anti syphon valve

[ralph]

Hi, I have after many years noticed a decrease in wet sumping time. I have an aftermarket valve fitted into the feed line at the rear of the c case (CA10). has anyone had experience of dismantling and overhauling one of these valves?

thanks

[trevinoz]

I would dismantle it and smash it with a hammer so it couldn't be used again. Then go and get information about the results when the valve fails in the closed position.

[ellis]

I fitted a SRM oil pump a few months ago as my A10 wet sumped badly if left for more than a couple of days. After I fitted the new pump it does not wet sump at all. An expensive item but well worth the money.     *

ELLIS

[muskrat]

G'day Ralph.
I'm with Trev 100%. I don't care how many or what type of fail safe mechanisms people use to remind them to turn it on, sooner or later it or they WILL fail.
1: Fix the cause. You might be lucky like Ellis and a new pump will fix it. If not split the cases and renew the ball & spring.
2: Fit a sump plate with a drain plug and drain the sump before starting. That's what I do with my incontinent A7 plunger (will drop the whole oil tank into the sump in 3 weeks ).
Cheers

[ralph]

Yes, I'm inclined to agree a new pump would be the way to go. Possibly the shorter wet sump time would correlate with normal wear in the pump clearances. I have to admit, when I built the engine 25 years ago, I wasn't even aware the valve was there!

[terryg]

Many swear by the SRM pumps but there has also been discussion here of refurbished pumps, if I remember rightly. Also, when I needed a fix SRM had no stock.

I had some success reducing leakage through the pump by cleaning up the inner face of the pump clamping plate, removing the wear caused by the pump gears. I believe worn gear spindles also contribute to leakage, which is more difficult to fix.

[peter small]

I fitted a SRM pump and still wet sumps.
 i asked them when i bought it if it stopped wet sumping they said no,
Fair enough its better as the pumps new and wear is minimal.

They were honest. 

[Dean]

I fitted an SRM oil pump to my wet sumping bitsa A10.....still wet sumps.

Many years ago I fitted an anti wet sumping valve to the Super Rocket. Stopped wet sumping.

Overall I would probably recommend either the orignal BSA solution (ie ride the bike every  day) or a sump with drain plug (the option I've gone for with the Bitsa)

[RichardL]

The oil retaining ball and spring should have been replaced and the ball re-seated along with the pump change or, at least, at the next splitting of cases. Obviously, less work to replace the punp than the ball.

Richard L.

[scotty]

I fitted SRM pump to my A10 for perceived better performance rather than to cure wet sumping.

I'd say that mine wet sumps less compared to my re built original pump but it does still wet sump.

I don't have any external anti drain valves fitted

Come to think of it all of my bikes wet sump 

Draining the sump with the drain plug is just part of the pre ride ritual for me

S

[Topdad]

My two penny worth, having fitted a non return valve and ever so nearly blowing my motor because the ball stuck   ,mid season ,bike used regularly , working fine previous ride to absolutely not a drop coming back next time out  I'd never fit another and am happy to drain the oil pre ride .

[kiwipom]

Hi guys, has anyone ever thought about the possibility of installing an AAV (air admittance valve) 'Bunn' type on the oil tank breather. This would create a vacuum in the tank and would not allow oil to flow 'wet sump' until the pump created a suction thus restoring oil pressure when engine is started, cheers

[muskrat]

G'day kiwipom.
That's a thought from left field. As a matter of fact my A10 Cafe breaths into the oil tank and then to atmosphere through a Bunn. Not exactly the same as your idea but she never wet sumps. Pitty the Bunn Breather is no longer available.
Cheers

[kiwipom]

Hi guys/ Musky, just a thought and throwing it out there for comments, I thought you would like it. Now waiting for someone to rubbish it, cheers

[ralph]

Hi guys, has anyone ever thought about the possibility of installing an AAV (air admittance valve) 'Bunn' type on the oil tank breather. This would create a vacuum in the tank and would not allow oil to flow 'wet sump' until the pump created a suction thus restoring oil pressure when engine is started, cheers

Amazing. for the past two days Ive had a cap head stuffed into the breather pipe based on the same thinking. come home from work today and it looks to have stopped the drip from the crank plug. I have also a rubber O ring that seals the filler cap which should help. The pipe is poking out the drive side under the seat, so unlikely to forget to unplug. Having said that, I'm not sure it would be totally destructive if one did forget. I'm basing this on there being a build up of pressure in the tank - given the scavenge side of the pump is of greater capacity than the feed. So, Kiwipom, i'm off to study your Bunn valve. Ill keep you all posted as to if I find a completely dry drip tray tomorrow after work.