New guy. First post. Carb problem

[Guest]

I tried to search and didn't really find what I was looking for. I have a 79 gs550. I bought it with pods and a Mac 4-1. It runs great and pulls hard to redline. The problems I have are the idle hanging up sometimes, and after it gets warm there seems to be fuel vapor coming from somewhere. It looks like between carbs two and three or three and four. Could the two be related? Thanks in advance

[tkent02]

Might be. How are the hoses hooked up? Where is the vapor coming from exactly? And what jets are in the carbs?

[Jmilly]

I don't know the jet sizes. I haven't had it apart since I bought it. The vapor looks like it's coming from one of the tubes connecting carbs 2&3 together. I was also just looking at basscliff and it seems that the last owner may have mixed up the carbs on the mounting plate. On my bike 3&4 have the vent tubes and 2 has the vacuum tube to the petcock.

[tkent02]

That's incorrect, #3 should have the vacuum tube. The identical looking tube on #2 and #4 are float bowl vents. Some 550s have an odd setup, the air screw is on the left side of three carbs, instead of just two of them. This may have led someone to assemble them wrong. If they did this the tubes connecting the carbs together would be wrong.
Does the vacuum line actually work? If it doesn't he could have just hooked the hoses up wrong. Better pull it all apart and see what's up. It's easy with pods.

Last the jetting, I have pods and pipe on my '79 550, running 105 main jets and the needles raised up. The last needle clip position wasn't enough, had to use thin washers to go even higher.
This works well at 6,000' and up, it would be far too lean at sea level. You may need 110 or maybe 112.5, just a guess.

[Jmilly]

Thanks man. I'll tear into it and report back. If two of the carbs are mixed up will I need to re balance them?

[tkent02]

Yes, but that's easy. Do it after you adjust the valve clearances. It's almost always neglected, if neglected it will cause burnt valves, and it will run better if it's done. Changing valve clearance will alter the carb balance.

What other maintenance have you done?

Actually have you seen Basscliff's site? It shows everything you need to maintain the bike properly.

[Steve]

On my bike 3&4 have the vent tubes and 2 has the vacuum tube to the petcock.

Please make sure you are numbering the carbs correctly.

#1 is on the LEFT, as you sit on the bike. That means that #1 is under your clutch hand, #4 is under your throttle hand.

.

[Jmilly]

Ok. It turns out that the vapor was oil from the breather on top of the cam cover. I didn't know it was there til i Pulled the tank. I'm guessing there originally was a hose that ran to the stock air box. Anyone else with pods care to share what they have done for a breather. I'd like to possibly put a filter on there.

[steve murdoch]

Lots of varieties and makers of vent filters.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xk%26n+vent+filter.TRS0&_nkw=k%26n+vent+filter&_sacat=0

[GSCafe]

Lots of varieties and makers of vent filters.
http://www.ebay.com/sch/i.html?_from...ilter&_sacat=0

I use the wee all chrome one. Seems to me the folks are steering you right. Idle hanging or creeping up indicates a lean condition, but for sure rule out something wrong with function before changing anything. It is nice to see someone else indicating similar needle height. I'm closer to sea level and I had to raise 'em higher than I expected. (pods+4-1)