Oil valve solution to oil falling to crankcase

850, mk3. Mine sumps at the same rate. I get a very nice return flow to the oil tank, so I'm happy to live with draining the sump if I've not ridden the bike for more than 3 weeks. I have the AN (plug within the sump plug) arrangement, which I like.
 
850, mk3. Mine sumps at the same rate. I get a very nice return flow to the oil tank, so I'm happy to live with draining the sump if I've not ridden the bike for more than 3 weeks. I have the AN (plug within the sump plug) arrangement, which I like.
So does your MK3 start wet sumping at 3 weeks?
I only ask because I have a MK3 timing cover on my 750 and mine would be more like double that
Even then I wouldn't drain the sump I just let it pump back itself
I have a reed valve fitted so no problems with the primary oil seal as yet
 
So does your MK3 start wet sumping at 3 weeks?
I only ask because I have a MK3 timing cover on my 750 and mine would be more like double that
Even then I wouldn't drain the sump I just let it pump back itself
I have a reed valve fitted so no problems with the primary oil seal as yet
I expect mine starts wet sumping the moment I switch off. It's probably quite quick while the oil's hot. I did leave a tub underneath for a night and it was a very intermittent drip the next day, with cold oil. I have collected 0.7L after 3 weeks. I'd prefer to pop that back into the tank, as it only takes a couple of minutes. I have one of the XS650 breather valves in the breather hose. I don't think that will route the oil back into the tank.

Stuff wears and I doubt everything was replaced when it was rebuilt in 2014 (before I got the bike). I'm reassured it's not a sign of impending doom. So long as it's not inconvenient and works well when I ride, it doesn't bother me much. One of it's endearing quirks! At least it's not leaking.
 
  • Thumbs Up
Reactions: baz
Stuff wears and I doubt everything was replaced when it was rebuilt in 2014 (before I got the bike). I'm reassured it's not a sign of impending doom.

The anti-drain valve in the 850 Mk3 timing cover (or AMR ball valve conversion) should prevent the oil from leaking through the pump but it won't stop it from leaking through the pump shaft clearance so the oil continues draining to the sump even with the Mk3 timing cover but at a slower rate.
To further reduce the rate of drainage the pump can be modified to take O-rings (AMR mod. again) thus preventing the drain through the shaft clearance.

 
Well, my AMR modded bits arrived today.
5 days from Arizona to Sydney, then 9 days from Sydney to here (1500km) - go figure.
Also, USPS "first class" (???) tracking ceased when it got to Sydney.
Anyway - a bit of alloy polishing to do before fitting.
BTW - can't fault the job done by AMR and the instructions are easily understood.
Will keep you posted of results!
Cheers
 
Still getting ready install the new pump and timing cover.
Today "glassed" the rear of the new timing cover. (180 grit a number of times on a sheet of glass before finishing with 800)
It was NOS but still not near flat.
The further you go the more time-consuming it is. At the end you're removing metal over 99% of the area to correct that last 1%.
There are still a couple of small untouched spots (either side of the screw hole, bottom 2nd from left in photo)
I'm certain it will be more that good enough for one of Jim's silicone gaskets
Cheers
Oil valve solution to oil falling to crankcase
 
Well - I have had it installed (for about 2 weeks) and the rate of leakage into the sump has not slowed.
For clarity I have the following AMR mods:
1. The ball/spring on the outlet of the oil pump.
2. The machining + o-rings done on a new Andover oil pump
3. Drilling and blocking of oil gallery to prevent oil returning to oil pump inlet.
AMR suspect the ball (#1) is not seating properly.
I will investigate.
Maybe I'm one of the 50% poor bastards.

What does anyone think of the Holland Norton Works valve at the outlet of the oil tank?
Cheers

Edit: I always leave the bike parked at TDC
 
Well - I have had it installed (for about 2 weeks) and the rate of leakage into the sump has not slowed.
For clarity I have the following AMR mods:
1. The ball/spring on the outlet of the oil pump.
2. The machining + o-rings done on a new Andover oil pump
3. Drilling and blocking of oil gallery to prevent oil returning to oil pump inlet.
AMR suspect the ball (#1) is not seating properly.
I will investigate.
Maybe I'm one of the 50% poor bastards.

What does anyone think of the Holland Norton Works valve at the outlet of the oil tank?
Cheers

Edit: I always leave the bike parked at TDC
Have never heard of any failure with the HNW tank valve... just the need to prime feed line after a oil change i recall.
My next move is to change out the timing cover with the added bonus of a inspection bung.
A circuit cut off tap is probably best... imo
 
Well - I have had it installed (for about 2 weeks) and the rate of leakage into the sump has not slowed.
For clarity I have the following AMR mods:
1. The ball/spring on the outlet of the oil pump.
2. The machining + o-rings done on a new Andover oil pump
3. Drilling and blocking of oil gallery to prevent oil returning to oil pump inlet.
AMR suspect the ball (#1) is not seating properly.
I will investigate.
Maybe I'm one of the 50% poor bastards.

What does anyone think of the Holland Norton Works valve at the outlet of the oil tank?
Cheers

Edit: I always leave the bike parked at TDC
AMR is probably right...

Be sure that the rubber of the seal is past the end of the oil pump bush - so the ball can seal against it. If you install the MK3 cover you will get a different seal and oil pump bush.

I believe (not sure) that a new oil pump from AN requires the MK3 oil pump seal (06-6190) or that the oil pump bush be changed to the earlier type (NM15515) and use the earlier type seal (06-7510).
 
My homemade setup comprising a manual ball valve from hardware store on feed hose from tank with a micro fail safe switch to ign has worked beautifully for some years now. Cost me around $15 in parts and little fettling to make a switch mount plate.
 
What does anyone think of the Holland Norton Works valve at the outlet of the oil tank?
From their webpage description, it appears to replace the tank screen assembly with a one having a ball valve (spring loaded?). Though larger and likely more reliable than the in-hoseline ones out there, it is still reliant on a suction effect from the pump to actually open. The gear type pumps on our bikes make very little actual suction effect and rely on mostly gravity feeding upstream. So I would not run the Holland NW device...even with a pressure gauge/warning light.
 
Mk3 850 with NYC sump breather valve fitted, no issues with wet sumping just kick it over a few times and any excess oil in the sump with be returned to the oil tank. as far as fitting a on/off cut out valve at the oil tank- I may be baised but I absolutely hate seeing them fitted on any bike as they just seem like a disaster waiting to happen......😢
 
 
I have one of these on my 650 CSR & it works. I've also fitted one to a friends Commando with the same result. You simply cannot start the bike until the tap is turned on.
 
This is the one I used, a hardware store Dahl water shut off valve:

Wet sump question?




This had the correct hose barb diameter and the stainless ball valve opens to that same full flow diameter. For the ign interrupt, got a micro push-button momentary, Normally Open switch and mounted it to a bit of Alu flat. The Flat had a hole to pass over the valve barb, right up against the body flange (left side in this pic). Epoxied it to the valve body plus the feed hose butts up against it. The switch position adjusted such that switch is actuated only when the valve is in fully open position, closing the micro switch contacts, which are on the ign power line from main switch.

Been thinking to replace the switch with a fully sealed magnetic reed type switch as it is sleeker and potentially more reliable long term.
 
Last edited:
You can see my MK 111 in the Avatar . This long winter of 5 months she sat awaiting springtime .
Dipstick oil read halfway mark when putting her to bed and read the same before wake up - start up 5 months later , without consciously putting the pistons at top of stroke or anything to prep . She has 30 K. Miles on her now and has never wet sumped . Got lucky I guess . Of course I always fit a breather ( MikesXS650 ) . Enjoy .
 
Back
Top