1950 nh

[BrianSteytler]

am i right in saying the chrome metal clutch dome has the small (1/2" or so) hole in the bottom of it as an overflow? there is no screw thread that i can see and anyway the thickness would not support a screw but maybe a grommet??

i topped up the chaincase to the fill screw and the gearbox with grease/oil mix but as i had no idea how much was in there already i figured an extra couple of ounces was better than it possible being low. anyway when i started it up a load of when looks like the gearbox fluid came pouring out although this has now settled down to an occasional drip!!...

or am i missing something??

[chris.shearwood]

Hello Brian,
The chaincase should be filled with just enough oil to contact the bottom run of the chain. If you fill it up to the level screw you have a bit too much oil, if you fill it up to where the large plug screws in (fill screw???) you have way too much.
Regards, Chris

[brenton.roy]

Hi Brian,
It's fairly likely that the oil will keep coming from your primary case for a bit yet..
The best level is so that the chain is just touching the oil. This is below the drain plug.
Too much oil tends to be spat out.
It might be worth emptying the case back to at least the bottom of the drain plug.
I'm not sure from your post where the "gearbox fluid" was dripping from or whether you topped up the chaincase with oil or grease/oil.
Gearbox grease/oil would probably leak from around the sprocket (behind the cases).
If it's coming from the hole in the steel clutch cover, you may need to take the cover off and degrease around the clutch.
Good luck!

[BrianSteytler]

i didnt really explain myself well enough. i filled it to the 'level screw' but some still came out the open hole in the bottom of the clutch housing - i guess it was already about right and i overfilled it!!.

i know it was a bit of a stupid notion about the gearbox oil (which is what i was begining to think this oil was) but as the oil i put in was a deep engine oil sort of colour but what dripped out was a very light brown almost runny cream colour i did wonder if it was the oil/grease mix maybe comming from the box via a worn shaft.

anyway its now stopped dripping and all seems to be ok so its back out asap.

[brenton.roy]

Hi Brian,
There's nothing stupid.. We've all overfilled the primary. It's a pain in the arse.
The change in colour is due to your chain whipping the oil up - and possibly a small amount of water in the primary. This would be either from condensation or washing.
Problem solved!
The only way I've been able to get the oil to a level I'm comfortable with is to get a torch and look. If there's an easy way, perhaps someone will tell us!
Brenton

[nevhunter]

Run the engine with the filler off and add oil till the chain can be seen picking it up. It drops down from the top run of the chain, as a fine mist/spray. You will be lucky if you don't get some oil leak from the chaincase. regardless. Nev

[john.nash]

I'm with Nev and Brenton.

The "oil level" screw is too high.
If you fill it this level, then it comes behind the back of the clutch as there is a nice big hole there. The chain just whips it up.

Preferably just fill to "chain just kissing the oil" level

The other method is to fill where you like (i.e. the oil level screw) and then put an oil drain container underneath the clutch area.
Start the bike and let it idle and "self level" for a while.

To check if you have enough oil, then just put your finger in and touch the (non-running) chain - if you get "oily finger" then you're good.
Or, as Nev says, take off the inspection cover when the bike is running to spot the oil spatter.

An oil tight bike is possible; I am informed.
Something that doesn't appear possible for me though .... for any length of time..

[brenton.roy]

An oil tight bike is possible; I am informed.
Something that doesn't appear possible for me though .... for any length of time..

Me either. It's great to have no oil leaks, but it's always temporary. First decent long run.
Maybe with sealed mains and better breathers..
Oh well.

[Simon.Gardiner]

My BM has got beautiful and very sophisticated rubber O-rings all over the engine joints. I always put it together oh so very carefully. And it still leaks. (OK, so it takes more than the first long run but I no longer lose anysleep over the drips from the Ariel )