Air filter

[Dizerens5]

Once again I'm asking for some help....if you have an early R65 (mine is 1979) you will know that there is a breather hose fixed to the left side air filter cover, making the cover impossible to remove --- apparently. A bit of research told me the answer, remove fuel tank, remove starter motor cover and detach the breather hose from inside. Fine. Except that the wiring harness under the tank makes it impossible to  raise the starter cover enough to remove it, and even if I cut the ties fixing the wiring to the frame, it looks as though there would not be enough slack anyway. Should I try all the same? I don't want to wreck the relays or tear out any wiring. Or is there an easy way out? Help appreciated! thanks.

[Barry]

Perhaps not impossible but most certainly a PITA. That breather tube is just a tight push fit in the cover. I don't remember it being secured any other way. I think I managed with lubrication and brute force gentle persuasion pulling back at the angle that the tube goes through the hole. Once it moves a bit things get easier and you can see better what's happening.  What I know I did do was clean and polish the hole even opening it up a little with some fine abrasive paper. It was much easier the 2nd time.

If you are going the starter cover route,  I remove the coils first and the cover will then just about rotate off ok without disturbing anything else.

[Lucky_Lou]

Mines a 79 r65 the clam shell covers come of easily enough ...as Barry says clean/polish the inlet hole and lube the breather pipe when assembling the locking nuts on the inside (10mm i think) dont need to be too tight allowing the cover to slide into the locator leave the outer hoses off so you can guide the long locking screw into internal thread.
Personally i wouldn't blank the breather pipe off.
Lou

[Rob Valdez 79 R65]

I don't think the starter cover is meant to be removed until the air filter cover is removed, first......

I hated those two hoses running into both sides of the clam shell, after the 'T' fitting.
I finally threw it all out and ran it to atmosphere.
It stopped the oil from dripping on my left boot from the carburetor, too!

My first attempt to reroute was rather clumsy - I sent it out the air intake in the starter cover, and down the left side of the bike to the swingarm.

Later, (click for pictures) I drilled a hole in the right half of the clam shell and routed the hose out that way.  I am in the middle of rebuilding my bike, and some of the details will have changed from what you see in those photos.

I also plugged the two holes in the clam shell halves so no unfiltered air could enter the carbs.  I used rubber stoppers from the hardware store, and cut them down to fit.


You could also go to the auto parts store, and buy some spray silicone lube.  That makes it easier to get the rubber hoses through the alum. castings.


Or, you could buy one of these from any dealer (or Huckeys, since he provided the picture!) and just run the vent to the right side of the engine:



http://www.bmwhucky.com/007511.html
scroll down half-way

[Barry]

Rob

Did you get any noticeable running benefit from your mod.  I recall reading somewhere that introducing oil into the combustion chamber reduces max. power output. On the other hand it seems to work OK for 2 strokes.

[montmil]

My 81 and 83 R65s have a similar crankcase vent hose as the one pictured in Rob's post.

The difference on my bikes is the angled cut on the end of the pictured vent hose is square cut and attaches to a nylon-ish connector that continues into the airbox and a 'T' fitting.

From the 'T', there are hoses/tubes that ultimately end up puking c'case blow-by into the hard plastic airbox-to-carb tubes just upstream from the carbs. Guess we can blame CARB for this "green" performance item.

Monte

[Rob Valdez 79 R65]

Rob

Did you get any noticeable running benefit from your mod.  I recall reading somewhere that introducing oil into the combustion chamber reduces max. power output. On the other hand it seems to work OK for 2 strokes.

None that I could tell.  But that was like 1984 when I did it, or something like that.

[Dizerens5]

Thanks everyone. I'll have another try. The filter probably hasn't been replaced for years, judging by its greasy condition I think I can guess why!

[Rob Valdez 79 R65]

It is possible that one of the hoses has gotten hard and cracked, and you are getting some of the oil mist into the starter area, and the inside of the airbox.