Stalls and pops

[Mark_h]

Hi, Newcomer to the site, so please forgive me if this has been answered hundreds of times before. I tried to search and turned up nothing.

I've got a 2001 K1. Runs a treat usually, but occasionally just dies. Goes from fine to dead. Pull the clutch, hit the starter and starts again instantly. Not on choke, not cold/damp/foggy, plenty of fuel. I've tried raising the tick-over to 1500 but still does it. Any ideas?

Also, I get a backfire from time to time. Usually if I've been using the engine to brake then pull in clutch and blip throttle, get a backfire but sounds more like coming from carbs rather than exhaust but could be mistaken.

Recently replaced airfilter, made no difference to either fault. Plugs look good, tried many brands of fuel including shell super dooper stuff.

Any pointers greatfully received.

[embee]

sounds rather like it's a bit too lean at idle.

If it was something like water in fuel/carbs I'd guess it'd be less likely to fire straight up again after stopping (though that could still be part of the problem).

I'd suggest first thing is to drain the carb float bowls to get any water/dirt out. It's not difficult if you are reasonably confident.

Lift tank (means first taking off rider's seat), take off airbox (clip on each carb entry, back one is easy, front one needs a looooong phillips screwdriver, and ease off the 2 breather pipes/clips.

Down between the carbs the 2 float bowl drain screws are hex socket allen screws more or less facing each other. They need only a turn or so slackening off and the fuel drains out of the bottom. Don't overtighten, just nip up. Easiest thing is to use old rag to soak up the drained fuel, virtually impossible to get anything in there to catch it otherwise. NO NAKED FLAMES!!!!!!!!!

See how that goes, if it's no real improvement, try a slight richening of idle mixture, say 1/8th turn out on the screws. They are very awkward to get to, easiest with airbox off to see what you're doing, but having done it a few times I've got the tools and knack sorted out to do it from below with the engine running, but very tricky to reach them.

Carbs do tend to accumulate crud over time, so it could be something and nothing if they haven't been drained in a long time.

At worst it could be the tank filler drain pipe rusted through letting water into the tank. :shock:

[Mark_h]

Embee,

thanks fo rthe comprehensive response.

Don't think its water in the tank as I've been having the problem on a fresh tank during a period of no rain. As for the float chambers would there be any other symptom of this? As apart from the stopping it seems to run perfectly. I would have thought that crap in the chambers would lead to problems at high revs as well as low but guess it's less inclined to suck it through at tick-over.

I'll give it a go the next time I get an excuse to take it to bits. Is there any other preventative bits I should be doing while I've got the airbox off?

The clutch cable seems a bit sticky on release once in a while but I guess thats just a bitch of a job regardless of whether the airbox is on or off.

Cheers,
Mark

[embee]

.....forgot to mention, I suppose you've checked the known wiring chafing points on the curvy models? :idea:

Behind both rider seat fixing bolts, the bolts are a touch too long and hit the harnesses behind.

Under the pillion seat, left side of the bike towards the rear, the harness goes round the edge of a frame bracket and can chafe through.

Any of these can give odd intermittent failures, cutting out, blowing fuses and whatnot. :?