my motorcycle has an oil leak from the breather pipe pls help?

Question

hi all , i have a yamaha xj 600 n and after a ride of 25 miles or so when i switch off the engine it gushes oil out of a breather pipe between the engine and the rear tyre. it only leaks for about 3 mins then stops, the bike was serviced 2000 miles ago and runs very well please help regards all Russ

Answer 1

I used to run a fleet of these XJ600s for the rider training school I worked for and this was a common problem. The airbox acts as an oil separator for the emission control system and if the drain hose blocks, then oil will build up in the airbox and drain out of the external drain on the left side, whenever the machine is put on its sidestand.

The fix is to remove the tank to get at the airbox. At the rear underside of the box between the centre carbs you will see a black plastic "T" piece joining the main crankcase breather hose, the cam cover hose and the airbox. This T is blocked with emulsified oil and will not allow oil to drain from the airbox back into the crankcase.
Remove the T and clean it out and your problems will be over for perhaps a couple of thousand miles.

A quicker way, though not as good is to pull the crankcase breather from its spigot and blow compressed air up the hose, though you can't guarantee that the air filter will not get splattered with oil.

This problem only occurs in cold damp winter weather as does occasional carb icing.
Other winter probs are the main relay connection (black box under R side panel) to the starter solenoid corroding and failing. Remove the block connector and smear with vaseline to prevent this. The neutral sensor terminal (white plate, 3 screws, light blue wire, under the G.Box sprocket) corrodes and fails regularly.
The rear sprocket carrier bearing should be renewed every time the chain and sprockets are changed, as they are known for failing regularly (size 63/22 2RS).

Othewise this bike is bullet proof.

Oh and keep the swing arm drain holes just in front of the chain pullers clear or water will build up and rot the arm.

Answer 2

Bart is right about the blow by. That breather is there in case fumes from the combustion chamber pressurize the crank case. The pressure will push oil out of that pipe, as you've seen. You may need new rings, cylinder head or head gasket. Talk to a reputable Vespa mechanic in your area.

Answer 3

Possibly the wrong grade oil or too much has been put in. If too much of a lower speck oil is used it breaks up and becomes a lot thinner resulting in coming from overflowes. If too much oil has been put in this can also occur. Id check with garage who serviced it, was it the same before going in ofr service?

Answer 4

I BET YOU DO SMALL JOURNEYS???????
THE BREATHER RUNS UP TO THE AIR BOX ON XJ600N DIVERSION THEN DOWN, YOU GET A BUILD UP OF CONDENSATION & CONTAMINATED OIL WHEN GETS WARMEDUP THE WATER EVAPORATES BINGO GUNGE OUT OF BREATHER ,
CHECK OIL TO SEE ITS NOT CREAMY, TAKE BREATHER OF SIDE OF ENGINE & BLOW UP THE PIPE SEE IF BLOCKED,
CLEAN AIR BOX OUT ITS A PRAT AS ITS UNDER TANK,
I HAD THIS WHEN I FIRST GOT MINE ITS OK IN SUMMER JUST THE WINTER, I FITED A DRAIN PLUG BETWEEN THE ENGINE & AIR BOXX IT HELPS & DOES NOT AFECT RUNNING

Answer 5

Rings

Answer 6

oil pressure too high , get it to a garage asap or the head gaskit could blow.

Answer 7

possably crankase pressure to much as piston rings are letting cylinder pressure go by pistons into crancase.

Answer 8

could it be poss that there is too much oil in it?

Answer 9

are you a chick? with a motocycle? my god whats happening to the world?