Breather Check....

Ducdude

Well Known and Active Forum User
VOC Member
I know there are many things left to put right on my 52 Shadow, but while I
have the week off from working on her I have been wondering....Is there a
good way to check to see if I have the breather timed properly? I ask as I
always get a good bit (1-3oz) of oil out of the breather when running her in
the drive way for 3-5 mins or so...

I matched the gear markings up as per the books/manuals/handbooks/tech
sheets etc. If there was a fairly simple way just to confirm I have the
bugger set properly I would be very appreciative to learn it....

If it is correct I may start to play wit the idea of relocating/re-running
the hose to limit the drippings...First things first, is it correct now?

Much thanks Gents,
Eric
 

Albervin

Well Known and Active Forum User
VOC Member
Vincents tend to breath heavily at idle but at 25-30ml/min you are going to empty the tank quickly. Check compression. If there is a lot of blow by past the rings then you can blow a lot of oil out the breather. What is the oil level in the sump when you fire up? What is the return rate of oil to the tank like? Should be similar to a 70 year old man with moderate prostate hyperplasia/hypertrophy.... i.e. a steady dribble with the occasional spurt.
 

Ducdude

Well Known and Active Forum User
VOC Member
Thanks Albervin,

I have 151psi front and 153-155psi rear and getting better every day.. I started at 60 and 60 psi......:-( this bike sat for 40 years as you may recall.

The oil out of the breather does seem to be greater if I have oil in the sump but no matter if I drain the sump or not I still get a oil out of the breather.

The return rate of oil appears to be normal with a steady dribble at idle and good steady full pulses at higher RPMs. That is why I want to make sure I have the breather timed correctly.

Thanks,
Eric
 

stumpy lord

Well Known and Active Forum User
Non-VOC Member
Hi,
do you have a copy of Paul Richardsons book Vincent? In it on page115 it shows the the lay out of all the timing gears including the breather spindle and gearl. the slot in the spindle should face the magneto top stud , and the slot in the pinion should face seven o clock position. hope this helps.
norm.
 

Bracker1

Well Known and Active Forum User
VOC Member
Hi Eric, Worst thing to do is let the bike sit and idle for 3-5 minutes. You will wear out the lifters and cams. Get the bike riding for a good ten minutes and check the breather , should look like a puddle of latte. They all spit oil. Don't bother with the other breathers, the bike will work fine without the elephant tubes. The more you ride it the better it will run, until the next part breaks. It is quite a tough engine, don't worry about the oil. The oil keeps the rust away. See you at the International. Dan
 

timetraveller

Well Known and Active Forum User
VOC Member
There is a test you can do which only requires the spark plugs to be taken out and a piece of clean plastic tubing. Remember that the breather is meant to be open when the pistons are descending and closed when the pistons are rising.

1) Remove both plugs
2) Engage top gear and rotate engine by the rear wheel.
3) Using a screw driver or other thin metal rod determine when both front and rear pistons are near their upper positions, TDC.
4) Now take the piece of clean tubing and push over the outer part of the existing breather outlet tube and try to blow down the tube
5) Just before the pistons are near to TDC you should not be able to blow down the tube
6) Just after joint TDC you should be able to blow down the tube
7) You should be able to keep blowing down the tube until the pistons are near to their joint BDC
8) You should not be able to blow down the tube all the time the pistons are rising
9) Take a large hammer or spanner and apply it forcefully to anyone who suggests to you that this type of blow job is evidence of an unnatural relationship between you and your bike!
 

Howard

Well Known and Active Forum User
VOC Member
Just one question Timetraveller. Why do you need "clean" plastic tubing? Are you getting fussy in your old age?

H
 
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