"spewing oil"

Status
Not open for further replies.
Joined
Mar 12, 2012
Messages
522
so my 73 750 burned oil from the pipes since i got it running. The motor had been rebuilt by a local brit bike shop, i put about 500 miles on it then took it back to the shop to look at that issue (my guess was the oil was coming from the head) so things come up, the owner goes on vacation, etc, it leads to the bike sitting in wait for about a month. Today he got to work on it, calls me up and says "we started it up and it's 'spewing oil' from the motor where the barrels meet the bottom case. Now besides a leaky tach drive this thing never leaked any oil. Opinions on what might have caused this? Could this possibly have been caused by sumping and maybe the pressure from the amount of oil in the sump blowing out the gasket there? The bike never sat that long before since i got it together.
 
Maybe the cylinder base gasket was put on upside-down and the oil just builds up instead of draining out the little teensy -weensy hole thing. Same goes with cylinder head gasket.
 
I would immediately suspect a clogged/blocked crankcase breather hose

somewhere in the line

take off the breather from the back of the timing cover and blow hard through it, is it clear?

if not start taking it off all the way to the oil tank and then from the tank to the atmosphere to find it?
 
haha i don't think we need to sue them yet, they have the bike and are taking the motor apart right now to find the issue.
 
I thought Americans sued each other for entertainment , like that prisoner who sued the Fed. penitentiary system because he didn't eat crunchy (peanut butter). Ha.
 
Torontonian said:
I thought Americans sued each other for entertainment , like that prisoner who sued the Fed. penitentiary system because he didn't eat crunchy (peanut butter). Ha.

No, you are confusing us with Merkin(s). :roll:
 
Torontonian said:
I thought Americans sued each other for entertainment , like that prisoner who sued the Fed. penitentiary system because he didn't eat crunchy (peanut butter). Ha.
i was going to make that joke, seemed shocking to me a Canadian would suggest i sue! :shock:
 
it is NOT spewing oil from the base because the primary is overfilled or the gearbox

again, tell your shop to suspect the bike has a clogged crankcase BREATHER

I have been through this, twice

if it can't breath, it forces oil out exactly where you described, it has under tremendous pressure

tell them to take the breather hose off the back of the timing cover and blow hard in the hose, it should not have any restriction, in fact have them start the bike with the breather hose disconnected and let it idle and see if the oil spewing from the base magically stops

seriously, from there to the oil tank and from there to the atmosphere there could well be a restriction
 
TJK - The shop is the one across the river from us.

Breather could cause the smoking part of it too. If blocked the crankcase pressure could be forced past the rings when the piston goes down.
 
Constricted return can be good for smoke screens too .

Such as a kink or obstruction in the return line/s or a goop of silicone in the sump obstructing pick up .
 
batrider said:
TJK - The shop is the one across the river from us.

Breather could cause the smoking part of it too. If blocked the crankcase pressure could be forced past the rings when the piston goes down.
i could buy the breather being the source of all the problems. I also get a slight weep of oil that sits on top of the crank case where the seem is right next to the breather. Very small amount of very clean oil after running awhile, it seemed like it was coming from the seam due to pressure...also when you first start the bike there is no smoke, takes a moment or two before it shows up, which could be pressure building up....now this spewing oil thing has never happened before so not sure why all of the sudden that reared it's ugly head, but the bike never sat this long with fluids in it either so maybe it sumped and the breather problems on top of that caused melt down. Gonna call the shop tomorrow for an update...
 
Status
Not open for further replies.
Back
Top