Gregory Bender

Breather box - a look inside

Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models


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Okay, armed with the knowledge of those who have gone before me, and a little wariness on my part, I set out to disable the flapper valve and replace it with the ball valve. Here's my tale...

I removed the breather and had a look up the pipes...the largest diameter pipe is the one that contains the flapper valve. I checked it with a screwdriver and it seemed to work fine. I blew in it and it also seemed to work just fine. But, says me, I've got this nifty new ball valve just begging to be installed. So, out comes a hammer and screwdriver and I easily disable the old spring loaded flapper valve.

As I look inside, I can see the spring that held the flapper valve closed. I tip the breather upside down and the spring falls into my hand. Easy.

Now for the flapper is very similar to a fender washer and is larger in diameter than any of the pipes. There was nothing holding it in place and is now freely rattling about the breather as I shake it. I really need to get it out of there?

I lie down on my back on the garage floor with the breather in one hand and a flashlight in another hand. I start rattling and shaking the breather and, low and behold, I can get the flapper to block pipes.

I'm really not concerned about the large inlet pipe, as incoming air pressure will simply move the flapper out of the way. Furthermore, the inlet pipe sticks up above the base of the breather - so I doubt it would ever get popped on top of there.

But, the smallest pipe - the oil return line - is flush with the bottom of the breather. I can easily rattle the breather around and get the small pipe completely blocked. This would be disastrous on the road as all of the oil pumped into the breather would be expelled to the a hurry. This may not be likely, but it certainly could happen.

I try - in vane - to remove the flapper. I just can't get a good grip on it with any of my needle nose pliers. Plus, it's pretty thick metal (like a washer) and would be very difficult to bend and then pull out.

At this point I'm pretty much convinced that I've just trashed my breather. So, I do want any curious loop-o-phile would do. I cut the breather open with a hacksaw and take a look inside. :>

Photo courtesy of Gregory Bender.

Photo courtesy of Gregory Bender.

Photo courtesy of Gregory Bender.

Photo courtesy of Gregory Bender.

Photo courtesy of Gregory Bender.

Photo courtesy of Gregory Bender.