Crankcase Breather Tubes

I have reinstalled my stock airboxes and purchased new breather tubes from Mikes. These tubes are very long. Can I simply cut them to fit the distance between the crankcase outlet and the standard airbox inlet pipes? I ask because I fear the extra length may be required to maintain some form of "pressure gradient" or other obscure mechanical necessity that inhibits the return passage of debris into the top of the case or vice versa. If I am being dumb, let me know but I don't want to cut them off, find I've screwed up and wait a month for replacements from Mikes to arrive in Oz.

Very easy to get caught up in the MikesXS as the only XS parts supplier. Geoff'sXS has the same parts sold out of Sydney..............And a piece of tubing from an Auto parts store will do the same job.............

I buy from Geoff's in preference to ordering from the States but, in this instance, I think I was trying to pack out an order of stuff that Geoff didn't have in stock. Your reminder is timely as I do tend to act before considering alternatives. So, Skull, can I shorten the 14" tubes without any consequences to their effectiveness - I assume they are simply a passage way for misted oil from the crankcase to the airbox and the shortest distance between two points etc..
Cheers

Hey Dave, I can't say i know a lot about the short or long of the tubes. From 76, (i believe), the hose was routed back through the air-box's. HERE is a good thread going on at the moment about this issue.

I kept it really simple, not wanting the crap going back in to the engine, drill a hole (left hand cover, close to the clutch cable entry point) the same O/D as the hose and you will have a nice chain oiler...I'll look for a picture or take one today for you Dave. I've done over 10,000 miles in a year like this and the fucker hasn't blown up yet

Mick

Edit: here's pic

Cut it to fit. The twin tubes from earlier models were shorter than the single tubes from the later models.

Thanks for those comments gentlemen. I will follow that thread for the next few days Skull to see if I can gain any further insights and I will try and route the tubes up between the airboxes first to see if that takes up any slack. If not, I think I will stop procrastinating and cut the tubes to fit as per WER's advice. Sorry Mick but I didn't make it clear that I have the dual breather tube set up. Thanks for that solution anyway - looks really neat and obviously serves the intended purpose. I know I could purchase a single breather outlet arrangement and adopt this method but I'd rather stick to the original layout. Frankly, the idea of drilling holes in the cases leaves me a little cool and is a procedure I would rather leave to you fellows with more nerve and experience than myself.
As usual, I have received the support I needed from this forum to approach this little job with some confidence.
Appreciated.

Mikes tubing wasn't made specifically for the XS650, it is for later models. Look at the item on his site and click the fit and fitment tab. I think the diameter just happens to match.

I buy their "bulk" breather hose (1 meter long) and just cut it to any length I need. It's cheaper that way.

Job sorted....another small step etc. Thanks all.

One small step for Dave , a giant leap for mankind !
.....
Bob........

True Bob. My '78 SE and I advance so slowly that I sometimes feel a little like Mick Collins must have felt while he watched Neil and Buzz bounce around on the moon - involved but somewhat dislocated. I find that these small successes provide me with an inordinate pleasure that compensates for my more expensive and regular screw ups and engaging with the forum is a welcome respite from sitting and staring at the thing whilst I wonder what the hell I am doing and whether I should have bought that 2010 Moto Guzzi V7. I guess that's part of what we are all involved in with these old motorcycles. Before I expire I will get this old lady back the road. Imagine the sense of achievement. My old man would be proud. But, "sutjes sutjes" as H. Rider Haggard misinterpreted in Afrikaan, "gently gently", one step at a time.
I appreciate your humour and encouragement.
Dave

Hay I had the same REVILATION when that monstrosity I call a 82'xs650 finally ran PROPERLY after fighting it for a constant Month...but I wasn't about to give up on the o'l girl ....I love bikes and it's Mine and there fore I will prevail !
I've had many motorcycle engines down to the last bolt appart but never had the trouble I had getting this beastie to run right....come to find out it was just the carburators.... and ME.... i took them off 3 times to do a thuro cleaning and only the last time was I successfull at the basic cleaning job!
talk about feeling OLD ! I mean yah it's been a few years but you don't forget your lifes work ! but these were a new breed to me the only thing even close were the carbs on a Honda 450cc about 25 years ago..... they sure gave me a run around ! but clean living and perserverance prevailed and I was victorious !
I pulled on the choke hit the starter and it made about 1/2 revolution and fired right up ! ON BOTH CYLINDERS ! i was never so glad to get a bike running in my life ! HAHAHAHAH ! i walked into the house and my wife said I hurd it ! and I exclamed YAH ! I finally got her running !!!
the rest was trivial getting her in perfect tune and all..... but it was a major triumph after not having a bike to fiddle with in the past 4 years !
I've felt like a fish out'a water ! .....
being on this site has been really good for me...it's got my grey matter working again I hadn't even realised how RUSTY i had became on things mechanical in the bike world..... the old saying ...if ya don't use it ya loose it ....Strikes me....and boy that is soooooo true.....
i'm 64 1/2 yrs old too young to die and too old to give a shit about much..... but I'm telling ya... dive into something and keep thinking or you will vegitate ! ....LOL
C ya !
Bob..........

David, good to see you again. I have sometimes thought that I'm not really very fond of what the vent tubes do to the inside of my air box, which is , turn them into an oily mess. I kind of like Micks idea of using that oil vapor to provide a free and constant lubricant to the chain , but like you I am reluctant to drill a hole in my nice shiny case.
I had an old Triumph that had a crankcase vent hose that must've been three feet long. The factory routed it along the edge of the rear fender and just vented it out to the open air, or to the front end of the car behind you! Haha
Here is a photo, and if you look close you can see the silver colored hose following the edge of the rear fender.

Hello Mailman. I have been following your All Balls Bearing Kit installation with some interest as it is on my own agenda. I have also been delighted with your successes and well deserved riding outings - had nothing concrete to offer so I just enjoyed the reading. That is a fabulous looking Bonnie and I love those bars. I have been ignoring the "rototiller" jibes as I kind of like the look of the SE's bars and wanted to maintain originality but those Bonnie bars could sway my resolve. Another possible month on the blocks if I succumb. Oh well, I'll probably live longer while she's in the shed.
As for spraying my engine oil over tailgating vehicles and jaywalking pedestrians, Mailman, I thought you were a rider of character. The idea, whilst tempting, would only add to the list of gauche behaviours I will have to explain when I ultimately do meet my maker. Mind you, this is my first XS so when I encounter that oily mess you have described in my shiny painted airbox, I may sing a different tune.
Regards

Michaelo said:

I kept it really simple, not wanting the crap going back in to the engine, drill a hole (left hand cover, close to the clutch cable entry point) the same O/D as the hose and you will have a nice chain oiler...I'll look for a picture or take one today for you Dave. I've done over 10,000 miles in a year like this and the fucker hasn't blown up yet

Mick

Edit: here's pic
View attachment 98565

Click to expand...

Mick, does your set-up keep you from actually having to oil your chain? I like it!

madjap said:

Mick, does your set-up keep you from actually having to oil your chain? I like it!

Click to expand...

My thoughts on this..........used engine oil is acidic, I wouldn't want that on my chain or my chain o rings. And then, most of what comes out of that breather should be moisture (H2O), condensation that has evaporated because of the heat of the engine and heat goes up with the moisture evaporated and out of the breather. I wouldn't want that moisture on my chain either.

Scott

mrtwowheel said:

My thoughts on this..........used engine oil is acidic, I wouldn't want that on my chain or my chain o rings. And then, most of what comes out of that breather should be moisture (H2O), condensation that has evaporated because of the heat of the engine and heat goes up with the moisture evaporated and out of the breather. I wouldn't want that moisture on my chain either.
Scott

Click to expand...

Hi Scott,
surely you exaggerate?
Your namesake ScottOiler works better than the engine's oily acidic damp breath but running the chain
with nothing on it means you dare not ever go riding in the rain?

And who wants regular oil on their chain anyway? It's not thick enough to stay there, it just flings off and makes a mess. Now, instead of possibly having one little oily area on the bike around the breather pipe outlet, you've got it splattered all over the place, lol.

5twins said:

And who wants regular oil on their chain anyway? It's not thick enough to stay there, it just flings off and makes a mess. Now, instead of possibly having one little oily area on the bike around the breather pipe outlet, you've got it splattered all over the place, lol.

Click to expand...

Hi 5twins,
while some oils fling off chains quicker than others they ALL fling off to a certain extent.
If you want a bike that stays clean you gotta buy a shaftie.