Hi, I wonder if someone can help me, I have a 1965 Lightning Rocket which is wet sumping dreadfully.
When riding the bike, after about 15 miles or so the oil starts coming out of the breather.
On a bad day when the sump plug is removed I can get up to a half pint of oil out.
Once cleared the bike starts and rides perfectly until the sump fills again.
I have removed the oil pump and cannot find any problems and it is turning beautifully by hand, I have gently re sealed both sides with wellseal and replaced the gasket, I have also replaced the pressure relief ball and spring.
When the bike is at tick over the oil return is excellent and responds well to the throttle, I have fitted a clear portion of pipe to the rocker box feed and I can clearly see that it is getting a good oil supply.
If left overnight I can get about a quarter of a pint of oil from the sump. Is my pump causing the fault or will a anti sumping valve cure this problem.
Tony
Hi Tony
Just to clear it up, are you saying that starting off with the sump drained, after a few miles running its full of oil again? Also, are you starting with the oil tank overfull?
I have anti wetsumping valves on both my bikes and they work a treat, but you may have a different problem.
morning Tony,
When you checked the pump you say you replaced the ball and spring that sits behind the pump? Did you check the seat where the ball sits and was it unmarked and the ball sat nicely on it? Some gaskets interfere with the ball so check that. Also, do not over tighten the pump nuts as the pump can be distorted slightly.
Have you checked to see if the return pipe and ball in the sump are clear and in place. I have had the pipe come out of the case giving the symptoms that you describe as too much oil sits below the hole and is picked up the crank and eventually comes out of the breather.
A 1/4 pint over night after the bike has been running is not too excessive as the oil that was flung about the crank etc. drains down to the sump. The 1/2 pint after running the bike is.
The return capacity of the pump is double the feed so once the pump scavenges the initial pool in the sump it will start to draw some air so the returning oil will look a bit frothy.
I would suggest going through everything again just in case.
Dave.
Hi Dave,
Thank you so much for responding to me, I didn't replace the ball and spring behind the pump as I thought this was best left with the existing in case that I ended up putting a mismatched item there, the ball and spring were in perfect visual condition however I did replace the pressure relief valve ball and spring. I was aware that the ball needed a little clearance in the gasket and the one that I fitted a had a larger hole to account for this, I also made sure that no excess sealer was around this area, before fitting I also linished the mating face of the pump. You mentioned the return pipe and ball in the sump are clear and in place, I haven't checked this but will do so today.
Seat the ball on the back of pump body to ensure a seal as the service sheet below.
Sounds like the feed side of your pump is overwelming the return side. Does your engine have the SRM or Devimead crankshaft needle roller end feed conversion?
The reason for asking is that I experienced a similar oil build up on my SRMed A10 and the cause was a damaged end feed oil seal. New seal and the problem was solved.
The other though is a partial blockage in the oil line between sump and tank which could be caused by the line being damaged or squeezed due to being routed.
Hi Tony,
Have you checked the gauze on the sump plate. My A65 had debris on it (excess silicone sealant used by previous owner) so holding oil back from being pumped back to the tank.
Hi,
Thank you all so much for your knowledge, I have just removed the sump plate, no debris I am happy to say, took the plugs out and placed a finger on the scavenge pipe and there was suction, not a lot but definitely suction, I will run a pipe from that to a jar of oil to see if it visually shows suction. In answer to the question I have no idea if the engine has an SRM or Devimead crankshaft needle roller end feed conversion as I didn't rebuild this engine regrettably, however the person unknown that did knew about SRM as it has the SRM sump plate. In answer to the other question, after draining the sump and taking it for a ride the sump has been filling up, so at rest and in use I have the same problem. I have just returned from my good friend's engineering shop and as you have cleverly mentioned and kindly provided a works bulletin, the first thing that he said to me was to set the seating on the pump with the bearing or it may as well not be there. I will strip the pump out again and set the bearing correctly, I will update this post when I, with your help have solved it.
Thank you all again.
Tony
I was advised that leaving the bike on the compression stroke helps reduce sumping....
If mine is left for more than a few weeks I drain the crank ..... gets up to a 1/4 of a pint ....
and pour it back into the oil tank before starting.
Mine has a fairly recent (3 wish years ago ) SRM fancy blue billet pump too,
Best
Matt
:) :) :) :)
I have an A50 with an in line anti wet sumping valve and after standing for about 18 months it was fine. I have an A65 that wet sumps for a pass time with a SRM billet pump and new check valve spring and ball.
Mike 8) 8) 8)