Removing the Pulse Air Injection System

[pedrocasper]

I have a 1984 R100, in which I'd like to remove the Pulse Air Injection System (PAIS) and traditional airbox. I found the following article on internet riders.

http://www.ibmwr.org/r-tech/airheads/plug_fresh_air.shtml

I'd like to put K&N round/bullet type airfilters on the bike for a more traditional cafe look. My concern is the breather hoses and fittings. I like to run the breather hose into a nice catch can I will mount on the bike. I have done this on smaller displacement honda CBs that I race, but was wondering if anyone has done this on an airhead. I will still be using this bike as my street bike, so I don't want to really screw things up for pure asthetics and limited power gain.

 

[bikerfish1100]

i picked up a small K&N filter unit for exiting the oil breather hose into. Sorry, no pics.

 

[testinglogin]

You could simply remove the pule air system. You just need two plugs and some red loctite for where the tubes go into the heads (some dealers sell these) and then pull the rest of that useless system off. You'll also need rubber plugs for where the tubes go into the airbox... although you want to remove that box, so I guess you won't, after all.

I'd look to use something different than a K&N. I used to run them in my trucks, until many tests have shown how much extra dirt they let into your engine. I wonder if there is a paper filter you could use in place of the K&N so you have the look AND functionality?

 

[pedrocasper]

You could simply remove the pule air system. You just need two plugs and some red loctite for where the tubes go into the heads (some dealers sell these) and then pull the rest of that useless system off. You'll also need rubber plugs for where the tubes go into the airbox... although you want to remove that box, so I guess you won't, after all.

I'd look to use something different than a K&N. I used to run them in my trucks, until many tests have shown how much extra dirt they let into your engine. I wonder if there is a paper filter you could use in place of the K&N so you have the look AND functionality?

That is a good suggestion. I know there are aftermarket filter screens that you can slip over K&N filters, but I don't know how much additional protection that offers from dirt/dust. I run straight velocity stacks on my honda cb350 roadracer, but I am not worried about dirt on that bike since I only run it 8 miles at a time.

The filter on the breather hose is also a good idea. I have a bunch laying around that I think will fit.

 

[pmdave]

The flat BMW filter is pretty good, and the square airbox fits over the transmission nicely, providing a place to catch the breather blowby oil. The only change I would suggest to that system is if you have a cast aluminum filter top. The later (plastic) version is lighter, smoother, and provides good intake vacuum for those Bing carbs to function correctly.

Timing plugs will snap right into the holes in the aluminum filter base once you remove the air tubes.

pmdave

 

[Ray1505]

Re-Psycle sells a kit to get rid of recurculation gases system. Not very expensive and it works. Bike runs good too!
I even took the front solenoid out from under the engine top cover.

 

[Jeff488]

I used oilhead oil drain plugs/washers with a good dose of anti-seize compound to plug my heads.

 

[ducatipaso]

yup i did it

 

[lbrackr756]

[QUOTE=pedrocasper;281295]I have a 1984 R100, in which I'd like to remove the Pulse Air Injection System (PAIS) and traditional airbox. I found the following article on internet riders.

http://www.ibmwr.org/r-tech/airheads/plug_fresh_air.shtml

I'd like to put K&N round/bullet type airfilters on the bike for a more traditional cafe look. My concern is the breather hoses and fittings. I like to run the breather hose into a nice catch can I will mount on the bike. I have done this on smaller displacement honda CBs that I race, but was wondering if anyone has done this on an airhead. I will still be using this bike as my street bike, so I don't want to really screw things up for pure asthetics and limited power gain.[/QUOTE]

I just used a 5/16" ball bearing inserted where the tubes come out of the airbox. Took 5 minutes and the bike still looks bone stock.

 

[Stuff2c]

remove the tubes from the heads, remove the tubes from the nuts (takes a little work) braze them closed and reinsert.

 

[JOHNP]

Did it

After a measly 17k miles on my 84 R100 with the air injection system on, and the serious admonitions at the Vermont rally to get rid of it, I pulled my system when I returned (but saved it). Debated whether to plug the lines with ball bearings to preserve stock look or to yank them and decided to yank them for a cleaner look. Fortunately the head connections came out easily. Bob's BMW sells a kit with threaded hex plugs for the heads and rubber plugs for the airbox. Decided to keep my airbox stock. Biggest time was pulling up the stock airbox to paint it and also replaced the crossover fuel line (original and leaking) underneath the airbox while I was at it.

 

[lkchris]

Since K&N filters don't filter anything, be sure and post your VIN number so we can all avoid your bike when you decide to sell it.

 

[pedrocasper]

Since K&N filters don't filter anything, be sure and post your VIN number so we can all avoid your bike when you decide to sell it.

You know, suggested alternatives are always welcomed along with wise cracks.

 

[keelerb]

I have always considered K&N filters to be the best. What am I missing here? (Please resist the urge to respond, "Large chunks of dirt....") Thanks - BrianK

 

[bikerfish1100]

I have always considered K&N filters to be the best. What am I missing here? (Please resist the urge to respond, "Large chunks of dirt....") Thanks - BrianK

lots of noise from some car & truck testing of K&N air filters, along with other brands.
K&Ns don't filter especially well until after they have built up some layer of collected yuck.

 

[sumran]

I have heard from several experienced mechanics that the K & N filters allow a substantial amount of fine particles to get into the engine. I have also been told by many that I respect that the stock BMW filter is hard to improve on, especially the flat filter that came on later airheads. That is what I have on mine. When I change it there is dirt on top of the filter and none in the carbs or the airbox below the filter. I have also been told that cleaning and reusing the stock filter will cause premature wear.

The don't cost that much and they don't have to be changed that often, so I stick with the stock ones.

 

[widebmw]

You know, suggested alternatives are always welcomed along with wise cracks.

A good alternative is the UNI filter, oiled foam.
http://www.unifilter.com/online catalog/streetbmw.html

 

[20774]

I have always considered K&N filters to be the best. What am I missing here?

One person's opinion is here http://bmwmotorcycletech.info/K & N.htm and seems to be shared by many on the Airheads tech list.

 

[BRICKRIDER]

lkchris: Since K&N filters don't filter anything, be sure and post your VIN number so we can all avoid your bike when you decide to sell it

"The Sting of Criticism, is the Truth in it." -- Benjamin Franklin

 

[The_Veg]

...the stock BMW filter is hard to improve on, especially the flat filter that came on later airheads. That is what I have on mine... They don't cost that much and they don't have to be changed that often, so I stick with the stock ones.

The late-model airhead filter is of similar construction to the filter my car takes, but is half the size and three times the price.