Author Topic: Small tube oiling on the floor.  (Read 280 times)

Offline Martin

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Small tube oiling on the floor.
« on: 09.02. 2020 14:01 »
Hello i have one questin concerning to one small tube which is oiling too much on the floor. The tube is from the bottom side open and it is located behind the chainbox close to the secondary chain wheel. Hopefuly i was able to describe it enough in detail. Maybe the photo helps you ti get rhe idea what i am speaking about. Thank you. Martin
BSA A10 Plunger 1951, Jawa 250 Sport 1965, Jawa 250 1957, Jawa 350 1956, Jawa 250 1955, Jawa Special 250 1938, CZ 175/501 1959, Jawa Californian 350 II

Online BSA_54A10

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Re: Small tube oiling on the floor.
« Reply #1 on: 09.02. 2020 15:21 »
The tube is the crankcase breather tume.
If there is a lot of oil coming out of it then the oil level in the crankcase is too high
Bike Beesa

Offline Swarfcut

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Re: Small tube oiling on the floor.
« Reply #2 on: 09.02. 2020 15:30 »
Martin. That pipe is the exit from the breather system. Oil vapour and oil will come out here.  Some people arrange for the pipe to exit onto the chain and act as a chain oiler.  Early bikes had a P clip to hold the pipe next to the sump plate, so drips go on the ground. Later bikes only have a small tube, finishing above the chain. The tube was eventually discontinued on later models.

 A little bit of a drip is to be expected with normal use, but if there is a constant stream of oil then that is the first sign of a problem.

 Nice picture, told the story. The tube needs to be supported, and looks as if someone has already cut it short. It just pushes into the crankcase, seal in place with Loctite. Plenty of pictures around showing how it should be.



Offline Rocket Racer

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Re: Small tube oiling on the floor.
« Reply #3 on: 14.02. 2020 03:24 »
Any engine that sits will typically wet sump, (the oil tank drains past the oil pump and fill the cases). one symptom of this can be the breather tube, pumps out some of the excess until the oil pump clears the balance. Racers typically connect the breather tube to a catch bottle which can also be a useful way of seeing how much and when its blowing.
If the bike has a wet sumping issue make a point of draining the sump out of the bottom of the motor before rides and that should ensure the engine doesnt have an oil surplus to start with.
If your engine breather isnt shimmed up hard (by a cork gasket)you can also have problems with oil loss out the breather tube. You can check that by just pulling off the outer timing cover and seeing if the breather fitting has end float (it should be rock solid and have none)

A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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