epa system

[Air4Life]

I'm curious as to how many people do away with the environmental apparatus in one form or the other?

to date, mine is intact.

I spoke with someone who is known to be knowledgeable, and he strongly recommend doing this.

[Bob_Roller]

There is nothing to gain by removing it .

The only problem it will cause, is if the rubber lines from the carb to the valves develop a leak, or if one of the diaphragms in the valves fail .

I had a diaphragm fail and couldn't figure out where my vacuum leak was .

I then removed the system and have not seen any difference in the performance or any engine running issues, it's been off of the bike since '83 .

[montmil]

Yanked it. Cleans up the visual. No performance difference, except for the weight loss.

[flybot]

I ripped the system out during my rebuild. Added complexity, no performance gain. Bubye!

[Barry]

I'd take the system out just to lose a little weight.

Less is more



Come to think of it isn't there a better reason to remove it. Air injection is reckoned to make the exhaust valve run a little hotter and that's definitely something you can do without.

[Air4Life]

Seems like a strong enough consensus is built up here for me.  Yes, he mentioned all the things you folks mentioned.  The one tantalizing reason was that the exhaust valve received added heat from the added oxygen. Though, his emphasis on the heat was a bit stronger than yours Barry. But that may only be my interpretation of what he said.

I'm sure you've run through these question countless times.  I appreciate all your patience.
  
Thank y'all.

[Barry]

Yes perhaps I shouldn't have used the words a "little hotter"  Point is that any increase in the exhaust valve temperature is a very bad thing. Makes you wonder if the reputation for valve heads coming off isn't substantially down to this air injection and for me that would be the stand out reason to get rid of it.

Any way you sound convinced.

[montmil]

This whole "air injection" system was added by BMW to meet the California Air Resource Board, CARB, standards. Otherwise, the BMW line could not be sold in that state. We all inherited the crap and occasional related reliability issues of the exhaust valves.

Even today, gasoline-powered lawn mowers, power generators, weed whackers, leaf blowers, chain saws, ad infinitum, sold in California must meet CARB standards. Ckeck Sears, Lowes, Home Depot, etc and you'll find yard implement specs that state,"Not for sale in California". You must buy the higher priced Cali items... with, of course, the BMW-ish air system fitted.

And just try dropping a new Chevy 350SB crate motor, with a carburetor, into your early Chevrolet project car. Good luck fighting the DVM on that one. You'll need a few weeks off work dedicated to just standing in line.
[smiley=wall.gif]

[MR.E]

Where's the EPA on the bike??
Or is it just a US r65 thing??


Thanks

[montmil]

Where's the EPA on the bike?

Unsure what you're asking. Are you inquiring as to the US Environmental Protection Agency's "position or governmental stance" on the bike?

[suecanada]

I think Mr. E wants to know where physically this environemtnal apparatus actually is on the bike. Referring to all the tubing from the air box, vaccum thingy on carb into cylinder etc. I can hardly remember it but I took it off too.

[Barry]

Just a North American thing.  Air injection was never fitted to UK bikes.

[montmil]

Really wasn't the EPA that mandated the Pulse Air System for the BMW motorcycles. We in the USofA can thank the State of California. Thank isn't really the word I'm thinking of.

Here's an excellent photo essay and parts requirements for removal of and plugging the BMW Pulse Air System.

http://www.webbikeworld.com/Motorcycle-technical-articles/pulse-air/

[MR.E]

looks like an EGR setup.
To recirculate the exhaust gasses etc.

Thanks

[montmil]

looks like an EGR setup.
To recirculate the exhaust gasses etc.

Thanks

No.

The system "injected" a charge of fresh air into the exhaust port just above the exhaust valve itself. This fresh air, combined with the remnants of the flaming fuel burn, basically, re-ignited the fuel charge for a second time as it passed through the exhaust valve and into the mufflers. This double whammy of fire and heat was what helped create the dreaded exhaust vale head failures and the valve's recession.

A band-aid to sooth one state affected the entire nation. Now days, most all new motorcycles are fitted with some sort of catalytic converter which is Federally mandated.

I often wonder how much air pollution motorcycles contribute versus automobiles and trucks. Recip aircraft engines are exempted from emission control devices as these aircraft are considered to be not a contributing factor to air pollution. Plus, they need to burn leaded avgas to maintain top end lubrication in the valve train. General Aviation is a very minor player in the clean air acts imposed on manufacturers by a one-size fits all gubmint. I believe motorcycles should also be exempted.

Share with me your thoughts.