’s the go-to procedure for starting “flooded” (Honda) engines.

Please let us know how you get on with this. We all benefit from shared information.

Sounds like its time for a little TLC.
Are you running on E10 fuel, E5 or plain unleaded?
Does it smell of fuel when you try to start?
Are the plugs wet or dry after a failed start?

The plugs are accessible by removing the cover under the front of the seat, you will need to raise the seat to remove a screw each side then lower the seat to remove the panel.
the plugs are well protected so moisture is unlikely but remove and check for a spark and colour, should be a sandy brown. Would be a good idea to replace the plugs with Iridium NGK CR8EHIX-9
if not already fitted.
Apart from that it's down to checking wiring connections(sockets/relays) from the coil to ignition switch.

To find the starter you will need to remove the seat and plastic cover that holds your tool kit on the top of the engine. Then remove the big black airbox to expose the starter.
A known issue is the starter relay carbons up giving reduced grunt/amperage/volts, contact cleaner is your friend there. Same for the start button on your right hand switch cluster

Hope this helps you find the problem.

Keep us updated or shout for further help.


Be safe, be seen!

Cosmic_Jumper wrote:

My initial guess would be moisture on the plug wires. You could try spritzing the wires & plug caps with WD-40 AFTER they are throughly dry. And spritz the coil too. If that isn’t successful then replace those wires and caps with the correct items sourced from Honda. Maybe you’ll even have to replace the coil.

Further to that, if you were to remove the tunnel cover and try to start the engine under those wet conditions you may very well see arcing from the plug wires.

Meanwhile the next time you start the bike under those wet conditions try starting the bike with the throttle cranked wide open. IIRC there is something in the ECM which alters the ignition, timing or something under WOT which aids in hard starting situations. I know that’s the go-to procedure for starting “flooded” (Honda) engines.

Please let us know how you get on with this. We all benefit from shared information.

Where exactly am I spraying dw40 on the sparks?
I have the original toolkit that came with the swing but I don't know how to use the included spark plug remover tool to actually remove the spark plugs. It looks like it needs something else

JohnyC wrote:

Sounds like its time for a little TLC.
Are you running on E10 fuel, E5 or plain unleaded?
Does it smell of fuel when you try to start?
Are the plugs wet or dry after a failed start?

The plugs are accessible by removing the cover under the front of the seat, you will need to raise the seat to remove a screw each side then lower the seat to remove the panel.
the plugs are well protected so moisture is unlikely but remove and check for a spark and colour, should be a sandy brown. Would be a good idea to replace the plugs with Iridium NGK CR8EHIX-9
if not already fitted.
Apart from that it's down to checking wiring connections(sockets/relays) from the coil to ignition switch.

To find the starter you will need to remove the seat and plastic cover that holds your tool kit on the top of the engine. Then remove the big black airbox to expose the starter.
A known issue is the starter relay carbons up giving reduced grunt/amperage/volts, contact cleaner is your friend there. Same for the start button on your right hand switch cluster

Hope this helps you find the problem.

Keep us updated or shout for further help.


Be safe, be seen!

I use 95 (plus) fuel on it.
Only starts to smell like fuel when I crank it while trying to start it up with wet conditions. I definitely have to replace the spark plugs as I've reached 20,000 miles already but I don't quite know how to use the included spark plug remover tool to actually get them out

Here's a vid on how to check your plugs, the person uses a conventional plug socket and ratchet bar but you can use the bike tool. Insert the tool firmly down onto the plug then you will need a 10mm socket and wrench or the 10mm spanner in the tool kit to loosen the plug and draw out.

https://www.youtube.com/watch?v=ij5nc5-Peaw

I hope this helps you.

Be safe, be seen!