Cold weather issues

Sup guys, I’ve lurked this forum for a while now and am a big fan of the SV650! I’m currently on my 2nd one, a 2005 650s, but I seem to be having some problems with it. I’m hoping/pretty much begging for some Sherlock to take up this case and help diagnose what the hell is going on with my bike, and why it keeps stalling/lugging in the cold.

Today was a cold day, fired up the bike fine – it always starts on the button from cold. However as the fast idle drops speed the bike sometimes drops the revs lower than it should, about 1000rpm. This only ever happens in the cold/after a wet ride and usually the bike idles fine around 1300rpm. When it’s lugging a bit low if I give it a bit of throttle then close it usually returns to a normal idle. When warm there is no problem with the idle.

However, here comes the really annoying bit. From stationary/idle when I go to open the throttle, even just 1%, the revs first drop from ~1300rpm to 900-1000rpm. Usually a bit more throttle will bring them back up as normal but the overcompensation means they shoot up. In riding terms this means when I go to pull away from stationary the bike has almost no power when I initially open the throttle, then suddenly shoots away as the revs kick in.

On the other hand sometimes the revs drop so low with 1% throttle the engine stalls and usually won’t start again unless I give it some throttle and keep the revs artificially high by keeping the throttle open. If I try riding it like this the revs surge up and down even when keeping the throttle steady, possibly due to 1 cylinder dropping in and out. The bike won’t even idle at this stage, it just stalls and the more times this happens the harder it is to start again. I believe at this stage the engine is flooded as the red light comes on, sometimes I can get it to start and idle on 1 cylinder only.

I’ve also noticed that occasionally, even in ideal weather, the bike can stall by dropping revs as I come to a stop. This happened today as I approached some lights, I shifted down through the gears, hit 1st, gently applied the brakes and pulled the clutch in. As the bike slowed and the clutch came in, the revs dipped, the bike stalled and I had to start it with throttle and keep it open until I could pull over.

Here http://www.youtube.com/watch?v=w7bLQ...ature=youtu.be is a video demonstrating the above problems with revs dipping as I’m pulled over off the road. I was trying to get the bike to stall like it normally does when you blip it, but the stubborn ****er wouldn’t play ball. I can re-create this effect sometimes in normal weather if I ride at speed, pull the clutch in, close the throttle and roll. The revs dip low to stalling point, similar to this thread (http://forums.sv650.org/showthread.p...highlight=cold).

The bike has pretty much been fine since last winter when the same problems were happening. I took it to a garage who changed the spark plugs and inspected it. They couldn’t find anything wrong but changing the plugs didn’t fix it and apparently it ran no error codes. After burning my money I demonstrated the problem and they were stumped.

Is there something wrong with the fuel delivery, I'm not very mechanically mined? I would be extremely grateful for some help!

I would check the TPS(throttle position sensor), i've had simillar happen on cars and motorbikes and its worth checking at least. It basically converts the mechanical throttle movement into an electrical reading for the ecu. I found this thread which shows how to check it.

http://forums.sv650.org/showthread.php?t=55459

[Red ones]

Just sorted the same problem on mine.

I got the throttle bodies balanced. It isn't a hard task, but I don't have a set of vacuum gauges, and as they cost about £80 I took it to the garage. They charged me £45 and the bike is well sorted.

I would check the TPS afterwards, that's easy enough and well detailed on this site as Urbanfireblade linked.

Cheers guys, I'll probably just ask the local garage to sort it all out. Don't fancy fiddling around with my bike on the street in the dark and cold! Red ones, was it the very same problem do you think? I would love for this to go away so I can start trusting my bike again!