Hitchcocks Forum

2007 Enfield 350 Bullet Trials with 900Kms on. All oils and filters changed taken for long runs and has Emulsification in the Oil tank.
No sign of the white stuff in the engine. No blockage in the breather tubes.
Using a good quality 20/50. Is this a common problem or is there a fix?
Don't get this problem with my BSA B33 using same oil etc

The B33 had a separate oil tank away from the motor and received nothing but return oil.

The Enfield breathes through the oil tank as well as the crank case which creates condensation in the tank.

Enfield oil also runs fairly cool which makes it difficult to boil off excess water..

It really won't hurt though as long as you change the oil regularly..

I would also be interested to hear any sensible reason for this, I don't think the reason is cool oil as bikes with a separate oil tank have cooler oil without this happening. My Super Meteor with integral oil tank doesn't have this problem nor do any of my other British bikes. Come on guys someone must know. Answers on a £20.00 note please.

Typically it is associated with poorly laid out stock engine breather pipe routing.


Has been discussed a million times previously, but can be a bit of a task tracking down the old postings...


Unless the breather vent off the top of the oil tank has a constant rise up to the catch-can, as opposed to the stock pipe routing with the pipe dipping low beneath the frame cross tube that holds the two triangular gear box plates, the main vent pipe can accumulate water/condensate/elephant-snot at that low point.


Not uncommon for +200cc of water to initially drain out of the oil tank at oil change time.


The main breather pipe MUST have a constant rise to eliminate the condensate accumulation in the breather pipework and the emulsification of the oil in the tank.




I turn the main pipe end-for-end so that the acute bend is under placed the catch can, and the main vent of the oil tank rises straight a curves gently over the frame cross rail, behind the battery and to the catch can.


It is a bit of a squeeze as the pipe is ONLY JUST long enough.

Thanks for that folks. You are correct trawling through previous posts is a bit time consuming but I suspected someone would have a quick answer. Will reroute the breather pipes to see what that does,then I think it will be experiment time.

Although yours is a very late model with the breather exit moved from the crankcase to the top of the oil tank, it's still possible to revert to the older-style breather with the "duck bill" rubber valve pointing over the rear chain just behind the gearbox sprocket. Remove the breather system completely, you can salvage the bits you need from it.



From the breather tubing you need a section with a short right-angled bend at the end, clip the short end onto the oil tank breather union, and cut the pipe so that the other end juts out over the rear chain. There should be a short duck bill valve inside the breather can, take this out and fit it to the end of the pipe you have just cut, using a short length of (eg) 12mm or 1/2" copper tube.





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Just as long as you don't over-fill the oil tank or ride it too enthusiastically (you did say it was the trials version) that will be fine, but excess in either department may lead to a bit too much oil sprayed over the back of the bike. If that is the case you can replace the duckbill with a non-return valve and fit a longer piece of hose to finish at the the back of the rear chain guard, which I had to do with my Electra-X.



The pictures show an Electra-X, which I thinks has a few more bits of piping involved in the factory breather system. If you have a tube leading from the breather can to the back of the timing chest, or one leading to the primary chain case, these need to be blocked off.



Hope this helps



A.

Adrian, yes, your system works but would be better if the breather was routed up behind the battery before descending to the duckbill. This gives any oil that gets out to drain back.

True, but I was trying to replicate as closely as possible the simplicity of the Redditch and early Indian Bullet set-up. My current project will be using one of our hosts' breather/filler neck extension kits for the oil tank to send the oil back where it belongs. A.

I have a 2002 500 Bullet and mine breathes out the left hand side crankcase below the barrel and goes to the Hitchcocks breather mod, no problems at all with mayo whether I do short or long journeys, a good mod imo.

All good stuff folks. I have moved the bean can breather slightly closer to the engine and just under the single seat. The pipes, one from the timing case and the other from the oil case rise into the can.
Tests show so far no simplification. However further testing/time to do. Will keep the breather over the chain mod on file just in case. Now got a slipping and binding clutch God I just love this bike, Do they have Friday bikes in India?