These are the photos from the seminar Lance and I did at the 2008 Pennsylvania Airhead Supertech Weekend, February 1-3, in Boyertown, PA. Click on the first thumbnail below to view the large picture and see the detailed caption. Beneath the caption, you can re-size the picture for a larger or small view. On each page, click "next" to advance. You can return to the thumbnails at any time.

• References:
o Scot Marburger, http://www.airheads.org/content/view/304/98/ or http://www.gunsmoke.com/motorcycling/r100gs/pushrod_tubes/index.html
o BMWMOA Tech Forum, http://www.bmwmoa.org/forum/archive/index.php/t-2080.html
o Snowbum, http://bmwmotorcycletech.info/pushrodseals.htm
o Clymer, BMW R-Series, 1970-1994, Ch. 4.
o Oak Okleshen, Boxer Top End Disassembly & Reassembly, 1970-1995
o Anton Largiader, “Airhead Rocker Arms and Posts”, http://largiader.com/tech/rockers/

• Tools needed:
Finned exhaust nut wrench
Assorted spanners & sockets
Circlip pliers or small L-hook, depending on model year
H-shaped jig for adjusting ’70-’75 rocker arm assemblies
Rubber mallet

• Parts needed:
Pushrod tube seals (2)
Wristpin circlip(s)
Cylinder base O-rings ’78-on
Cylinder stud O-rings ’76-on
Optional: spare finned exhaust nut
Optional: spare valve-cover gasket

Re optional parts: if you live 10 minutes from a dealer, you can pop over in the car if you screw up your exhaust nut or lose the circlip. If you live 100 miles from the dealer or get all your parts by mail, you might want to stock these spares so you don’t sideline your bike for a week when a 2 hour job runs into a roadblock.

• Materials:
Anti-seize (finned exhaust nut threads, spark plug threads)
Cylinder base sealant
PRT seal lubricant
Clean engine oil or assembly oil

• Lubing PRT seals:
o Silicone grease on inside, engine oil on outside – Scot Marburger, http://www.airheads.org/content/view/304/98/
o Silicone grease on inside, engine oil on outside – Snowbum, http://bmwmotorcycletech.info/pushrodseals.htm
o GE Clear Silicone Auto Sealant, inside and out – Tom Cutter, email 12/18/07
o Gascacinch (VW dealers), inside and out – Matt Parkhouse, email 12/23/07
o Engine oil, inside and out, NO sealant – Oak’s Top End Manual

• Sealing cylinder base:
See http://www.gunsmoke.com/motorcycling/r100gs/sealant/index.html
Cutter: Three Bond No. 1209, aka Yamabond
Clymer: Three Bond No. 1216
Oak: Hylomar or Permatex Hi-Temp RTV No. 27B
Parkhouse: VW Gascacinch
Snowbum: Dri-bond (BMW dealers may have it); Permatex Hi Temperature RTV, type 27B (81422); and Pro-Seal red silicon RTV (80726), Hylomar
O-ring (’78-and-later):Lube with engine oil no more than 15 minutes prior to reinstallation.

Acknowledgments: THANKS to the following:

Maryland Airmarshal Lance McKay, for the use of his R50/5 for most of these photos, his hospitality and the use of his tools and garage, and finally for agreeing to help me with this hare-brained project.

Pennsylvania Airmarshal Todd Byrum, for the use of his workshop, and his support and advice in developing this presentation. PA Airheads ROCK, thanks to Todd.

Pennsylvania Tech-marshal Bob Sipp, for keeping us on our toes and answering a zillion stupid questions.

Al Vangura, for the use of his exquisite cutaway '82 R80/7 demonstration motor, featured in several of these photos. Al is an incomparable machinist, and his beautiful cutaway components have lead many Airheads down the path of mechanical enlightenment.

Oak Okleshen, Tom Cutter, and Matt Parkhouse, for their assistance and advice supplied in the preparation of this presentation.

Disclaimer: Any errors or omissions in the following directions are my own, and not attributable to any of the above contributors. That said, if you attempt this procedure, you’re assuming responsibility for the welfare of your engine and the safe operation of your motorcycle. If you aren’t confident about proceeding, consult a more experienced mechanic or your BMW dealer.

Your comments and questions are invited. You can add them below, following the thumbnail pics, or email me at 4mohans@safe-mail.net. If you expect a response, email me.