V35 oil lines

Hi, The rebuid continues, albeit slowly. I am constantly finding parts that are either missing or need replacing. There’s a scabby bit of plastic pipe running from the sump and is tied up and what I assume are breathers in the rocker covers are “blanked off” with plastic. Parts 32 and 39 on attached diagram seem to be what I need.
Do these connect to each other?

Thanks for looking.

Pipe 32 collects oil from airbox, and oil in airbox comes from those two pipes giving a breath to both heads. The rubber holding those two pipes together and connecting them to airbox perishes first and you can try to save it with thick layer of car window glue. You can see it here

listed for an unacceptable price, but perish is clearly visible.

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Thank you adamigo, most helpful. I have the airbox and the connector seems ok so may, if I can find the correct diameter rubber pipe, I can use it.
Alternatively, I have thought about using individual cone filters for each carb but then I’d have to find another way to connect the drain pipes to the return :thinking:

You mentioned part 39, did you mean part 29? :thinking:

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Definitely 29, don’t think there is a 39 :man_facepalming:

Cone filter is a big mess, carbs work totally different and you need to re-jet them, not an easy task. But doable, as you then buy a metal box doing the same job - collecting the oil. Like this one:

Anyway, hoses you’re after are quite thin-wall, and I was bit over-enthusiastic buying what Gutsibits offered - well, it was standard fuel thick-wall hose, but with correct OD it does the job, even if tight inside.

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Thanks Adamigo, I think I’ll stick with original setup then. Plenty of time as there’s a myriad of tasks and parts I need to source before I finally don my helmet and press the starter button.

Struggling with correct size to buy. Is it id/od=8mm/11mm?

This solution is not for the faint hearted
On my Monza (same breather layout as your V35) the two cylinder head breathers are routed down past the brake pedal to just below the sump and the return pipe to the sump is junked and the hole sealed off with a bolt and copper washer.
This effectively is how older Brit bikes used to vent to the air
This setup then allows you to get rid of the air box and fit cone filters but as mentioned by Adamigo it does involve rejetting but mine only had the main jet increased by 10% giving good running


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Thanks Chris, Would you happen to know the breather pipe dimensions?

I’ve just ordered a new sump pipe, part 32, from Gutsibits -about £11 - for my 1979 V50; rational being that the original appeared badly perished and I wonder whether also blocked as sone oil is draining from the rear airfilter section… main concern, however, being that if said perished pipe failed I could lose all the sump contents.

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I also added a jubilee clip to the soft Union where the two head pipes are linked into the base of the air filter as this was oozing oil… tightened up carefully in stages as I worried about crushing the plastic spur of the airbox. To be fair, it’s as tight as I dare and now just slightly oozing oil. I’m hoping that the new 32 pipe might finally resolve this.

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I’ve seen new parts from Italy,


My concern is how much brexit tax I’ll have to pay? Otherwise they look very reasonable even including p&p!

My Sump return landed today, £11.30 from Gutsibits… it’s on one of the middle pages under engine spares… I bought a couple of inlet rubbers and some new side panel grommet things and this lot added £4 postage to the Bill. I bet they have the cylinder head breathers too.

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Thanks, I’ll check them out :+1:

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Both head breather and return pipes ordered. Thanks for the info :+1:

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