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[Charlie]

Hi Marten. Sorry to hear of your oil leaks, my 1951 G2 had similar problems after a full rebuild and I am gradually getting it sorted.
For a dry sump engine I think your priority must be to ensure the oil level in the crankcase is not too high. So check scavenge side oil ways to make sure they are not blocked and make sure the scavenge pump / timing case surfaces are well lapped in.
I also had problems with blow by as a result of some dodgy piston rings, unfortunately the only way I could find this was by stripping the top end, let's hope you don't need to go there!
Cheers
Peter

[binary]

You said that, yesterday I took the primary case off and removed the reed valves in the breather, and that it is basically a hole out from the crank shaft?. This sounds like it breathes through a hole in the drive shaft of the crank. Some pictures would be a help.

[Citrus]

The models pre WW2 did not have the breather into the primary and just had a very small slot at the back of the crankcases and still managed to work OK - although the factory obviously decided further breathing methods were needed and were introduced later.
In the ideal world, the pressure will be pushed out when the piston comes down the first time, then if a one way valve is fitted (as per duck bill or reed), there would be a vacuum in the crankcase as the piston is up the cylinder. The result is that the pressure in the crankcase would always be at atmosphere or less - therefore not pushing oil out. With no one way valve- there is a constant suck/blow thing happening and some oil will be pushed out along with air. The amount of oil - will be defendant on the amount there to push out.
As suggested be other posts - I would be checking the oil pick ups and that the pump is working OK. As the return pump is twice the capacity of the feed - there should not be much oil in the crankcase.
I have pre war models - with no reasonable breathers - one is run on the race track - and there is basically no oil leak (and the return oil pump on those is the same capacity as the feed) - so I suggest the breathe is not the issue

[Alan R]

Hello MARTEN--------Have another read of SIMON's entry....I recently helped re-build a model G and that "Triangular" part is the engine breather itself....Inside it is a disc valve that MUST be free to move to allow the crankcase pressure to be kept at a minimum....As others have mentioned the oil tank is a separate item and the engine is a DRY-SUMP unit so there is NEVER an "Oil Level" to be measured in the crankcase...If there is then your scavanging system is at fault somewhere...A breather pipe fitted to the rear rocker cover can help and can be discreetly routed out of sight...

[PeteF]

Just to clarify something re breathers.
Later Indian iron barreled models breath via the oil "tank". There's a hole in the back of the crankcase through to the oil tank then a spigot on the top.
Older models don't do it like this so you can't vent the crankcase via the oil tank.
What you CAN relieve via the oil tank is excessive pressure in the rocker boxes caused by faulty valve guides etc.
This possibly causes confusion.

[Gwilly]

Has anyone mentioned wet sumping?

How much oil collects in the sump overnight?

Blow by will certainly pressurise the crankcase but will also give pressure to the timing case if the cork oil seal has broken up on the quill..

Did the 51 have a bronze bushing on the timing side crank? oil will flow in from the timing case and air pressure may blow out and increase pressure in the timing case..
Just a thought if the normal primary side breather is intact and operational..

[MartenLarsson]

binary: I did try leaving the pipe open, took the "discs" out, so there is just an open hole from the crankshaft to the atmosphere. It made a little difference, it doesnt leak out of everywhere now, just the timing chest/magdyno surface. I also tried riding with the oil cap off, it made no difference. Bullet Whisperer: Hmm, this oil cap seems like a mystery.. so the is no "riding" and "transport" position. This seems more right to me.. Charlie: Yes it is really annoying with all the oil unfortunatly... How to check the oil level? I removed all the oil filled it with -2 liters of oil like the manual says, that has to be the right level? The pumps seem to be in working order, all the hole i blow in there is air comming out the other end, and the pumps seem to be making vaccum when blocking the two middle ports with my thumb. I do think my rings are bad, the gap is way bigger than what it said in the handbook that i have, it should be -0.2mm to -0.4mm and the two top rings are like rhougly 0.8-1.0 mm.... Can this blowby be the source of my problem perhaps? Stripping the top end is no problem, the easiest bike by far to do it on
Citrus: So it should be a vaccum in the crankcase? Seems logical, i ordered duckbills for the breather pipe. maybe that will help the situation? In addition when i "drain" the sump, there is no oil coming out, just a few drips of oil. And also no blue smoke from the exhaust upon startup. Alan R: Maybe the gasket is distructing them from moving??? I will take a look on that. There is like i said never any oil in the "sump" when draining. And the pump seems to be working, pumping oil then air out to the "oil tank" underneath the oil cap. Gwilly: No oil in the sump, no smoke when starting. I replaced the cork seal (it was not there when i bought the bike, but the bronze bush... i dont know if it has it? Can i find out? Can air (crankcase preassure) seep out of the oil feed and to the timing chest? Lastly, i truly appreciate all the help!!! It is wonderful! I also will make a link to my dropbox, with pictures of the "breather" and the felt seal by the timing chest/magdyno mating surface... is this correctly mounted? I show how it is mounted with all the parts that i have on the picture with the timing gear. Dropbox link: https://www.dropbox.com/sh/lfbcr5h955ye ... lyqta?dl=0 //MÃ¥rten from sweden

[MartenLarsson]

Sorry for the hard to read text, it is very hard to arrange text in this forum....

[PeteF]

How to check the oil level? There should be a dipstick on the filler cap.

[Caboose]

Hi Marten,

Perhaps this will help when composing text on this site

http://gpoclocksystems.byethost22.com/m ... empt=1&i=1

Thanks to Scalyback for this.

REgards Dick.