White fuel deposit/residue

[djsbriscoe]

Hi,
My RT125 is yet again sans carburettor because it wont idle properly. On removing the carb there is a white deposit on the rubber connecting peice and in the carb venturi. OK I havent ridden it in a while but I run the engine once a week until the fans turn on. Has anyone any clues as to what the white residue may be? I generally use super unleaded fuel or standard unleaded randomly as the bike doesn't get filled up that often. Could it be something in the fuel that causing this? Thanks.

David.

[pwillikers]

My '96 Skorpion Sport was running poorly at mid RPMs but fine at idle and full throttle. I pulled the carbs off to give them a good cleaning and also found suspicious looking white goo coming from the idle jet port. It had a consistency similar to toothpaste left to dry for a few days. It was only present where shown in the venturi pictured and nowhere else in the carbs. In the picture, I scratched a bit off with my thumbnail to show it's depth.

I live in TX, USA. The fuel here is allowed to be 10% Ethanol (E10), and it's just been approved to go to 15% (E15). I'm wondering if the white goo is the fuel tank plastic being dissolved and redeposited here. Any guesses? Anyone have problems with E10?

[kman.45]

My initial guess is water/moisture and oil/fuel mix. My Ducati sight glass often has a white residue on it when it's cold outside and the oil doesn't get warm enough to boil off the moisture that gets in the crankcase. All my Ducati's have done this (18 yrs worth). I've also noticed a white goo on the inside of the oil cap and filler neck on my F150.