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oil in crankcase

Posted: Sat Sep 15, 2012 1:03 pm
by brian h
Hi,
I have got into the habit of draining the oil from the crankcase after the bike has been stood for a couple of weeks to avoid smoky startups,recently after draining overnight noticed nearly half a pint of oil in the jug is this the norm, ideas much appreciated the bike is a 92 350 bullet and runs ok.

oil in crankcase

Posted: Sat Sep 15, 2012 10:27 pm
by Norm
Brian,
try a new seal on the crank on the timing side behind the timing pinion

oil in crankcase

Posted: Sat Sep 15, 2012 10:32 pm
by m1ks
I'm newer to the bullet than most on here but.
Are you putting the piston to TDC when you park the bike?

oil in crankcase

Posted: Sun Sep 16, 2012 5:54 am
by John J
When you drain down the crankcase does the oil tank level go down? If it does the wet sumping is via the oil pump. If not then it is via the quill bolt oil seal. Hopes this helps.

oil in crankcase

Posted: Sun Sep 16, 2012 10:26 am
by Gwilly
Norm, i may be wrong and frequently am but i believe the early INDIAN 350 had no seal on the timing shaft.
It ran direct in the crankcase, Hense the need for clean oil regularly changed. Only the early 500 had the lipped seal fitted..... Bit of a booger if thats worn. Machine job and retro fit seal i suppose. Likewise if the sealing gunge/gasket fitted between the crankcase halves is knackered then oil will leak from the tank into the flywheel sump. Major strip down to correct. Hopefully only the cork seal on the pump worm needs attention... can be upgraded with the newer neoprene sealed worm nut. As already said leave the piston at tdc and a container under the open drain plug. 1/2 pint equals bad news. regards gwilly.

oil in crankcase

Posted: Sun Sep 16, 2012 10:39 am
by Gwilly
Good shout John. Edit.... also check tollerance of oil pump flow side.

oil in crankcase

Posted: Sun Sep 16, 2012 2:50 pm
by Beezabryan
if it is otherwise performing OK I would be unconcerned. Put the oil back in the oil tank & carry on. Just one thing to add and that is keep the oil level at half way on the dipsrick as recommended by most folks here (and me)

oil in crankcase

Posted: Sun Sep 16, 2012 8:35 pm
by Norm
I fitted a small brass hand pump to the side of the crosbred motor and before start up give it half a dozen pumps to clear the sump. Always gets a laugh, but it works

oil in crankcase

Posted: Sun Sep 16, 2012 9:42 pm
by Thomas
Brian, try this to locate the leak: Drain the oil tank, refit oil tank screw. Place piston in TDC. Open the sump screw. If oil continuously seeps out (aprox. 400ml) the leak is between timing shaft and crankcase. A leaking feed pump in is not possible since there is no oil in the tank, and it can’t be a defective quill bolt seal because the crank pin is in top position. -----Countercheck: Leave oil tank full. Remove the quill bolt and drain the timing case as good as you can by tilting the bike to the right. Place piston in TDC. Open the sump screw. If it’s leaking now then the problem is the gasket between the crankcase halves, the oil finds its way from tank to sump. Again, in case of a leaking feed pump the oil won’t reach the sump, it would seep out of the quill bolt hole in the timing case.------ Warm up the bike before each procedure, the oil will run quicker then for the first hours.-----My 98 350 had the same symptoms some years ago. Gwilly is right, on a 92 model normally the shaft runs directly in the case and the only way to cure a leak there will be to machine a seat for an oil seal. I suspect that exactly this is your problem as you wrote about “nearly half a pint of oil”, that’s roughly the amount contained in the timing case. If you can’t fix the bike on the spot it is no problem to ride it on, but then it’s best to open the sump plug just after each ride and refit it (and fill back the lost oil) just before the next. I did this for about four month, but it’s quite tiring and also a bit fun killing. Oh, and use dowty seals for the plugs, it is better on the threads as you can work with less torque, Good luck, Thomas

oil in crankcase

Posted: Mon Sep 17, 2012 9:12 am
by Gwilly
So now we have a comprehensive idea how to determine where the leak is coming from. is it a problem to be addressed pronto? probably not. there is of course the nuisance factor but most can be dealt with when engine striped for main bearings/big end work. For now i would check pump operation is satisfactory.loosen quill bolt with engine running,should pulse oil. same for pipe banjos on head to prove return from sump is working.
For £1.25 i would change pump worm cork seal to insure big end is getting a good feed and that the pump flow is not merrily filling the timing chest only due to leakage from the seal. sunday afternoon job. regards gwilly.