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[jaybie]

Adrian,

Huge thanks! So assuming it's not a tank leak it sounds like it's nothing to worry about. I've certainly not seem much smoke.



Just so I understand fully, and I'm sorry to be a pain, on the parts diagram item 27 stops the oil from the rear gear pump entering the timing chest instead of the crankshaft. The oil travels down a route in the timing chest cover itself?

When I start the machine, the oil in the sump must get whipped up by the crank, and make its way via the tank/crank breather into the oil tank and thence up the breather pipe?

My bike has a Bunn breather fitted and I'm planning to reroute the tank breather hose so it's more vertical, to give the oil a chance to run back into the tank rather than out onto the floor. There's also a smidge of oil in the timing chest (inlet) breather hose so when I eventually have the timing cover off I will replace the duckbill that's inside.


Cheers,

JB

[jaybie]

To help clarify Stinky's pic, here is a 1994 Bullet crankcase half showing a drilling between case and oil compartment

Where on the dipstick is this hole level with?

Cheers,

JB

[Allanfox]

Hi, it is well above any dipstick marks, around halfway down the dipstick if I remember correctly.

[Allanfox]

Just so I understand fully, and I'm sorry to be a pain, on the parts diagram item 27 stops the oil from the rear gear pump entering the timing chest instead of the crankshaft. The oil travels down a route in the timing chest cover itself?

Yes

[Adrian]

It's been a few years since the Bunn breather kits were on sale. What you describe as the breather pipe on the back of the timing chest is actually the oil return pipe from the catch-can, as originally supplied by the factory. The duckbill inside the timing chest is pretty useless as a non-return valve, doesn't the Bunn kit have its own non-return valve for this as well as one for the main breather pipe? Do you still have the catch-can gubbins fitted?

A.

[jaybie]

It's been a few years since the Bunn breather kits were on sale. What you describe as the breather pipe on the back of the timing chest is actually the oil return pipe from the catch-can, as originally supplied by the factory. The duckbill inside the timing chest is pretty useless as a non-return valve, doesn't the Bunn kit have its own non-return valve for this as well as one for the main breather pipe? Do you still have the catch-can gubbins fitted?

A.

No catch can. I have a hose allowing air into the timing chest with a one-way valve (in) and an air filter, and I have a hose leading from the oil tank with a one-way valve (out) and an open end.

I'm thinking I'll need something to catch the oil and either let it run back in the oil tank breather or perhaps use one of the oil tank filler neck banjos that our hosts do. I'll try a long vertical hose run first (with careful attention to not overfilling with oil) then move onto more complicated solutions if that fails. How much breeze is there running through the breathers?

JB

[Adrian]

Say there's 499cc of air/crankcase gases (½ lire) being displaced on every downward stroke of the piston. Multiply that by your engine's RPM figure, e.g. a constant 4000 rpm, you'll get an idea.

As I have already posted, the Electra-X just needs a very simple assembly of ⅜" bore hose ran out to the back of the bike, with a non-return valve inserted in the hose run fairly near the breather exit from the oil tank. You can block off the unused oil return to the timing chest, the breather from the primary chaincase doesn't seem to do a lot, either.

A.

[jaybie]

That's a fair breeze! In fact as I turn the engine over slowly I can hear the valves opening & closing. This is a job for another day, once I've stopped the oil blowing out (with reference to your other threads regarding this). I'm aiming for 1/2 way between the marks as a max once it's run up for a bit.

Thanks again,

JB

[Allanfox]

I have just been through the same train of thought with mine and did suffer from a very oily bike if even filled anywhere above the bottom of the dipstick, luckily my crankcase still had the cast spigot by the engine number, so while I had it stripped I drilled it out and reinstated it as the main breather like on old bullets. Fitted a Hitchcock kit and seemed to be working fine until I have had to strip the top end looking for a fault (again!) However looks tidy (just the pipes you can see), no oil externally (well mist on chain) and all being returned to the tank!

Still testing but seems fine so far

[windmill john]

Blimey, some of you have such shiny bikes!
Whilst not proud of mine being dirty, I ride all year, so don’t want to be a slave to cleaning.
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