Anti Wet sumping valves

[B25ssSteveA65]

Has anyone any experience of using an anti wet sumping valve on a B25ss. I have heard so many conflicting reports of use of them thatI don't know what to think. Help!

[Spaceman]

It would worry me fitting one of these devices because they can fail if air gets into the pipe between the valve and the oil pump since the valve is opened by pump suction. Unfortunately, an oil return check at the tank won't mean the valve is working because it could just be excess oil being pumped from the sump.

As far as I can see, the only mitigation is using a clear pipe between the valve and the pump so you can check what is happening. I get wet sumping even on my more modern bike (1987) which means that I have to drain the sump manually after leaving it for long periods which is a big pain. Would I fit an anti wet sumping valve - definitely not since a failure of the valve would mean a ruined engine

[DAVE BRADY]

Hi,

I too am wary of these valves but a tip picked up from this Forum is to leave the engine with the piston at TDC.  I have done this and it does reduce 'wet sumping'.   I can only guess that the syphoning affect is reduced because the oil has to up rather than down.  However this make little difference with a worn/leaky main bush or a leaky pump.

Dave.

[cdsdorset]

Get your pump modified with an o ring on the  pump shaft and park at tdc and you probably will have no wet sumping.

[Mike Farmer]

 

I use them without any problem. I have never been shown any proof of failure. I have heard all the "guy up the road told me of a freind of his who had a cousin etc". No proof.

I get the air lock thing, but it can only happen if air can get into the top of the pipe. That means if the oil level drops cpmpletely away. If the oil in the tank is correct, you can suck forever and you can't get any air.

I am curious as to how many of these have been sold worldwide. Just my thoughts.Just checked my A50 yesterday. Oil level completely unchanged since about October. 3 Kicks and oil returning to tank.

My opinion only guys. Take care.

Mike

[idie]

For what it's worth I have one of these valves on my Shooting Star, B33 and M33.

[chaz]

Polly has been selling these since he was in Swindon, more years than I can  remember. If they were as bad as Mike said , a friend of a friend who knew someone whose cousin three times removed etc etc, had a problem then he would have been out of business years ago.
Dont forget, leaving the ignition switch on drains the battery, now, how can we dream up an idea that reminds us to turn the key off??

[berniej]

I use them. They work well.

They just stop oil running from the tank when the pump is not pulling.
Comprising a simple non-return valve - ball and spring - with just enough spring pressure to hold the ball against the seat until the pressure falls when the pump pulls.

How can you get an airlock in normal use when there is a head of oil above the valve? If you have an airlock in the feed it's going to be a problem irrespective of whether a valve is fitted - and fitting a valve certainly won't make an airlock more likely - just the opposite.

I habitually remove the the oil tank cap and check the level and return flow when a bike is started after a period of being laid up regardless of whether a valve is fitted.
Never had a problem.

Cheers,
Bernie

[Mike Farmer]

 

I'm gonna pick up on leaving the ignition on and how to avoid it. Simple method must be available. If I take the key out of my car with the lights on the machine bleeps at me. The same system must be easy to fit to tell me my engine is stopped and the ignition is still on. I shall study this one .

Mike

[idie]

If you leave the key in the ignition and the car beeps at you to tell you it's because the cars ECU is sensing the transponder chip in the key, via the receiver by the switch.

[Spaceman]

I use them. They work well.

They just stop oil running from the tank when the pump is not pulling.
Comprising a simple non-return valve - ball and spring - with just enough spring pressure to hold the ball against the seat until the pressure falls when the pump pulls.

How can you get an airlock in normal use when there is a head of oil above the valve? If you have an airlock in the feed it's going to be a problem irrespective of whether a valve is fitted - and fitting a valve certainly won't make an airlock more likely - just the opposite.

I habitually remove the the oil tank cap and check the level and return flow when a bike is started after a period of being laid up regardless of whether a valve is fitted.
Never had a problem.

Cheers,
Bernie

I think the concern would be that an air leak could develop in a joint either end of the oil pipe between the valve and pump resulting in air being sucked in which could create an air lock and stop the pump working. Checking the oil return before setting off on a journey would confirm everything was ok at that point. However, if an air leak was to develop, it would probably be while the bike was being ridden which would not be easy to spot before damage was done to the engine.

[Spaceman]

Just to add that I had forgotten that many of the later models (post ~1968/69) were fitted with an oil warning light, including the B25SS in the original posting, and this would provide the necessary warning if the valve fails or an air lock develops. So probably safe to fit the valve on these models but a potential risk, however small, to fit them on non oil warning light models.

[JulianS]

If an oil in frame B25 wet sumps consider this service sheet, the bike might be fitted with the defective part.

[Mike Farmer]

   

If you have a point where air can get in you would also have an oil leak. If no oil leak then not enough air sucked in to create an air lock. My opinion. But it is good practice to check the oil return on start up, though even with a complete oil sup full it would still return.

Very good Julian. Going back to ignition left on: a bleeper fitted to the ignition/generator light would do the trick. As soon as the warning light comes on it would bleep and tell you that you were about to be silly. Simples. Now why had I not thought of that before?

Mike

[Stubaker58]

Just buy a Bantam!
No wet-sumping, and some don't even have an ignition switch!
Happy days!