650 k2 running very badly, not sure where to start!

[Schwaa]

Hi folks,nice place you've got here!

My first post and already I'm asking for help.

My sv650s k2 is not running at all well. She starts, but seemingly only on one cylinder with the other one occassionally managing to join in before spluttering out again. Ive made a little video with me ****ing about with choke and throttle to demonstrate what's going on:
https://youtu.be/emrfZEIfh5E

She's done 35k, been mine since 22k with hardly any trouble. I've been reasonably on it with servicing. A little while ago she started to cut out occasionally at traffic lights,etc when hot after a decent run. Gradually it started to happen more and more often but would always start again without too much trouble.

Then I didn't ride for a few weeks, left the bike uncovered (not unusual :oops: ). When I went to start,she eventually fired up but only on one cylinder. The other one tried to get going a couple of times but ended in coughing and spluttering and backfiring.

My first thought was to change the plugs,which was long overdue anyway. The front one was fully submerged under water and crap (as I was expecting, I've done my research :cool: ). This hasn't really made any difference (video above is with new plugs). Here is a picture of the old plugs if anyone skilled in the dark art of spark plug reading can tell me anything from them:
http://s27.postimg.org/5l87rb9f7/20150925_205406.jpg

I'm no mechanic but I'm skint, can't get the bike to a garage easily and I quite like learning from these things. I've been reasonably successful on the spanners with various other machines over the years. But I'm not sure where to go from here. I've read around quite a lot and searched the forums which has lead me to a list of possibles but any advice or pointers from you guys would be massively appreciated.

List of possibles, maybe?:
Coil/ht leads (although plugs appear to be sparking well)
stuck choke plunger
Blocked jets
Other carburettor problem
Cam chain tensioner / timing (definitely a bit clattery, esp when other cylinder is cutting in and out)
Stuck valve

Also,how can I tell which cylinder is misbehaving?both pipes are getting hot. Do I need a vacuum gauge?

Any help would be great,even if it's just to tell me I've got it all wrong.

Cheers,
Josh

[maviczap]

Start with the choke plungers, those plugs look very black, should be a light brown colour

Front looks worse, which is the usual culprit

Blocked jets wouldn't give those symptoms

Not cam chain or timing, carbs could be out of balance, giving the clattery sound

If sparking well, then prob not coil or HT leads, but maybe once it gets hot.

If the front plug was under water, then spray the cap with WD40 and see if that improves things, maybe a new plug cap might help. But fit a fender extenda, as it doesn't do the front plug any good

[Biker Biggles]

As above,and look into possibility of water in the fuel.Does the drain pipe from the filler cap area work properly?Also check the crankcase breather pipes.There are two of them.

[Schwaa]

Thanks guys, gonna get stuck in tomorrow, I'll let you know how it goes...

[maviczap]

As above,and look into possibility of water in the fuel.Does the drain pipe from the filler cap area work properly?Also check the crankcase breather pipes.There are two of them.

Aye good point, make sure the drain pipe that runs through the tank hasn't rusted through and allowing water to get into the fuel tank.

[nutzboutbikes]

If its running on one cylinder and the other one is intermittent I would be looking at the ignition system, try taking the leads off and snip a few mm off each end and refit.

[punyXpress]

Which plug is misfiring?
2 second job to check - spit on the front pipe.
Where did the water & carp go when you took the front plug out?
Clean the front plug drain hole out - a pipe cleaner will do, then give it an occasional shot of WD40
Have you checked that the choke 'divider' is not sticking?
That's your homework for the weekend

[Schwaa]

Thanks for all your great help,gave me the confidence I needed to get on with it.

Started by draining the tank (less than a gallon so pretty painless) and float bowls. There was a terrifying amount of water in there! A gallon of new fuel and she's running okay now. The tank drain pipe was blocked with crap right at the top. I cleared it and I'm hoping for the best. Despite the amount of water in the tank, i didn't spot a speck of rust in the mixture I drained out. Guess I'll find out when I go to fill her up!

I've only had one previous experience of water in a fuel system, on a big old marine diesel 2 pot. It was really bad news because of the huge compression involved with those things and the uncompressable nature of water. Are there any problems that might need addressing as a result of trying to run my sv on rain water? Possible damage to pistons/rings etc?

Gonna run a fuel system cleaner additive anyway and try and get hold of a set of vacuum gauges. It's still sounding a bit lumpy but I don't really want to do anything major as I need the bike as transport rather than a project! I know at some point I need to get in to do valves though��