Author Topic: Flooded crankcase  (Read 258 times)

Offline clhiller

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Flooded crankcase
« on: 19.09. 2020 23:58 »
Hello all. I need some advice. The other day I took my 1956 A10 for a short ride. When I parked it, I forgot to shut the petcock and for the first time ever, the float valve didn't close. The next morning I saw a large puddle under the bike. The carb had flooded, filled the cylinders and then the crankcase. I have cleaned the float valve, aired out the cylinders, and drained the crankcase. I will shoot some oil into the spark plug holes to lube the cylinders, but should i try to fill/drain the crankcase with oil to re-lubricate the bearings/bushes? How would I do that? It doesn't wet sump.
 The gas that came out of the sump looked like a 10:1 premix. The oil pump is good and I get return in the tank basically instantly when I start it.


Online muskrat

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Re: Flooded crankcase
« Reply #1 on: 20.09. 2020 10:45 »
G'day clhiller  *welcome*
Yes I've been there, done that.
It should be good to go as there would be oil in the line to the oil pump and start delivering straight away. If your concerned you could pop the inlet tappet cover and pour in 1 cup of oil.
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Online Angus

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Re: Flooded crankcase
« Reply #2 on: 20.09. 2020 12:49 »
Having drained everything, I would take out the spark plugs and push it around in gear until I got a return. At least that is what I did on the A10 with a similar issue.
1961 A7 since 1976
1960 A10 Gold Flash Super Profile Bike
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1950 T100

Offline Swarfcut

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Re: Flooded crankcase
« Reply #3 on: 20.09. 2020 21:25 »
  Any fuel entering the combustion chambers  can only reach the sump by passing down the bores, so you have done the right thing by lubricating the bores via the plug holes. The camshaft runs in its own oil bath trough, and the danger is that this oil has been diluted. Unlikely but possible.  Musky's suggestion of pouring oil down the inlet side means the cam has fresh oil, and also any overflow from the cam trough (with the sump plate replaced) will be scavenged to lubricate the return side of the pump. This will mean a lot less pushing than starting from a completely dry sump to ensure the return side is working.