Hitchcocks Forum

I have oil leaking through the distributor on the left side, where the contact breaker points/electronic ignition is. I suppose that means replacing the oil seal ?
Did someone already experience this? The strange thing is that this coincides with the installation of higher output oil pumps. Could this be related ?

If it's the sort with grease nipple then I've found that over enthusiastic pumping with grease gun can force the seal out behind the distributor weights - well, mine did anyway! At least it is easy to access from within distributor. I deleted the nipple and replaced with easily removed plug, a few drops of oil now and again seems to be enough....

Logic would dictate the oil seal has let go. That said, it shouldn't be pressurised (much) in there and I'm amazed oil has managed to find its way up that far.



What model do you have? Is it one with a conventional crankcase breather running from the casting just below the barrel on the left hand side or is it one of the later ones with the catch can and breather stub on the oil tank and return stub on the timing chest? If the latter, check everything is breathing properly and not choked up with gunk.

Yes.


Steel or Bronze pump body? The ones our Host supply (bronze disc) have correctly drilled port timings, too many After-market pumps DO NOT!


I have seen far too many Cheap & Nasty High-output oil pump sets that utilise a Std return pump disc to the feed side. They look like they will work OK, but the Disc drillings are incorrect; the drillings should be different from feed - return. The port timings are offset by 1/8"


IF you did not finely lap the new pump discs onto their respective seats you WONT have full pump disc seating, and the oil WILL be internally bypassing. Pull the return pump, in particular, and check to make sure the disc is not showing ANY scratches or scores, and that it is seated properly.


It pays to check both discs and seats; they should have bedded in by now and will have 'polished' up and show up any high/low contact areas...

Very interesting replies, and thanks to everyone.
P, I did do some overenthusiastic fat pumping some months ago, and fat ended up between the twin coils and magnets (Boyer ignition). That caused some unexplicable engines stops, until I removed the fat.
Stinkwheel, it is a conventional crankcase breather running from the casting just below the barrel on the left hand side. It is a Jan 1999 500 Bullet.
Tim NZ, the pumps have a steel body. I probably should have ordered them from our host. I noticed that especially the scavenge pump produced more pressure. I had to be a bit more meticulous with the sealing of the banjo fittings and the rocker covers, which previously had not leaked. I had replaced the pumps because the feed pump seemed worn. The test with the fingers on the holes produced very little pressure.

Excessive pressure in the return side is a leading cause of Stripped oil pump drive worms...


Fit an Oil-pressure relief valve in the return! If your engine is prone to Wet Sumping, DONT rev the motor until the sump has cleared and the oil level in the tank has returned to normal.


Rev the motor with a sump full of oil and oil pressures go Sky high.