engine dont turn over

[gearhead13]

alright, an update. we figured out the starter issue im sure your all dying for an answer. when we reconected the grounds we mixed up the negative battery terminal and the positive starter solenoid terminal which made the entire system work in reverse as a "positive ground". in 5 min we had the bike running, but it runs on two cylinders (inside cylnd.) and leaks gas out the airbox are these bikes notorious for leaky float bowls? thansk -sam

Any bikes carbs will leak if not maintained, you need to pull the carbs and rebuild them with new o-rings from Mr. Barr http://cycleorings.com/order.html
The rubber parts (o-rings) get very hard and leak after 20-30 years and need to be replaced. The carbs should be completely disasembled and dipped.

[mike_of_bbg]

i got an 81 gs550, and for all i know it hasnt been riden in years

are these bikes notorious for leaky float bowls? thansk -sam

When the bike hasn't been ridden in years, probably.

Is there a fuel filter after the tank? Rust in there? It doesn't take much to stop the float needle from seating. Sounds like a carb teardown and rebuild to me with new o-rings. Seen BikeCliff's site yet?

[Noxi]

yah that would make sense, the tank is spotless inside but we stripped the carbs and sent them through the parts washer which is notorious for ruining orings.

[Noxi]

could that cause the two outside cylinders to not have fire? or could this possibly be a timing issue...

[mike_of_bbg]

You could have fuel blockage in the carbs on both outboard cylinders. It's highly suspicious though that it's both outers as the inner and outer cylinders share coils. I'd look for spark first. Run it for a few, see if the outboard plugs are wet with gas - if they're getting gas but not spark they should be. Then clean them up, lay the plugs up against the chassis to ground them (plugged in of course) and look for juicy spark.

[Noxi]

yes we checked spark before we ran it, good spark on all 4

[Noxi]

is it possible to have timing off on one coil and the other fine while having spark on all four?

[TheCafeKid]

Not really possible that the timing is causing this issue unless you did something to it. These bikes run a wasted spark system, so even when a particular cylinder isnt in its fire stroke, the plug still sparks. If its starting on two cylinders, and you are getting spark on all four plugs, im still going with the carbs. If you didnt replace the orings, or pull them out before you put them in the parts washer, you'll end up with bits of them in the pilot circuit, which is the circuit of the carbs the bike uses to simply start and idle. Id suggest pulling the carbs again, and cleaning them a bit better, especially the pilot circuit, and replacing the orings in them all. Its not horribly difficult, and you'll be quite surprised how easily that bike will fire right up when the carbs are right. The gas leaking out of the airbox is another clue that the carbs are not right as well. The CV carbs on your bike have no overflow vents, so the gas that isnt getting used because the pilot circuit will not allow it to pass into the combustion chamber has to go somewhere. First place is to the airbox, and unfortunately, the crankcase will soon follow...

[Noxi]

alright thanks for all the help, ill put an order in for the orings tonight and go from there.

[Stefnwolf]

yes we checked spark before we ran it, good spark on all 4

Was that before you connected the battery up the wrong way?
If yes, may have damaged something, better check again.

However, my money is on the carbs.