Stalling weirdness

[CheifWiggam]

I've seen a few others report similar issues with engine stopping events and all seem to point to plugs and/or carb balancing and unsure if my issues is the same.

For about 3mths now, cruising along suburbia (60kph) with a neutral accelerator the engine can cut out momentarily (by the time I look down at dash, it's back - that quick (hard to tell if electronics cut out or fuel)). I thought maybe fuel filter but as mechanic pointed out - it's a gravity system and would expect to see that behavior under load (note: it still pulls like a 18 year old)

So, I get it serviced by local ol' school mechanic Paul Illingworth, new plugs, new fluids and carbs balanced. Whilst I now rarely get the engine dropping out if I sit at the lights for a minute or so, at idle, the engine just stops. No discernible change in idol note, tacho barely moves, idle is probably on the low side at 1100rpm. - then kapoot!. I was able to re-produce this morning so hoping to try and repeat this afternoon.

If anyone has valid suggestions about how best to problem solve this - I am all ears! Don't know if the initial cut out is related to the newer stall issue or how I can best test to give me a direction before pulling it apart.

PS> Im aware of both the idle/ohm and R/R 'things' but was hoping to crowd source a general direction

[alanfjones1411]

Sounds like carb farts.Turn idle up 1200/1300 rpm.It's a firestorm thing.Hopefully that'll cure the at lights etc.

[MacV2]

Yep first thing is turn the idle up a tad.

There was a Honda recall on these to prevent stalling on heavy braking... Pull the tank & air box off. Look at the carbs, nestled inbetween the carbs are two pipes held together by a thick black (approx 10mm wide) rubber band. They are a breather for the carbs or something... Pull them out & let then hang down beside each carb.

[CheifWiggam]

Turning the idle up to 3K worked a treat and meant I could just roll off the clutch to start but started hampering the tank range - dropped it back to 1300 and it appears to have eliminated the glitches.

Now to figure out why the LED brake light only works when globe plugged in to unused socket, thx all.

[VTRDark]

If you want it to idle at 1100 you will need a very well tunned engine especialy the low speed idle circuit and fuel mixture. You should be able to drop your idle down to around 600 without it stalling at idle. That does not mean you should run it that low and the manual says it should be at 1200, I tend to run mine just above a 1000. I would reccomend no lower than 1200.

You say it cuts out momentarily, so does not fully stall then. Battery connection would be my first port of call and check that the connections are secure. The next thing would be plugs but you have changed them so the next thing up the ladder is HT leads, first make sure that they are securly fitted especially the front as they do require a rather firm push onto the plug so they clip on securly. You can feel when it's seated fully as there is a very noticible click. Then the coils but don't just go swapping them out for new / used ones. Make sure the electrical connections are good. As this is an intermittent fault it's crying out electrical loose / faulty connection somewhere.

My gut feelling is saying to adjust the TPS and if the engine was fully stalling for no apparent reason then I would have said that straight away, but from what you describe it's intermittently cutting out and then back in. It would help if you could determine if both cylinders are cutting out or is it just one so not really cutting out but more of a stumble. It might be a tricky one to track down this. Lets hope it's something as silly as a loose battery terminal. You might as well check the engine earth while you at it. And stick the idle speed at around 1200 - 1300 and monitor how things go. Sometims we have to let a problem grow and show it's true face to determine where an issue is. Let the engine give us some more clues.

[sirch345]

I would say the same as Carl as for adjusting the TPS. You mention it in your original post, but I'm not sure if that means you have already adjusted it, or checked it

Chris.

[grumpyfrog]

Id check your battery connection to start with, as mentioned. Ive sufferd this with another bike previously. All looked fine, but connection was not screwed tighlty enough. And yes, was only when you were "not on it" did it cut and fart around.

[CheifWiggam]

Thx for the "where to look" directions all,
I've got a weekend workshop setup to upgrade the brakes in the coming weeks so whilst I'm there, I'll double check the electrickery.

I've had the fuel tank opened but CBF actually removing it, any "gotchas" to look out for when removing?

[Wicky]

Take photos for reference of where all the fuel, drain and vacuum hoses connect to before disconnecting - and mind the fuel level sensor cable & connector which plugs in nr the battery. Plus the fuel tap flap can be a head scratcher to put back correctly the first couple of times.

[AMCQ46]

Make sure it is close to empty, having 10 to 16kg of liquid sloshing about when you are trying to hold it up to remove or refit the pipes makes it much harder, especially if you don’t have a helper.

[Wicky]

Also a HRC tank prop stand cut to the right length helps...

[Twitchy]

Not sure if I'm barking up the wrong tree, but I used to have clunk/die and cut out issues when stopped at the lights or idling too long. Incidentally the Idle Drop Procedure never worked for me. Dropped pilot jet down 1 size, now I rarely get clunk/die/fart thing, and the Idle Drop Procedure works!