water in carb --yamaha 15 hp 4 stroke

[lenten]

i am very superstious and would have preferred to have launched on another day but thursday the 13 of sept looked like the best day of the week----trailed the boat down from surrey to warsash----launched and engine wouldn t start---as i squeezed the bulb to prime the engine---fuel was coming out of the carburetor---sat around in the sun for a couple of hours then recovered boat and drove home--next day i took the engine to d+r engineering in walton on thames----they said that there water sitting in bottom of the carb and as i pumped to prime it all the fuel went up over the water and out of the breather -----there was quite a lot of fuel pushed through as i pumped the bulb a lot trying to get it to go hard--------questions---------1 i didn t know carbs had a breather--i thought they were sealed units??----2 any thoughts on how i got water into carb---yes i know its been sucked from the tank---but condensation/fuel tank breather??---3 is there any easy way of draining the carb in situ in case it happens again??-----------when i have a frustrating day like that i always look for a silver lineing-----well i was going to the isle of wight and i could broken down there-------to the new inn at shalfleet which i have now found out is closed-------thanks in advance for any replies

 

[VicS]

i am very superstious and would have preferred to have launched on another day but thursday the 13 of sept looked like the best day of the week----trailed the boat down from surrey to warsash----launched and engine wouldn t start---as i squeezed the bulb to prime the engine---fuel was coming out of the carburetor---sat around in the sun for a couple of hours then recovered boat and drove home--next day i took the engine to d+r engineering in walton on thames----they said that there water sitting in bottom of the carb and as i pumped to prime it all the fuel went up over the water and out of the breather -----there was quite a lot of fuel pushed through as i pumped the bulb a lot trying to get it to go hard--------questions---------1 i didn t know carbs had a breather--i thought they were sealed units??----2 any thoughts on how i got water into carb---yes i know its been sucked from the tank---but condensation/fuel tank breather??---3 is there any easy way of draining the carb in situ in case it happens again??-----------when i have a frustrating day like that i always look for a silver lineing-----well i was going to the isle of wight and i could broken down there-------to the new inn at shalfleet which i have now found out is closed-------thanks in advance for any replies

Yes carb float chambers are vented.. . If there was no way for the air in there to escape you would not be able to fill the bowl with the priming bulb for starters.

Even so, water or not, you should not have been able to overflow the carb with ordinary pressure on the bulb. The float valve should have closed once the bowl was full to its normal level ( or a little lower if full of water).

Tank vent or badly fitting cap the most likely route for water to get into the tank.......... but it could have come with the fuel you last bought! Carb bowls often have a drain plug which you may be able to remove to drain it ......... Your owners manual should tell you how, if its possible

You dont say what year your engine is but the drain is #27 in this diagram

#3 and #5 in this one

 

[lenten]

hi vicS---i was hoping it would be you that replied---the engine is an f15 2003 ---i have looked in the manual but no mention of a drain plug----will look for the drain plug as per your diagram ----i pumped long and hard to force the petrol out of the carb because the bulb kept on going soft-----still mystified as to where the water came from----anyway many thanks for your reply and diagram