Moto guzzi le mans 1 gearbox breather pipe position

[gil]

Hello Again ...........
A further question regarding my ongoing Le Mans 1 restoration.
This time I am perplexed about the 'correct location' of the gearbox breather pipe .

The pipe that I purchased is fairly long and would allow the pipe to be fitted in different methods/places .
Referring to the parts diagram ,firstly we have bracket n0 66 which fits inside the battery housing ,I know for certain that the pipe fits here ...However  From this bracket onwards I am mystified ............
Does the pipe simply bend downwards and poke out somewhere below ,descending vertically (maybe tied with a cable tie )? OR (and this seems more logical ), continue  ,along the rear frame top member under the rear mudguard and held in position by bracket N0 20.
If option 2 is not correct ,what is the purpose of no20 bracket ?

Thanks for replies and any pics
 










 

[guzzisteve]

The hose goes up to the bracket in battery box(behind rubber bumper) and stops maybe couple inches behind, no other bracket for it. The other bracket you speak of may be for wiring.

[Stevex]

I have routed mine up to the front of the V and then back along the spine of the frame to the front of the battery box into a small collector bottle.
From recollection it needs the upwards trajectory to prevent loss of gearbox oil.
I've never had any oil get into the collector but it allows me to keep the bike tidy. i.e. not run the pipe to the back of the bike like you have.

[Dukedesmo]

Mine goes up by the battery, under the tool tray and exits down between the RH footrest and the driveshaft. Never had any oil exiting though it did come off at the gearbox end once (there was no hose clip fitted) at which time it did make an oily mess, so some height is definitely needed.   

[gil]

This seems to confirm that option 2 -with the pipe running  along the frame and exiting near the taillight ,is not correct ................
So does anyone know what bracket n0 20 is used for ?

[1down5up]

This seems to confirm that option 2 -with the pipe running  along the frame and exiting near the taillight ,is not correct ................
So does anyone know what bracket n0 20 is used for ?

Tail light and blinker wires from memory.

[John A]

They never push oil out if everything is normal. As long as they are vertical first up a few inches,then down to prevent water intrusion, it’s fine wherever you put it.

[HPRifleman]

This thread got me thinking so I took a look at how this hose is routed on my '78.

On mine, the hose comes out of the breather on the left side of the gearbox. It curves upward in front of the battery and terminates just behind the front edge of the right side cover. Just above the right carburetor air filter (mine has filters instead of velocity stacks). In other words, the hose runs across the bike rather than along its length.

Removing the left side cover reveals bracket #20 mounted in the same location as in Gil's photo, but this bracket has nothing routed through it.

[1down5up]

I'm fairly certain (though not positive) hat the 850 Le mans and Mk2 had the gearbox breather incorporated into the shift detent further towards the front of the box, and that from the lemans 3 they moved it to the rear cover due to oil spinning off 3rd (??) gear and forcing its way up the hose on some occasions.

[Stevex]

I'm fairly certain (though not positive) hat the 850 Le mans and Mk2 had the gearbox breather incorporated into the shift detent further towards the front of the box, and that from the lemans 3 they moved it to the rear cover due to oil spinning off 3rd (??) gear and forcing its way up the hose on some occasions.

That maybe why the breather pipe has to be routed up (to the spine frame) before coming back down to where ever.

[gil]

Some remarks >
Replying to HPRIFLEMAN.......
You are confusing bracket 66 and 20 -
N0 66 is the bracket in the battery compartment (on my image circled in red ).

As for bracket 20, I still have no idea of it's purpose ,so I haven't fitted it .
1UP AND 5 DOWN'S suggestion does not seem to work out either , as rear wiring can only fit neatly on the wrong side of the bracket .

Anyway after evaluating the various replies I have decided to go with DUKEDESMO's, leaving some length on the pipe.

Thanks for all the reply's and interest ...........

[lazlokovacs]

hope you get it figured out, that is one spanking clean Lemans by the way congrats!!!

and in the best colour no less

[1down5up]

Not sure my comment is the one your referring to but no worries, in the end some of this stuff doesn't actually matter this much, as long as the Breather goes somewhere and doesn't leak oil it's job is complete.

Some remarks >
Replying to HPRIFLEMAN.......
You are confusing bracket 66 and 20 -
N0 66 is the bracket in the battery compartment (on my image circled in red ).

As for bracket 20, I still have no idea of it's purpose ,so I haven't fitted it .
1UP AND 5 DOWN'S suggestion does not seem to work out either , as rear wiring can only fit neatly on the wrong side of the bracket .

Anyway after evaluating the various replies I have decided to go with DUKEDESMO's, leaving some length on the pipe.

Thanks for all the reply's and interest ...........