Engine cut out when warm

[JediGoat]

Had a bit of a twitchy-bottom moment yesterday on the way home from work.

My bike (K4) occasionally cuts out when completely cold and increasing the revs to pull away. In my book, that's kind of acceptable, and maybe even normal.

However, after riding for 20-25 minutes last night, I was between two cars at the front of a queue of traffic on the Euston Road. Lights go green, I go to pull away.....and puertwuuuwnik - the engine cuts out (that's the noise my brain understands it as ).

I immediately hit the start switch....and nothing. Try again...nothing. Add some throttle...nothing. Now cars are passing my (very closely) on both sides at increasing speed. It won't respond to just hitting the starter (same thing as when it cuts out cold), I get a veritable cornicopia of warning lights flashing on and off, and it almost sounds like there is no electrical power.

So I give it just a little throttle, and it kicks in....then dies. So I'm there with my hazards on....praying that no-one coming up behind is texting while driving!

After about 8-10 tries and half a minute of muscle-tensed panic (felt more like 20) I got it started and pulled away, and it was no bother after that.

So, to get to the point, does anyone else get this? Is it 'normal', or is there perhaps something foul afoot

The only other possibly relevant thing that springs to mind is that I was warming my left hand on the engine casing while waiting at the lights. I noticed (during the panic period) theat the engine temp was reading 100, but as I commute through central London, my bike can often get upto 104 without problems.

Any advice appreciated. If there's something I can do to sort this out, I would rather pay the money than gamble my life on London drivers paying attention.

Jo
P.s. On a positive note, I guess that contributed to the 'one scare a day' necessary to keep your heart healthy

I was going to suggest carb icing, but as I read on I realised this is unlikely. The bike shouldn’t really be getting to 100deg anyway, especially this time of year, is the fan working properly?

I’d be more concerned about that right now rather than the weird cutting out bit!! If the engine is getting that hot, it isn’t going too be too happy!!!

Check the coolant level in the rad, if you have gone to 100+deg before then you have probably spewed out some of the coolant into the expansion bottle, now theoretically it should suck it back when things cool, but to be honest, this doesn’t always happen (cap shuts, no return allowed). Obviously with less fluid in the system overheating is more likely etc etc …

If the fluid level has dropped, top it up with coolant mix. I have a curvy that doesn’t have a temp gauge, so I can’t say exactly what temp the fan kicks in, but most of my other bikes have kicked in around the 90deg mark. It might even say in the handbook what temp the fan is supposed to activate.

If the coolant is full and the fan is working properly then the temp (especially this time of year) should never go over say 95 deg. I’d say investigating this is your primary course of action!!

If fan and a levels check out then you might have a sticky thermostat?

my car (ford focus) did the very same thing the other morning, the engine was warm but every time i had to stop it just died on me after a few times and the car spending aday on the work carpark it was fine and has never done it since.
i just put it down to electrical gremlins.

[JediGoat]

Thanks for the advice Blue.

I'll check the coolant in the morning, after I've read the manual to see where the window is

I'm going to keep an eye of the temp reading next week. If it keeps reaching 100, then I'll call Rob at Berrington-Smith Motorbikes and get him to take a look.

It's possible that the problem is related to the fact that I binned the bike down the road about 4 months ago. It was a 15-20mph drop on the left hand side, but the lower fairing bashed the rediator a bit. The mechanic that did the repairs said the rad was dented, but still functioning fine.

I'll keep an eye on it. It may be was Kwak said - electronic gremlins having some fun!

Jo

What's your idle speed?


.

[JediGoat]

It was around 1500, until I had it serviced, then I've noticed it's nearer 1000

mines 1000rpm but i did my 4k service today and it says in the hand book adjust the idle to between 1200 & 1400rpm with the engine warm, had to turn mine up a tad.

[Scoobs]

I found 1400 rpm to be about optimal on the SV. 1200 was a bit lumpy. 1000 is just ridiculous. I reckon that's your problem right there.

I'm not sure if this will help but you could try the TPS adustment - Scroll down untill you get to the TPS for the K3.

Originally Posted by shop_addict

It was around 1500, until I had it serviced, then I've noticed it's nearer 1000

That's the problem (I would venture to suggest). When I had my SV serviced (haven't taken it back since) the numpty that did it brought the idle speed down to 1000 rpm and it kept cutting out on a closed throttle and made life pretty dangerous.

Just raise it to 1500 and you'll have solved the problem.


.