Gas in crankcase (2005) GSF1200S

Old 05-31-2016, 11:17 AM
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Join Date: May 2016
Posts: 1
Default Gas in crankcase (2005) GSF1200S

Hello everyone:

I have owned my 05 Bandit for 8 years years now. It has been a super performing and dependable bike. But, when I went out to the garage to take it out last week for the summer, I found that there was (alot) of gas in the crankcase. It appears that gas from the tank either leaked down through a stuck float or bad inlet spring or bad fuel petcock. I drained the old oil/gas mixture and added clean new oil and a new filter. No more gas has leaked down into the crankcase. However, when I took the bike out for a short test ride whenever I accelerate from a stop, the bike is clearly running very rich blowing white smoke behind me. Once I am up to speed 50 to 60 it seems fine.
My question, has anyone ever had this problem with their Bandit 1200? And if so, what was the specific problem: faulty fuel petcock? Carburetor float? inlet needle valve? or?
Again my bike is a 2005 Bandit 1200S with only 14k miles. Prior to this event never had any problem with it whatsoever.
If anyone can provide some insight or an answer, I would greatly appreciate it.
Thank You!
Sincerely, Stones Fan
Old 06-28-2019, 08:53 PM
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Join Date: Jun 2019
Posts: 1
Default Petcock diaphragm

Sounds like the vacuum diaphragm is going bad. They will stick slightly open at first and reseal when actuated. Eventually it will fail. Not sure if the 1200 is rebuildable. Good luck.
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