Wet Sump Symptoms

Just to be 100% sure, could y'all explain to me what the symptoms of wet sumping are?

Thanks

Bike's been sitting a while. You look in the oil tank - low or empty. You start the bike and within seconds oil is being returned to the oil tank - you can see it with the cap off, the return line is near the top. After running for a while, the tank is now back to its proper level.

The oil is supposed to stay in the tank, but it slips past the oil pump into the sump. Running the engine engages the pump, which pumps the oil out of the sump and back into the tank. Until next time...

The other type of wet sumping is with 72's where the scavenge pick up is located toward the front of the case. Under sustained higher RPM running, oil is flung to the rear of the crank case by G's and the crank flinging in that direction causing some cavitation and starvation.

This would also flood the breather cavity there by pushing oil up the breather and increasing pressure and oil leaks. That why i like the reed valve higher on UNmodified crankcases. Blow on a saxaphone, then fill your mouth with 50 weight oil and try blowing through it again to get my point.

This was said to be the cause of many Combat failures, along with other stuff.

Read this.....
http://www.oldbritts.com/n_c_case.html
and this.....
http://www.oldbritts.com/38_240010.html

pvisseriii said:

The other type of wet sumping is with 72's where the scavenge pick up is located toward the front of the case. Under sustained higher RPM running, oil is flung to the rear of the crank case by G's and the crank flinging in that direction causing some cavitation and starvation.

This would also flood the breather cavity there by pushing oil up the breather and increasing pressure and oil leaks. That why i like the reed valve higher on UNmodified crankcases. Blow on a saxaphone, then fill your mouth with 50 weight oil and try blowing through it again to get my point.

This was said to be the cause of many Combat failures, along with other stuff.

Read this.....
http://www.oldbritts.com/n_c_case.html
and this.....
http://www.oldbritts.com/38_240010.html

Click to expand...

I need to do a video of by bike when it wetsumps. It's pretty interesting. Of course I need to stop riding it first. :mrgreen:

This may sound like a stooooopid question, but is wet sumping really detrimental to the bike? What does it hurt? Is it really worth it to spend $70 or so to buy and install an anti siphoning valve? I mean, hell, never had one from the factory......... Well, never had many things from fatory......

You know, I only started worrying about it when I got on this forum and saw all the people installing valves, etc. My bike has always lost nearly all the oil in the tank to the engine in about 2 days. I never worried about it before, because I didn't know, and the more I ride it now, the less I worry about it. It may push out a bit more oil on startup into the breather, but so what. It finally all gets back into the tank in probably less than 30 seconds and seems to work fine. And I've got the timed breather on the LS of the crank. Unless you are have big oil leak problems I wouldn't worry about it.

Dave
69S

Two things can happen that I can think of.

The lessor of the evils is that the bike becomes really hard to start as the crank is trying to spin in a crankcase full of oil. My Interstate was like this. Had to drain the oil before it would start.

Or the pressure could blow the seals out. One of the worse would be the one on the primary side.

WIth a breather on the crankcase the oil just goes out nicely. Like I said, video pending.

Opinions on this item I just found..... at least half the cost of most.


http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... ink:top:en

What happens if it fails closed? Are you willing to put up with that risk?

Dave
69S

Good point Dave.
Also found this one.
If you had a decent workshop you should be able to whip up a similar thing yourself.

I have used a 3/8 ball valve with the handle sticking out toward the kickstart. loop a ire over the foot rubber as a safety. Many have incorporated limit switches to lock out spark. many other have forgotten to turn on the valve and lost the engine, similar is the oneway valve that stuck shut and also lost engine.
Your ingenuity and your call.

Not full proof but better is the MKIII timing cover along with someone around here who does a mod on your cover. Look it up.

I may be hijacking the treas I began, but why does the Motorcycle parts industry charge so much for such a simple device as a one way check valve? I have seen them from Norton Parts Suppliers for over $70 PLUS shipping. I have also seen similar one way check valves, 3/8" made from aluminum and brass for under $10, pluse shipping. I guess what I don't understand is why such a disparity in pricing? Is it because we are naive enough to pay it?

Sorry, for my rant

Hi, I had used on several friend's Norton a manual valve but with an electric switch which enable the bike to start unless open, it is made by a fellow in UK member of the Matchless Owners Club, but to be honest on my own 850 which suffer wet sumping too , I just start her and lets oil come back in the tank, may be one day.............

My bike is wet sumping and filling up the chain case with engine oil, noticed the clutch was slipping under full power and the oil was dropping when left to park.

Suggestions on easy fixes ?, not too keen on a one way valve, would prefer a tap with an ignition lock out switch.

Hey Josh

You telling us you are actually getting out on the bike.. been real crap " up stairs "..

I could have got in a run this after noon but never happened ~ been so miserable up here ~ quite amazing considering we are only 75 clicks apart ~

My bike has wet sumped for YEARS ~

I give up worrying about it ~ and when I start up I keep revs low and let it idle as low as possible ~

I think the PCV valve ihave fitted to the breather actually helps and takes some of the potential pressure off the sump and thus I have managed to successfully retain the drive side seal intact after all these years..

No easy fix there Josh.. but no huge job as I know it.. strip out the primary and replace the seal! ( Correct me if am not right there ; blokes ~ )

Final comment from Les Emery's Norvil shop web site ;=

http://www.norvilmotorcycle.co.uk/

WARNING - DO NOT FIT ANTI DRAIN VALVES INTO FEED PIPES - IF YOU USE THE CORRECT OIL (MONOGRADE SAE 50 - NOT 20/50) AND ALWAYS LEAVE YOUR BIKE ON COMPRESSION, IT SHOULD TAKE 9-10 MONTHS TO EMPTY YOUR OIL TANK (5-6 MONTHS SINGLES). IF IT IS LESS, FIX THE PROBLEM - DON’T ADD TO IT! - RING LES ON THE TECHNICAL LINE !!

Page last updated 12/07/11

Perhaps my drive side seal has popped out........

Stuart,

What are you talking about, I was at Yungaburra on Sunday, is was a lovely day :

Well ~ ( OK ~ I fess up ~ last Sunday I was post shyte faced ~ and rule one wih me ~ Grog and M/C DON't mix ~ and I learnt that lesson the very very hard way! )

But ~ actually just from Yungaburra and Atherton to Malanda it can be crap ~ I have often taken a punt and find it is fine at Atherton when it is raining in Malanda. (I was warned when I told by a former work mate that when I planned moving to Malanda ~ from NSW !, that it is dubious weather in Malanda ~ :roll: )

And I was chaffing at the bit about it too ~ And Hey ! That looks liek it was a great roll up ~

Josh ~ is that your Commando ? Or were you on the Goldie? I spose you that Commando side panel with you just to boot eh ?

Inspired.. have to get there this Sunday ~

See a few familiar faces there too ~

Josh Cox said:

My bike is wet sumping and filling up the chain case with engine oil, noticed the clutch was slipping under full power and the oil was dropping when left to park.

Suggestions on easy fixes ?, not too keen on a one way valve, would prefer a tap with an ignition lock out switch.

Click to expand...

Josh -

My bike had the same problem. If left to sit for two weeks it would wetsump and quickly fill the primary to boot. Took me a bit to figure out where my insane oil loss was to. I was very close to fitting a wetsump valve in frustration (draining the primary is a real pain...). Someone cheeky will say I should just ride the bike more often, but I'm in the military and when you're on the road it's hard to say when you'll be back.

Removed the primary to figure out what was going on. Crank seal was missing. Not sure if it came off somehow or was never there in the first place (some have said they can work loose), but in any case replaced it. I did have a PCV fail (motormite, since upgraded to the XS650) which definitely made a huge difference in oil leaks *everywhere* so perhaps the seal came off and subsequently was lost when the case pressurized. Also put locktite on the studs when replacing the primary, as I was told oil can migrate through those as well.

That was two weeks ago. Haven't had it wetsump enough since then to see if that made all the difference. Even though my bike is a Mk III, this winter I intend to have the AMR mod done to my timing cover to help mitigate the wetsump as well.

Cheers,

- HJ

Stu,

Both the Golden Flash and the Commando are mine, a friend ( well this dick I know ) rode the other.

Thanks Joe, looks like I may have fixed the issue, a previous owner has drilled two holes in the cases either side of the LH main bearing ( to push out the bearing cases ), the holes appeared to be the source of the oil, no doubt the engine is wet sumping a little, who cares..... filled the holes with epoxy glue, time will tell.

Holes can be seen here: