1982 GS550 dies at idle

[Anonymous]

Hope you guys can help. I have a 1982 GS 500 MZ Katana that I bought off a mate for $100AUD and spent a pleasant 6 months putting back together in such a way that it will actually work, you know spent 1 long week tracing those burning out fuses to a bodge wiring job deep in the loom! Anyway finally got it all together, properly wired, fuel tank clean, fuel filter fitted, new cables, brakes serviced etc. and its running not bad for a 22 year old bike, small hole in exhaust at a rivet in the muffler, makes noises a runs, even takes two-up with the missus. Anyway to the problem...took the bike for a 50km run to the Australia day fireworks at 9pm at night, runs fine all the way into the city, we park up watch the fireworks then start the run home at about 10-10.30pm. Bike starts first push of the starter button, we get on and start to filter smuggly-like between the jammed solid rows of cars (suckers!!). Anyway we come to a bit where the car drivers in their wisdom had jammed soild with about 7 different vehicles in different directions - no room to weave between them so I had to sit and wait it out, after 2 or 3 minutes just sitting on neutral and at idle the engine just dies. No amount of sweating, pummeling the fuel tank and pressing the starter button will evoke any king of internal combustion in the cylinders, just the noise of the starter motor turning the engine over without catching...I'm now starting to feel alot less smug! as the cars then start to filter past me again. I leave the bike for about 5 minutes, try again and whoom starts first press of the starter button. Runs again but next time I'm sitting in idle it does it again, again I have to wait 3-5mins before it starts - once we got moving though through the traffic it ran fine all the 50km home again. Is this an air lock, or flooding? what could cause this? anyone else experienced it and what can I do about it ?(in the words of Willard Whyte...Diamonds are Forever).
It did this once before on a cool morning (cool mornings in Australia in about 7-10 celcius not any of that ball numbing freezing crap you guys get in the US!), repeated presses of the starter did nothing, and only later when the air and bike warmed up in the sun did it go...any clues there?

[saaz]

7-10 at night...must be Melbourne!

Hi from Canberra

If the bike plays up after running awhile, most likely and easiest to fix problem is the air vent hole in the fuel cap. The bike may be creating a vacuum in the tank the longer it runs, but the vacuum dissipates when left a while. Try cleaning out the vent hole in the fuel cap. If the bike stops again, try opening and closing the tank cap, and see if that works. If it does, a vent blokage is the culprit.

[AOD]

you really need to figure out if its dying because of fuel or spark loss. a good indicator would be to pull a spark plug boot when it dies, put another plug in, ground it to the block, and look for spark. if you have spark, its a fuel issue.

if its a fuel issue a good check is to make sure the petcock is working. i'm trying to think of a good way to test it...so i'd say put a vaccume on the petcock vaccume line, and leave it in the RUN position with a hose going to a fuel canister. keep the vaccume on it, and see if the petcock continually lets fuel flow. i've heard of guys having it only work for a fuel seconds.

if its a spark issue...i might lean towards the coils. i had a coil on my first 550 that didn't like sitting in traffic. it would get hot, and spark 1/5 times it should until i got moving and it could cool off.

~Adam

[first timer]

the gas tank maybe vacum locking to, the filler cap needs to breath to let air replace the used fuel. i would take aprt the filler cap and clean it. see if that helps. if it happens agian try removing the gas cap and see if that helps, you could also install a clear fuel filter and if the bike dies agian look at the filter to see if it has fuel in it, you may ahave a bad petcock.

ryan

[Anonymous]

dies at idle

I also think the problem lies in the fuel cap.According to the Scottish tourist brochures I live in a tropical country,but the truth is we can have every element of weather known to man,rain,sleet,snow,sun changing every fifteen minutes.I dont know why but this does exactly the same to my 82 Suzuki GS550LT.The solution has always been to take the fuel cap off and simply put it back on again,once or twice I had to blow in the tank?.again I don`t know how this works but I always get home.It might be an easy fix,before you start pulling carbs or looking for electrical faults.Cheers,Neil