GS500e unusual problem!

[TehPoopsmith]

Ok so the story goes like this:
I bought the bike a few weeks ago not running. I get the impression that the guy took a lot of pride in it and i suspect he had just put a new muffler on it (its much shinier than the rest of the bike and the welding doesnt look standard) Anywho he said one of the carbs wasnt right and that he thought it just had something small wrong with it.
So i pulled the carbs off and cleaned and reset the float bowls, changed the spark plugs and away she went! 1st impression was... this is slow.
far too slow for 48 or 52 hp or whatever its supposed to have. much slower than my toyota corolla. anyways i rode for about ten min and it was sounding a bit crook. oh well gotta get home! kept on going. got home and it was spitting sparks out the exhaust! turned it off and looked down the can and it was glowing almost yellow! and stinking like burnt plastic.

SO.

My question is: Is there any mechanical reason for this that anyone can think of or is the only possible reason the muffler?
and would my short ride have done any damage to the engine? Any bright ideas on solutions to the problem?

EDIT: Just checked the spark plugs, only firing on the right cylinder. It would certainly cause the terrible performance but would this cause the problem of the overheated muffler?

[ducatilover]

You might have shit in the muffler causing a pretty serious blockage.

[98tls]

1st up take the muffler off and start it up (not late at night)

[FJRider]

EDIT: Just checked the spark plugs, only firing on the right cylinder. It would certainly cause the terrible performance but would this cause the problem of the overheated muffler?

A fuel rich exaust fumes igniting in the pipes would explain hot exaust can ... and the sparks would be a few bits of (heated) carbon in the can getting blown out.

[nzvlogger]

A fuel rich exaust fumes igniting in the pipes would explain hot exaust can ... and the sparks would be a few bits of (heated) carbon in the can getting blown out.

would be my first thought, did it smoke at all when you where riding?

[GrayWolf]

other possibility, if its a cheapo exhaust, is it packed with fibreglass?? the glow might be residue etc from the manufacturing process thats burning away?

[FJRider]

would be my first thought, did it smoke at all when you where riding?

I doubt if he'd be looking. But fumes from one side of a 500cc twin at low rev's ... I don't think there'd be much to speak of.

[nzvlogger]

I doubt if he'd be looking. But fumes from one side of a 500cc twin at low rev's ... I don't think there'd be much to speak of.

Just thought if it was over fuelling way to much there will surely be a bit of black smoke...

[TehPoopsmith]

Didnt look like it was smoking at all when it was idling or giving it a bit of a rev, as to taking the can off its welded on and i dont really wanna attack it with a grinder unless i really have to. I guess the best thing to do is get it firing on both and see if the can starts glowing again.

[FROSTY]

I'd be asking the last owner as to why it wasn't running. Not to accuse them but to get an idea if its a preexisting issue that might need to be adressede
From there I'd be looking to be sure what I had done was done propperly--ie did you put something together wrong in the "offending" carby.
I'd also look to swap plugs left to right to see if its simply a fouled plug not sparking or if theres a spark issue further up the system,
-I dont recall if they have a single or two coils but if its two I'd swap the power from one coil to the other and swap plug caps over to see if you are getting power to the offending cylinder.

[MSTRS]

The can 'glowing' down inside could be anything, but I suspect it is secondary ignition of the fuel from the cylinder that is not firing.
Fix the spark issue before you do anything else. It is impossible to diagnose many issues in the presence of a known problem.

[TehPoopsmith]

Thanks for the help so far! The offending carby had the float level set too high as the previous owner thought that the LH cylinder wasnt running correctly due to flooding.
So thats what i rectified first and now the carbs to all appearances are functioning correctly (though i will probably have to figure out how to balance them once i have spark). Anyways the reason the left hand cylinder isnt running now is due to it having no spark whatsoever. so i will start by testing the coils with an ohmeter, if they read ok i will try swapping them. i guess if theres no luck there try the source coils etc etc. once its firing on two i guess then i will have my answer!

[FJRider]

Anyways the reason the left hand cylinder isnt running now is due to it having no spark whatsoever. so i will start by testing the coils with an ohmeter, if they read ok i will try swapping them. i guess if theres no luck there try the source coils etc etc. once its firing on two i guess then i will have my answer!

Check the leads to and from the offending coil. Going by the previous owners (lack of) abilities ... it may be a simple fix. A circuit diagram of your bike should confirm (or not) everything goes where it should go.

Possibly the left-hand lead is shorting out. Easy way to find it ... is start the engine in the dark. The short(s) will be obvious.

[TehPoopsmith]

Ok ive checked the coil resistances and they are all in spec and almost perfectly symmetrical too, that includes the pulse generator coils.
Ive checked for shorts in the ht leads (thanks for the tip on turning the lights out - thats a clever trick!) and so my service manual tells me that the only thing left to check is the CDI / Ignition control or whatever you like to call it. So i will probably get that down to the suzuki dealership on friday and ask them who took the sparks out of the spark box - apparently they have tester machines.

If anyone out there has a cdi for a 89-2000 gs500 going cheap let me know!