BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: DGBland on 14 Jan, 2024, 15:32

Title: No oil return at all. New oil pump
Post by: DGBland on 14 Jan, 2024, 15:32
AT MY WITS END NOW
I have just fitted a new hepolite oil pump. I primed the feed side by taking out the spring/ball valve kicked it over until oil came out freely. I put approximately 200ml of oil in the crankcase through the pushrod tube. Basically everything I should do. When I start the bike it is not returning any oil to the tank at all and appears to be just filling the crankcase. The return valve spring and bearing are new. I have tapped the bearing in the timing case to get a good seating. The return valve bearing in the pump is free and not sticking
What else can I try? What else is there to try?
The new hepolite oil pumps get good comments and reviews, I can't see it being a faulty new pump
Any help would be greatly appreciated
David
Title: Re: No oil return at all. New oil pump
Post by: Roy on 14 Jan, 2024, 15:59
First thing I would look at is the new spring you bought ,from some of the springs I have seen they are far to strong ,much stronger  than standard , state the obvious you have the pipe on right way round , I can take a while for oil to return , I would start bike and slacken off the nut that secured spring/ball to first see if any oil is being feed from pump up to crankshaft , another little check the gauze filter in sump is correct way round so hole in gauze lines up with scavenge on pump , be sure pump it's self is flat against crankcase inside and not trapped on the location ring , I always slacken of feed pipe at engine end to make sure no air lock from tank to pump , in this cold weather it can take a while to get through oil tank filte down to pump , also some after market oil tank filters the gauze is finer that standard one , above  may give few thing to try ,

As mention before I have sold and use lots of these pumps and up to date every one has been faultless
All the best hope you get sorted Roy
Title: Re: No oil return at all. New oil pump
Post by: neil1964 on 14 Jan, 2024, 16:04
I presume that you have checked the oil pipes are not kinked and the scavenge pipe in the sump is not blocked?

It is possible to have a displaced gasket on the oil pump gasket or on the timing cover (bottom next to the ball valve).

You did a bottom end rebuild with new big end and replaced the feed quill in timing cover IIRC so presume all internal oil-ways cleaned and hopefully no silicone used (breaks off and blocks oilways)?

Title: Re: No oil return at all. New oil pump
Post by: DGBland on 14 Jan, 2024, 17:12
I think I will have another look at the spring, if anything I would think the spring isn't strong at all and probably a bit weak there seems to be hardly any tension on the spring.
The pipes are on the correct way round and not kinked.
I will check to see that the pump is seated properly and not trapped on the location ring.
I will also remove the return pipe and check there is no debri blocking it or the return feed back into the tank.
Thank you there is a lot of good feedback there. I will work my way through all the suggestions carefully.
Do the rubber grommets in the timing case have much affect. One looks a little worn
Title: Re: No oil return at all. New oil pump
Post by: neil1964 on 15 Jan, 2024, 07:26
The ball valve in the timing cover, rubber grommets are all in the supply line.
The ball valve in the  pump stops wet sumping
Title: Re: No oil return at all. New oil pump
Post by: Bess on 15 Jan, 2024, 14:54
Hi,
     Worth a read, pressure in the oil tank works for me.

Best wishes...
Title: Re: No oil return at all. New oil pump
Post by: neil1964 on 15 Jan, 2024, 20:36
Here is the diagram:
(https://www.bsaownersclub.co.uk/forum/proxy.php?request=http%3A%2F%2Fwww.dansmc.com%2Fbsa_b31_oilflow.jpg&hash=cd4ad8302c0a571b95f2649323b6108ede99bd7e)
http://www.dansmc.com/bsa_b31_oilflow.jpg
Does that help?

Looks like I cannot insert HTML for a web diagram?