Breather

[Offshore]

My 70 traveller blows oil all over the place but until I can afford to have the engine out and resealed I am looking at checking breather system for blockages.

What does the bean can thingy do on the carb side of the engine. Do I need to remove it and clean it out and if so how do I remove it from the engine block.

I assume I can clean the pipe from the bean can to the carb with a pipe cleaner?

Anything else I can be doing to ensure engine pressure is correct and it's breathing ok.

[philthehill]

The bean can thing is the oil separator and has a wire gauze fitted inside it. They sometimes get blocked which causes the pressure in the crankcase to increase especially if you have piston ring blow past as a result of worn rings. Take the bean can off and make sure it is clean and can pass air.
The pipe can be cleaned as you say but make sure that the pipe and carb aperture/PCV (if fitted) are clear and the PCV valve diaphragm is serviceable.
If you have a pipe from the rocker cover to the air cleaner make sure that it is all clear.
Make sure that you have the correct oil filler cap on the rocker cover fitted.
A picture of your breather systems is worth a thousand words.

[Offshore]

Hi Phil thanks for the reply. How do I remove the oil separator? Been looking for a while and cannot see how to do it or open it up. No pcv fitted just rubber tube from separator to carb.

Will post a picture tonight.

Vented filler cap fitted although mechanic says it does not seal properly on the rocker cover. No offtake on rocker cover for breather pipe to air cleaner.

[bmcecosse]

Just a single screw (1/2" AF) removes the side cover with can...... Wash it out till it's clear.

[Offshore]

Hi guys. Cleaned out the breather and pipe with solvents and degreasants. No significant oil or sludge. All fairly clean really.

Replaced plate using new gasket and rubber washer under the bolt head.

Engine sounds quieter or am I just paranoid!

Thanks for the advice all. Much appreciated as always this side of the water.

[whyperion]

What is the 'correct' filler cap? I seem to have . Metal One - an old style , Plastic Flat one, Plastic Deep with some kind of Gauze (fume filter?) - which suggested replacement over a distance - goodness knows how far it may have travelled. Multiply permutations by about 2 at last count.

Also rubber washer under bolt on tapped chest side cover, any particular type (fibre better?) or plain flat, mine unknown as fell to small bits when I undid bolt.

[les]

The cap depends on the breather system you have. Not sure what you mean about 2 x permutations, it didn't make sense to me.
The side covers are secured by bolts that are fitted with concave washers that hold rubber O rings.

[bmcecosse]

The old metal cap fits the older rocker covers. The plastic cap with gauze is the result of very muddled thinking - don't use it unless you like breathing oil fumes... Use the solid plastic cap - and good suction on the crankcase breathers. Rubber flat washer will be fine...you can buy them from the usual suspects, but I fancy the £1 pack in Poundland will have something suitable !

[philthehill]

As above - the type of oil filler cap is dependent upon the engine breathing system fitted.
The original convex cam follower covers (front cover with tube) 948cc (Pt Nos: 12A1382/1386) uses the flat fibre washer for the bolt and cork gasket around the cover edge, the concave cam follower covers (front cover with canister) 1098cc (Pt Nos: 12A1212/12H941) uses the neoprene washer and cup washer for the bolt and a neoprene gasket around the cover edge.
I have never had trouble with either type of cover/gaskets when fitted correctly.

[whyperion]

Thanks , I am trying to avoid replacing the rubber side cover gasket even though it is split - a nice vertical at about 6 o'clock, it seems to be nipping up well.

[les]

Why would you risk using a split gasket? Unless of course you're looking for something to do later!

[IslipMinor]

The plastic cap with gauze is the result of very muddled thinking - don't use it unless you like breathing oil fumes

Yes I agree - the vented oil filler cap is used so that filtered fresh air passes through it INTO the crankcase, not OUT of it!

It is only used if you have either the PCV or direct carburettor connection to the tappet cover oil separator; the correct filler cap is the vented one. Using the non-vented one is very likely to cause excess oil consumption, as the crankcase ventilation system tries to draw in fresh air, but cannot, so sucks in oil instead - not a good idea at all.

[bmcecosse]

For goodness sake - fit a new gasket on the side cover!

[Declan_Burns]

The rubber side cover seals on the market are a terrible fit. We have designed (CAD) and tested new ones and have already commissioned a batch of proper fitting water jet cut NBR seals for the side covers and for the rocker cover. They will be available quite soon. I am also currently working on the tooling to injection mould new quality trunnion seals that won't perish after a year like the one's currently available.

Maybe I should start a separate thread on this to inform everybody.
Regards
Declan

[whyperion]

Small Ad in Minor Matters, meanwhile I'll have 4

(keeping the iffy one only as I dont think its worth getting a couple on their own with postage, as I a just going to get the engine running first, then I will do a swap over if I see problems.)

[les]

Of course it does mean doing the job twice, something normally to avoid!

[whyperion]

err. one bolt to undo. redo and replace gasket as and when. Its been split for xxx years I presume. easier for me to keep all bits on the engine rather than risk losing them on the concrete flooring,

[les]

Fair enough, your decision, doubt you'd lose one bolt on the floor though!