2001 SV650 that wont stay running

I am new to the board, so thanks for taking the time to read this. I am at wits end. I searched the forum for "bike wont stay running" and got no real relevant results.

That said, here we go:

I have a 2001 sv650. As far as I know it is all stock. Beginning of last years riding season when I went to take the bike out, it could not run on anything but full choke. Knowing something was wrong, i pulled it all apart to find a nasty green color and crystals (from letting the fuel sit in the bowls for too long and or the gas stabilizer I added the previous season end). My brother and I took the carbs off and cleaned them up with carb cleaner. Made sure the jets were clear and put them all back together. Fired up the bike and all was well. As the riding season progressed, I noticed some popping in the exhaust if I idled too long (I know, why is it runnign and not moving. I talk a lot). I put it away for the winter in a garage, (this time with no Stabil in it). Spring rolled around and it fired right up. Little bit of popping when idling when I first start it up, but after getting up to speed and driving around, it seemed to clear out.

A month or so ago, I noticed one of my cylinders seemed to not be firing. Rev it up and it came back. All is well. about two weeks ago, I went to take the bike for a ride. Fired up no problem. Had the choke on, and it was idling for few minutes so I knocked the choke off. Pulled it out to the street and started to finish putting my riding gear on and the bike's rpm lowered and then it stalled. I tried to restart and no luck. Keeps stalling. I took the carbs back off and got new jets, and needles rebuilt put back on. Same thing. I can start it, it runs for a few seconds and stalls.

I seem to be getting spark to the plugs (took them out and held them to the block while turning it over, looking for the arc in the plug gap). I had the air cleaner both on and off, same results.

It just doesn't not make sense to me and I am not sure where to look now. Any insight would be appreciated.

thanks,
Allen

[fizzwheel]

You could try draining all the fuel out of the tank and carb bowls and replacing with fresh fuel.

I dont know about the USA, but here in the UK our unleaded petrol goes off over time and I've had problems starting a bike with stale fuel in it.

Failing that my other thing to check would be the choke plungers on your carbs, make sure they are not stuck and that the choke is working properly.

I had similar symptoms to yours when my choke was stuck and wouldnt work.

Not sure what else to suggest, hope you get it sorted.

[Biker Biggles]

Fuel starvation?Is there any fuel getting to the carbs?Air leak.Is there air getting in around the inlet rubbers or where the airbox sits on the carbs?Water in fuel.As fizz says drain it all out and start again.

Thanks, I will look into the air leaks.

How can I tell of fuel is making it in? When I took the carbs off, the bowls were full. I am wondering if the passages are clogged from the bowl to wherever it shows up in the venturi.

I have turned it over with the airbox off, I noticed the black pieces (plungers?) were not moving with our without the choke engaged. Should I see gas spurting when I look in there?

I found that in leaving the gas line un-attached, my gas excited the tank even though I thought the vacuum cutoff switch would stop that. Bad thinking. The shed really stunk after that. But I have new gas now.

I have added some fuel system cleaner to the gas hoping that my find any scaling and eat it way...

[fizzwheel]

Originally Posted by Farmer-al

I found that in leaving the gas line un-attached, my gas excited the tank even though I thought the vacuum cutoff switch would stop that.

It shouldnt do that, something not right with your fuel tap. It should only let fuel through it with the engine running. I suspect it might have some gunk in there and the tap's stuck open or its just knackered.

I can't remember if you can take it apart to see or not, I didnt in the end I bought a new one.

If the fuel is draining out of the tank into your carbs with the engine off it might attribute to the poor running you have.

Also if it is it might be draining down into the sump and contaminating the oil as well. ( I had this problem to )

When you take the airbox off is there any liquid / oil / petrol floating about in the bottom of it ?

Examine your spark plugs and check the colour against what they should look like with correct mix. If I remember correctly too lean a mix will give a whitish colour. Too rich makes the plug sooty.

ejohnh-> I just replaced the plugs. The old ones were blackend, but I did not feel excessively nor did they have texture (like carbon build up).

Fizzwheel-> I did not notice any liquid in the airbox. I will look again just to be sure. I bet the fuel valve is busted. It doesn't gush, it must have dribbled. But I will double check to make sure.

Check that the choke plunger is returning OK. May be stuck on choked? Is there any resistance when you put choke on? oops! I think you mentioned that you checked that before.

[fizzwheel]

Originally Posted by Farmer-al

Fizzwheel-> I did not notice any liquid in the airbox. I will look again just to be sure. I bet the fuel valve is busted. It doesn't gush, it must have dribbled. But I will double check to make sure.

OK that sounds like it might just be excess petrol in the pipe. When my fuel tap was stuck open, when I removed the pipe it literally gushed out and the fuel went everywhere till I stuck my finger over the pipe.

ejohnh-> I was suspecting the choke the first day, when it stalled on me. no with it not starting, I am thinking it is something else.

I moved the plungers by hand so I know that is OK. the only think that could be weird is if there is no vacuum to pull them back (Not sure how to test this) as if a passage is blocked...

When I reassembled the carbs and re-routed the cable (instead of removing the cables from the carbs), the cable did not seem to be as long, not nearly as much free cable to attach it to the choke lever, but I thought maybe it was my imagination because I did not pay too much attention when I disassembled it. I checked that everything 'in the rubber boot' was set in OK and it seems to be. I checked all the cables and they seem to move freely...