Jim's freebie Winter Hack, Work has commenced!

The carbs are a replacement set that came with the bike cos the others were displaying probs alread so the guy bought a second set (he knows less than me). I had this second set professionally cleaned by V-Twin customs in Rye. They found a dodgy diaphragm which I replaced, a broken vacum cap and a crack in the plastic top, all this was rectified by me I then took the originals off and put these on.
All the moving parts of the carb ie choke etc are working fine. No I didn't need choke to start which is suprising cos GSs tend to be bitches to start at the best of times, it runs better at cold, as it warms it gets worse so I played with the adjuster but this just made the revs wiz up and down, as it got warmer it started to rev up on it's own slightly then died down and unless I blipped the throttle a bit it cut out completely. Now warm it wouldn't start at all and then the battery which is fcuked wont start it at all.

The plugs definately look like the top picture the LH one dry but BLACK and the RH one WET and Black smelling of petrol!
Does that help?

 

I'd suspect you're getting to much fuel in, a crap load too much in fact.
When cold the extra fuel is acting like the choke (sort of anyway, a choke actually creates a low pressure 'bubble' inside the carb pulling fuel in at a faster rate to compensate for the slow vaporisation of the fuel when cold. (Like you cared)) but as the engine warms it's just flooding it.

Balancing carbs isn't the same as setting the correct mix, balancing is just that - making (all) the carbs run evenly but observing the pressure drop in each carb, meaning they will all suck an equal amount of fuel.
What you can try (for funzies) is winding back the idle mixture screw a bit, see RW's link pic 4. 1 screw per body. Adjust it same as you would suspension (again, like you care.) wind it in until it stops, counting how many turns and make a note. To lean up the mix you 'should' (and that's only based on most carbs) have to wind the screw out a little further:
So, wind screw in till stop and count (say 4 for example.) make note, then wind out the same amount +1. Do that to the other carb too.
Try running.
Bit better? Wind again and try. Repeat.

If you find you are able to get her running steady then tweak the screw back in until you are at the minimal amount needed for it and pop along to a tuners to get the mix checked so you aren't running lean.

Should keep you busy a while, i'm going to make lunch

 

Thats brill and gives me something positive to do! You must stop assuming I care so little, I care very much and bow down to your superior knowledge all of which I am in awe of

Seriously though matey it's having people like you to 'tap' into that makes this site so worthwhile, that and your sense of humour! If your advice works I owe you a

 

Who are you kidding, you owe me that anyway. If it works you owe me 2

 

Just one thought. Just because the plugs are new doesn't mean they are working. Some defective plugs miss more the hotter they get. Once one gets hot and sparks irregularly it will get black, and will then get wet. Try swapping the plugs around and see if the problem moves with them, or put one of the old plus back in.

 

AHA! Another one worth a try!

 

OK so I stripped the bike down again got the carbs off adjusted the mix screws in the carb bodys, wound 'em all the way in, they went 5 times so I wound 'em out 6 as per Scortchio's advice and put it all back together,......................Yup you guessed it tickover sweet as a nut for about 3 mins then same old same old, rev it a little it cuts out and wont start till it's cooled off a bit. Starts but you have to keep fettling the throttle to keep it running and if you let go of the throttle it cuts out. . Thought it was fixed at first when it was running well, do I take em off and wind them out 7 turns?

 

On the plus side, the new luggage rack looks good sprayed up and I've got a nice little belly pan to fit! Anyone want to buy some engine crash bars for a GS 500E?

 

Sounds like it's running way too rich or the plugs are borked, as JimG suggested. if you've swapped plugs and it's no different then starve off the fuel a couple more turns, see if it helps. Go for 8 or 9 just for giggles, a larger change will be easier to notice.

You have made sure the vacum lines are clear and connected, right?

 

EH? vacum lines errr? Dunno, where are they? Theres two vacum take off pipes that are blanked off with caps that are there for when you balance it, as I understand it anyway.

 

Just make sure they're from the same model.

That looks like a v early GS500 to me, the one that produced a genuine 50+ hp and had a top speed nudging 120. I had one in 1990 till about 97! Later models (identifiable by higher risers on the clip-ons and a different exhaust part number (it's got a noise-reducing 'bung' in it) also had different carb internals AFAIK.

 

Running rich - have you checked that the choke is fully returning? It's cable operated, and liable to seize up... I also seem to remember that if you pop the tank back on a bit awkwardly you can damage the slidy thing that the cable pulls.

 

The replacement carbs match the the originals, I know this because I've had 'em all apart. The choke and all the moving parts are working fine as I greased and lubed everything before putting it back, I'm a bit anal when it comes to stuff like that. Thanks for the contribution though Kev, all helps to problem find.

 

This might be a silly question Jim, but are the carbs drawing the fuel from the fuel tank or elsewhere ? If they are drawing fuel from the fuel tank, I believe you need to attach your vacuum line to the petcock in order to maintain fuel flow to the carb (the vacuum to the petcock is like an auto shut off, so if your engine isn't running fuel doesn't continually leak out). If you rev your engine it will draw the remainder fuel out of the line and with no fuel coming in at a decent rate it will die.

I think leaving for a while may allow fuel to slowly fill the line up, hence allowing you to start her up again.

Just another trouble shooting angle. This is on the assumtpion that your bike does have a vacuum petcock....looks like a silverish flying saucer...

/edit possible the vacuum bit could also be built into the on/off/reserve petcock and if the diaphragm is faulty in there could cause fuel starvation. If you can bypass the petcock completely you could determine if that is the problem.

disclaimer..I don't know anything...

 

OH GAWD, 20 yrs of motorcycling and I have no idea what a petcock is?

 

Pet(rol) cock... or tap

It is possible to connect the hoses incorrectly. Don't ask how I know

 

If only you knew how many things I've actually accidently set light to, myself included!

 

Petrol Tap! AHA, phew glad I do know wtf we're talking about now. No pretty sure all the pipes down there are connected up ok, thanks though.