79 xs1100 problems

[spec1974]

ok, so my bike had been running pretty good probably put 200 300 miles on it with no big problems, i park the bike for 3 days during those days its raining and my bikes outside. When i go to ride it to work on the next nice day, the bikes first and second cylinder are sputtering like they are running out of gas and the bikes bucking like a bastard. I let the bike sit for a day thinking maybe it just needs to dry out, start it up the next day and have the same problem , i ride the bike to the gas station put some dry gas in it and the problem doesn't change. I ride the bike maybe 10 miles bring it home, now the first and the second cylinders arn't firing at all in fact i have gas pouring out of the exaust on the left side of the bike, i know i'm getting spark, does any one have any suggestions. Remember the bike ran fine, then i parked it , and it got rained on, and now two cylinders arent firing at all
Thanks
Rob

[randy]

Install new plugs in one and two. My guess is that the rain soaked the plug caps, caused intermittent firing, which then fouled the plugs. HTH

Randy

Welcome to the forum. What's your location?

[ratbyk]

79XS Problems

spec1974, I would guess that you have a couple of problems:
1. The petcock on the side of the tank that feed carbs 1 & 2 is not shutting off while parked.
2. The needle & seat for either #1 or #2 carb or both of them is not shutting off when their fuel bowls are full.
These flooding carbs is why you are down 2 cylinders. Plugs will be soaked with gas. If you are getting fuel running out the exhaust pipe then there is a good chance that your engine oil is getting contaminated as well.
With the petcock in the run or reserve position pull the fuel line off. With engine off no fuel should flow. There is a vacuum controlled check valve inside the petcock. Possibly it is stuck open or has dirt on it's seat and is not shutting off the fuel flow.
To determine which carb is flooding, loosen the hose clamps that retain the rubber trumpets that connect carbs 1 & 2 to the air box. Slip these clamps well to the rear out of the way. Pop the bottom portion of each of these hoses up from the bottom portion of the carb intake air horn. Gas should dribble out of the throat of the faulty carb.
Another thought, dirt could be causing the problems with both the petcock and the carbs. Rust, scale, some foreign objects has run down from the tank and has caused both the fuel check valve and the needle and seat to be stuck in the open position.
After you have corrected both the carb and petcock problems be sure to install in-line fuel filters to stop this problem from re-occurring.
I would also put a stick down into your engine oil at the filler cap. Step away from the bike and put a match/lighter to the oil on the stick. If it flares up change your oil and filter before running any more or you will be buying main bearings as well.
Sorry to bear bad news.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"

[Bud Manley]

I had a similer problem. I swapped the plugs from 1 to two and it seems to have helped. I should just buy new plugs but thats just too much money for me to spend.
(Do I get extra credit for using all instances of spelling for too?)

[spec1974]

ok, so i've changed the plugs, changed the oil took the carbs off and made sure that theyt were clean and the bike still doesn't run if i leave it at a real low rmp like 800 or lower you can hear the first two cylinders sputtering. And every once and a while it will back fire and start running for a second and then die. I'm at my whits end, i don't understand how the rain could make my bike run like this
Thanks
Rob

[ratbyk]

Idle Speed

Idle speed should be 1100 to 1200 RPM when the engine is warmed up. The sputter from 1 and 2 sounds like your idle mixture is too lean. Back out the idle mixture screw 1/2 to 3/4 of a turn. They are located at the top front of the carbs just before the carb slides into the intake manifolds.
Have you synched the carbs yet?
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"