Hi all,

In need of some assistance. Bike is a FUEL INJECTED Honda CBR600f, 2001 banana seat model. Just to set the scene:

Hadn't ridden the bike in about 2 weeks (jury service), then rode it friday - it started and ran fine but my left indicator had been playing up. I was also very low on fuel, it wasn't chugging or stopping etc, just low.

Sunday, I decided to sort the indicators out. I changed a bulb which was corroded and opened up the left hand switchgear to find a small amount of thick, dry grease. Cleaned this out with contact cleaner and applied liberal amounts of lithium grease. The grease was thick and not really going where I wanted it to so I thinned it with a quick spray of WD40 and then worked it into the switch. Whilst I had the WD40 out I sprayed it into a few connectors just to drive out any water (I commute on it), this included the indicator plugs and the back of the harness leading to the ECU (only a tiny spray on the ECU wires). Indicators now work fine so I put it back together and tested everything (lights, horn, indicators, bike starts etc) before putting it away. Engine started fine and I rode it 10ft to the garage before locking it up...


The problem:

Come monday morning - it turns over and over but it wont actually start. I was low on fuel last week and concerned the battery was flat (although it ran Sunday and Friday) so I charged it up and added a jerry can of fuel. Still nothing happened aside from turning over continually.

I can hear the fuel pump prime when I turn the ignition on, killswitch is on or it wouldn't turn over...

Only thing I can think of that is associated with the bike starting that I may have interfered with is the clutch switch which runs from the clutch lever to the left hand switchgear then onto the rest of the bike. I tried shorting the two clutch switch terminals but it didn't help. Would thinned lithium grease settling into the wiring of the clutch switch interfere with starting? Seems a bit unlikely considering the role of the clutch switch.


Seems far too coincidental to rule out me breaking something, all it has done since yesterday when it started and today when it wont is sit in a garage. Tried starting it in neutral with and without the sidestand up and in gear with/without clutch pulled etc. No difference.

I did check the clutch switch fuse, not blown. Also getting concerned that WD40 into the ECU wiring has ****ed it even though displacing water in electrical connections is exactly what it was designed for.

Any suggestions please guys?

Cheers

 

eeehh Donny, WD-40 on electronics is a giant nono. WD40 is made with mineral oil and can ruin certain plastics and definitely not good for sensitive electronics. Yea, it displaces water, but keep far far away from electronics.

There are specific sprays just for cleaning electronics and connectors. CRC makes some good stuff. if you wanted to protect electronics i would use Di-eletric grease (non conductive grease) or battery terminal sprays that build a film on connections to prevent corrosion. But even then i wouldnt use that on sensitive parts.

You bypass any clutch sensor issue by trying to start the bike in neutral. But i dont think this is your problem anyways.

I would repsray all of your WD40 areas with a heavy coat of Electronic Cleaner to get all that oil out of there. Check and recheck all your connections. good luck.

 

after you clean everything properly, and it still doesn't fire up. Try jump starting the bike; maybe the battery has gone bad.

 

okay after you clean everything with a quality electrical cleaner. make sure you let it dry before you put everything back together! i need you to do a few basic things.

1.Make sure your battery is fully charged. atleast over 12v dc.

2. pull a spark plug and check for spark by grounding the end of the plug on a good clean part of the frame free from paint. seeing as we know your most likly not have a fuel problem.

3. if you have spark check all your grounds and make sure they are clean and connected good.

4. by pass your Tip Over sensor, kickstand, and clutch safty switchs.

I had just had this problem with one of my f4I's it turned out to be my ecu. but lets start with the basics here. because i also had a bad stator, rectifer and anti-theft dieode.

 

Cheers for your thoughts guys.

It's not the switchgear, it wouldn't turn over when in gear and no clutch pulled. As such, I removed the ecu to find a small splash of WD40 sitting in the ECU plug. Removed this with electrical contact cleaner and let it dry out indoors.

Since then, I've had it start and idle ok, but when I go to rev it it dies. First, it idled rough and died as soon as I touched the throttle then wouldn't restart. A few hours of drying indoors later it started and idled ok, revved to about 4krpm before dying and not restarting. 10 mins after that it started well, idled ok and I managed to ride it about 30ft around my block keeping the revs very low. This was early in the morning and I didn't want to risk revving it hard and annoying people.

I am convinced that it will cut out when revved hard, but hoping that time "drying" out the ecu will solve it. WD40 in the ECU harness does seem to be the issue..

Problem is, here in the UK, the bike has an immobiliser which uses keys coded to the ECU. A new ECU means new keys, lockset, etc etc which costs an awful lot and is something I am trying hard to avoid.

 

sounds like you need to clean everything some more. Anyways, did you mess around with the vacuum hoses or the battery lately? if so, double check the connections.

 

SORTED!

As the ECU continued to dry out, it began to improve and this afternoon, ran 100%.

Just been out on a long night ride, completely back to normal.


So... WD40 and ECUs don't mix and the one purpose I thought WD40 did have, it doesn't.

Thanks for the advice :up: .

 

Nice!
WD40 is great for some things, but is horrible for others.

The word "lubricate" is not even on the can. But its on the their website!

I think it's best used as a solvent if anything, there are MUCH better alternatives for lubrication than WD40 such as silicone spray, dry teflon spray (my favorite!), moly grease, bearing grease, etc

Better alternatives for electronic cleaner too!