canisterectomy

[revperry]

What's a canisterectomy? Why should I do it? Why couldn't I find a thread in the search area? Thanks.

 

revperry

[Joe Frickin' Friday]

What's a canisterectomy? Why should I do it? Why couldn't I find a thread in the search area? Thanks.

 

A cannisterectomy is the removal of the evaporative emissions recovery cannister - the 12-inch long, 3-inch diameter black cylinder hidden behind the right sidecase. The cannister is filled with activated charcoal pellets which collect fuel vapors from the tank as the tank "breathes" during heat cycles, and then feed those fumes to the engine's intake system to be combusted, rather than venting them to atmosphere where they would contribute to smog.

 

Some people have reported problems with the cannister becoming clogged, causing tank breathing problems (tank ends up building pressure or vacuum, which it ought not do). Others have reported problems with charcoal being washed from the cannister into the intake system. These are the main motives for removal. This is emissions-related equipment, so depending on where you live, if your bike is subject to annual inspection removal may cause problems. Removal also will result in higher hydrocarbon emissions from your vehicle; depending on your personal philosophy, removal may cause problems in this regard, too.

 

Most people have not had problems with the cannister. Mine seems to be working fine after 110K miles; maybe the NOS sticker I put on it helps.

 

I don't know why you had trouble finding threads. I'm sure there has been discussion in recent months. Look in the support forum for a "sticky" thread on how to use the search function.

[JonathanE]

You can learn everything you need to know over at the Internet BMW Riders' web site. Enjoy

[revperry]

Thanks, Mitch. I'm a brand new owner ('02 R1150R) so this forum is a wealth of info for me.

 

revperry

[Ken H.]

Why should I do it?

You shouldn't.

 

Charcoal cannisters as a pollution control device have been used successfully for many, many years now, including on BMW bikes. There is no evidence of greater failure of them than any other part of the bike. And if it does fail, for the benefit of all of our air quality, it should be repaired / replaced, not removed.

 

In reality it's just one of those things that BMW owners love to play with (removing it) that serves no purpose, and is harmful to the environment to boot.

[wolcott]

I'm pretty sure that when I had my '99 RT in the shop for throttle cables & choke cable changes, that the BMW tech told me that if I ever let the bike fall over on it's side I should replace the canister. Does this sound correct?

[Bob Palin]

Doesn't sound right to me, are you sure he didn't say to check it, they can get bent in and rub on the tyre.

[Ken H.]

Because it collects fumes from the fuel tank, there is probably some scenario one could dream up where during a fall the angles where just right that a small amount raw fuel could get into the vent line and eventually be drawn into the canister. I'm sure it would just evaporate there though (after all there is a small air flow through it, and that's what it's for) and it would be a non-event.

 

But then there are a lot of potential scenarios for a lot of things one could dream up.

[KMG_365]

There is no evidence of greater failure of them than any other part of the bike.

Well don't tell Ken, but I've removed about a dozen of these things and on about half of them the lines were clogged at least somewhat to full occlusion. This can happen very easily actually from either overfilling (fixed somewhat on the 1150 when they put the flange in the filler port that keep you from easily overfilling it) or dropping the bike--especially with a full tank. The cannister is meant for vapors only and when liquid gas enters the cannister it washes the charcoal back down the exit line and this clogs the flow and restricts the venting of the tank.

 

If your cannister is still in place and you notice a sucking sound when you open the filler cap, yours is plugging up. Eventually, the obstruction will become complete, but even with a partial obstruction at WOT the FI's will ask for more fuel than the tank can provide due to the vacuum and the sides of the tank will be drawn in. When this happens the weak link is the dip tube that carries the fuel level float inside it. When your RID fails to read over the entire range or is stuck on a certain level regardless of fuel present (usually around 4-6 bars) the dip tube has been crushed and is pinning the float. The fix is easy: drain the gas and remove the tank. Remove the dip tube from the top of the tank and find the dent in the dip tube:

 

 

 

 

 

Drill a hole (or two) opposite the dent and use a 3mm T-handle or other such instrument to pop the tube back into shape (observe all common sense cautions regarding power tools and gasoline vapors! ).

 

 

As good as new!

 

 

But like I said: don't tell Ken!

[Ken H.]

But like I said: don't tell Ken!

Well like I said, I still think that if the canister is failed, the right ecological thing to do is to replace it, not just chuck it.

 

Got to keep my tree hugger reputation in tack you know.

[wolcott]

Doesn't sound right to me, are you sure he didn't say to check it, they can get bent in and rub on the tyre.

 

In response to killer's question: yes, i am pretty sure that is what the BMW tech told me- to replace it. He is a master BMW tech supposedly working on BMW's for over 20 years at Haps BMW in Sarasota, Florida. This was just after I had bought my bike. The choke cable hung up way out of adjustment and I noticed in the Haynes manual that at 18k all throttle cables should be replaced. When i seen what it entailed, I decided to let them do it since it would need a TB sync anyhow. The canister question came about since I am a small guy to begin with, had just finished chemo & radiation therapy and the tech was worried about me letting the bike fall over. He did make me laugh however, when he praised my dedication to riding while going through those dang cancer treatments. Thanks.