Curvy won't idle reliably, cuts out.

RAC saved the day, temporarily.
This happened once before but the bike recovered and i never thought owt else of it. what do you think? this is whats happening...

When pulling up at lights the bike dropped to 1k rpm and then continues to drop and cut out unless i catch it with some revs. - even if i do catch it with revs and hold it, when i set off the bike seems to choke and cuts out.

first time this happened i couldn't get it started at all, waited 10-15 mins, and wheeled it to the local bike shop where it magically started and acted like normal, they were just as baffled as me. - took it back to where i bought it and questioned the strange behaviour which i was told was down to "moisture in the engine, and once its gone it runs normally". this i took with a pinch of salt, but still it didnt happen again until now. about 2 weeks after the first incident.

wouldnt start at all again, sick n pee'd off i called out RAC - opened the bike up and found that when disconnecting the wire from the rear cyl. spark plug there is no drop in engine idle speed - he believes this cyl. is faulty in one way or another, and that it also appeared no fuel was getting to it, he blasted the jets, and the bike ran ok for 2 or 3 mins but still getting alot of mis-firing/popping. anyway it was enough to get me home.

can anyone confirm or otherwise add to this so i can explain myself clearly to the garage in the morning please?

The bike is still under warranty so i want this **** fixing up properly.

[DJ123]

what bike and year is it?

sorry, was just about to edit my post adding that!

1999 SV650S

I had exactly the same thing on a K3 SV ......... went and checked all sorts , bought new plugs for it and it was fine . The tips of the plugs were fine but the cores themselves were not probably functioning . New set and bango .... all was well

so new plugs are the answer. amazing, thanks! it'll stop all the popping misfiring too?

My Service book recons it had some iridium plugs in only 1000 miles ago, is that normal life for sparks plugs?!

http://forums.sv650.org/showthread.php?t=128642

Have a mooch in there and see if it sounds familiar

It might NOT be the answer , but a bit of detective work will narrow it down

Cheers Badger, much appreciated - i'll get reading!

[Dave20046]

Originally Posted by phatwheels

so new plugs are the answer. amazing, thanks! it'll stop all the popping misfiring too?

My Service book recons it had some iridium plugs in only 1000 miles ago, is that normal life for sparks plugs?!

To be fair I'd change the plugs straight away if it's an option, plugs will last 3000-6000 and beyond and there's no need for iridiums in the SV. You can always keep the old ones as spares/to put in next service if you rule them out.

I had a similar sounding problem with my curvy, when the choke plungers were seized. The issue raised it's head when the bike was warm, but I think you'd notice it a bit more consistantly if they were properly seized.

If you're changing the plugs I'd check the plungers and possibly clean the carbs as a matter of course while you're down there if it's an option.

Then again I'm just speculating based on experience, I'm no mechanic - you might want to wait for someone else to come along especially if the bike's your only form of transport.

The cylinder being 'faulty' sounds like flashing amber light man bull****, but could be wrong.

Where'd you buy it from out of interest?

[Sid Squid]

When it idles correctly and doesn't die, at what speed does it run?

When it won't restart what technique are you using?

Thanks Dave - Bought from SMC mid April, yeh only transport for me. will drop off at SMC tomorrow.

Sid - when it idles ok its 1400rpm there abouts. When it dies and wont restart, i try with a little throttle and sometimes get nothing at all, other times it just turns over but never fires up, and if im lucky it'll fire reach 1000rpm then cut out if i don't catch it, but catch it n rev it n its sounds horrible.