80 GS550E - 3rd cylinder not firing

[caridimondo]

Hi all,

I recently got K&N filters, MAC 4-1, and jet kit installed on my 80 GS550E by a shop here in Brooklyn. They did a few rounds of tuning/syncing the carbs and for a few days the bike was running great. Then all of a sudden it was very difficult to get it started and it feels really bogged down in the low-mid range.

I took it back to the shop and they noticed that the 3rd cylinder is not firing (3rd header pipe cold compared to the others). The spark plug still had spark though. I'm taking it back tomorrow or Thursday for them to look into it some more, but was wondering if anyone else has had similar issues.

Any info/advice is much appreciated, thanks!
Tom

[spyug]

Well it looks like your carb on #3 is not delivering fuel. You had a jet kit installed but were the carbs cleaned prior to? I'd say you have some plugged ports in the carb body or alternatively some gunge has gotten in to your new jets in carb 3. How is the tank? It doesn't take long at all for floaters in the gas to plug something up, its happened to me a few times.

I think you need to have the carbs cleaned and the tank checked for dirt.

Good luck with it.
Spyug

[tkent02]

Do this work yourself or you will never know what's going on in there.

[tom203]

Hi all,


I took it back to the shop and they noticed that the 3rd cylinder is not firing (3rd header pipe cold compared to the others). The spark plug still had spark though.

Third header from right (as you sit on it) ?

[cowboyup3371]

Third header from right (as you sit on it) ?

Third from the right would be the number 2 cylinder. Or is that not what you are asking him?

[tkent02]

Third from the right would be the number 2 cylinder. Or is that not what you are asking him?

Which is the cylinder with all of the vacuum diaphragm issues.

Good question.