Hitchcocks Forum

Hi all I have just finished rebuilding my 500 sixty5 new big end new oil pump spindle and worm new seals and gaskets.
The bike starts and runs well. However when left over night most of the oil ends up in the sump and what I mean by most of the oil' is if its showing half way on the dip stick when I go to bed it shows nothing in the morning. and when I drain the sump from the most forward plug I get about 1/2 lt.

It seams like it just runs out of the tank into the sump, can anyone say what I may have done wrong. All new gaskets have been used.

Hi Terry,
get into the habit of parking it with the piston up the top

Terry,is there any chance the gasket between the oiltank and the crankcase might be faulty or torn?
REgards, Mark

Hi guys--------- MARK M, I see your thinking with that BUT, wouldn't the oil tank get VERY pressured when the engine is running, even allowing for a decent venting system ??......... My feeling is there's a fault somewhere along the scavenge route that the pump overcomes in use but given time the oil runs back into the sump ????

Why would it get pressurised? There is a high level hole between the oil tank and the crankcase anyway. The web and gasket between the two is small, maybe a bit of remaining gasket or sealant got left at one of the studs, enough to hold the two halves apart a bit.

If the scavenge pump copes OK when the engine is running, I'm inclined to agree with Mark M that the narrow gasket between sump & oil-tank may be at fault. Another possibility is the timing-side main-bearing oil-seal could be damaged, loose, or even fitted back-to-front. However, some Bullets do simply seem to be prone to wet-sumping, and making sure you always leave the piston at TDC may reduce the problem (in which case the gasket is probably OK).

I think, given the amount of oil coming through in such a short period it's more than the usual wet sumping through the crank. The oil tank is at the same pressure as the rest of the engine so won't pressurise separately, so don'tbe fooled by that. As a first step I'd have the timing cover off and check the seals. I'd also rule out a scavenge problem as the bike seems to run ok.
REgards, Mark

Hi guys------- MIDGE, whereabouts is this hole you mentioned ?? Can it be seen on any of the drawings ??

The bright spot at the top of the oil tank is the passage into the crankcase.