moisture in catchcan

I just installed a catchcan on my 750 fastbackback oiltank about a 1,000 miles ago (it has never seen rain or sit in it).

I have noticed when I dump it their is probably 90% water(I am running valvoline mono 50 weight)


Any ideas what that means.

Total speculation, but I wonder if hot oil goes into the catch can, and then as it cools draws air/water vapor in, which condenses and collects in the catch can? Have you checked the oil in the tank - not the same problem, I hope/assume/query?

'Bout all I can come up with, theory wise. Will be very interested in what other folks think.

Glad you mentioned that because when I look at my dipstick it seems to have(I believe the proper term is condelusive oil) in other words water on it.

Other than that the machine runs like a bat out of hell, especially since I have been adding lucas octane booster to the gas. It starts better idles better runs better.


Cheers.

My 69 fastback has water droplets on the oil tank cap every time I ride it short or long trips when I remove it after the ride. I have removed it every time I ride it while hot and sit the cap on the hot head and all the water is evaporated. I replace the cap after the water has evaporated and next stop its back again. The pipe work is set up with the line to the air filter and it has condensation in it all the time. My next plan is to put a catch bottle and blank of the air filter. Hope then the water will only be in the bottle and not on the cap.
Ian

That's it, It does the same thing on my Buell, I have been told this is normal when you do short rides and the oil does not get a chance to boil out the condensation that is drawn in while the bike cools. This is also why almost all transmissions show rust inside, When the air inside cools it also draws in air that has moisture. How long are the rides you take? I don't remember where I heard it but it can also cause oil tanks to rust out at the bottom.

Hortons Norton, Yes you are right about the short trips and condensation. Last Saturdays ride was 50 km round trip in the morning on the freeway at 100km/hr most of the way and on returning home removed cap and water on the cap, milky on the cap :shock: Ride after lunch about 45km and on return water again. Our summer 27c not cold like you side at the moment. Would expect condensation in winter but not in summer and the tank is hot , must be in the design of the tank :mrgreen:
Ian

All these replies make sense of oil not getting hot enough.

Today I am going to try 200 miles with little stopping. the temp outside is going to be around 70 so I will see if that shit burns off, like I said I am running straight 50, maybe thats to thick for windy yuma

I read somewhere that ideal temp for good lubrication is between 180 and 220 f.



cheers

I read somewhere that ideal temp for good lubrication is between 180 and 220 f.

Click to expand...

That's pretty close to what a Spectro engineer told me. The temperature would be measured in the oil tank.

Hi,

I had the same problem with my '74 850.

Condensation builds up in the motor and escapes via the crankase breather hose to the oil tank and appears as sludge under the oil tank cap.

I followed good advice from an earlier post on this web site, drilled the inlet rocker cover and fitted a 6mm breather pipe vented to the ground.

The result is that any water vapour exits through this breather instead of being forced into the oil tank and contaminating the oil. Most Jap bikes have breathers from the cylinder head why not Norton?

Plus I am no longer troubled with oil leaks from the tacho drive and the exhaust rocker covers.

happy Skoti

I went for my 200 mile blast and seem to get rid of most of the moisture.

But I think I will try your breather tube from the rocker cover.

My questions would be how much oil/water do you collect in this. and do you put a oneway breather on it?


thanks.

mcns Like you I went for a longer blast not as far as you on Saturday and for the first time there was no oil/water sludge on the cap. I had been out in the morning and cleaned of the muck on return and left the cap of while I had lunch. Most of after lunch ride was on the freeway 60mph/100km and the oil was a lot hotter so I guess we need to ride them more and for longer like they were made for and not just a pampered toy. :mrgreen: Mines never been in the rain since I have owned it. The gear box is a worry with no seal on the clutch cable access point on the cover plus the small hole in the inspection cover. Like a four wheel drive diff into a creek crossing when hot it would suck in water. My two gearboxes had moisture inside when I pulled them down and photos of gear boxes on the web most show some signs of moisture. Im waiting for Jeandr to show what he has done to overcome this then pinch his idea.
Ian

Scuff I think I will take skotis advice and also make a similiar breather for the gearbox,. Breather holes for any breathing machine (plant ,animal or mechanical makes sense.


cheers

mcns said:

I went for my 200 mile blast and seem to get rid of most of the moisture.

But I think I will try your breather tube from the rocker cover.

My questions would be how much oil/water do you collect in this. and do you put a oneway breather on it?


thanks.

Click to expand...

No oil seems to come from this breather only water vapour. You can test this by temporary fitting a clear plastic hose, start up from cold and watch the moisture venting away.

I don't have a one way breather fitted.

I drilled the upper part of the rocker cover above the stud fixing and threaded it M8, then loctited an adaptor in place to take a 6mm hose.
To prevent the engine vibration working the adaptor loose in the rocker cover I used very soft flexible neoprene rubber hose which I routed back along under the main frame spine and through the wiring harness gusset then down past the R/H rear of the air fiter backing plate.

Good Luck