Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > BMW Tech
BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only.
Photo by Daniel Rintz, Himba children, Namibia

The only impossible journey
is the one
you never begin

Photo by Daniel Rintz,
Himba children, Namibia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 21 Jan 2008
Registered Users
HUBB regular
 
Join Date: Oct 2006
Location: Czech Republic
Posts: 21
Airhead valves

Hello all,
I'm going to change push rod tubes seals on my R100GS and at the same time want to inspect cylinder heads. The bike has 115000kms on the clock (it might be more, I own it since 70000), engine takes little oil, I'd say less than 0.1l per 1000kms and it isn't noisier than other airheads I've heard. The thing I'd like to know is if I should have valves and guides replaced and seats recut on the bike with such a mileage even if they are in their wear limits. I'm preparing the bike for a long trip and want to have everything 100%.

Please advise
Reply With Quote
  #2  
Old 21 Jan 2008
AliBaba's Avatar
Registered Users
Veteran HUBBer
 
Join Date: Apr 2001
Location: Norway
Posts: 1,379
0.1 l oil per 1000 km is pretty good for an engine of that mileage.

If you prepare the bike for a long run tour I would have overhauled the cylinder heads. I did it at 150kkm and it was needed.

It might be smart to check the pistons and rings to. My rings and piston (R80GS) were good at 150 kkm but at 180 kkm they where far outside the tolerance – but the engine was running nice.

Timing chain and clutch should normally last a lot longer the 115kkm but it might be smart to change them if they are original.
Reply With Quote
  #3  
Old 21 Jan 2008
Vaufi's Avatar
Contributing Member
Veteran HUBBer
 
Join Date: Jan 2004
Location: Munich, the beer capital
Posts: 1,046
Cool

While the engine is open, check the main bearings in the crankshaft as well. When I had to exchange the seals for the push-rods I checked my bank account and had the pistons & con-rods balanced on my R80GS. Jeez, what a difference! The engine runs so nice & smooth now.

Hans
__________________
Only when we pause to wonder
do we go beyond the limits of our little lives.
(Rod McKuen)
Reply With Quote
  #4  
Old 21 Jan 2008
Registered Users
Veteran HUBBer
 
Join Date: Feb 2006
Posts: 1,598
I would not take apart a good running engine to do this, but seeing that you have the valves out, i would fit new exhaust valves keeping everthing else that was in specification. If you change the guides, you will have to recut the seats. I would avoid removing metal for as long as possible.
Reply With Quote
  #5  
Old 22 Jan 2008
Registered Users
HUBB regular
 
Join Date: Oct 2006
Location: Czech Republic
Posts: 21
Thank you guys for your input.
I agree with oldbmw. I don't like to remove any metal unless it is necessary. I'll take a look at seats and I'll inspect guides using method described in repair manual. If they both look OK I'll probably replace only valves as a precaution against split exhaust valve head. I've heard or read warnings this may happen on the engines with high mileage. Is there any reason why I shouldn't fit new valves into old guides if they are in good shape?
BTW does anyone know new valve stem diameter? I know they are stated to be 8MM but I'm guessing they are slightly smaller. 7.98?
Reply With Quote
  #6  
Old 25 Sep 2008
Registered Users
Veteran HUBBer
 
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
How did it go ?
What did you chose to do ?

Ever heard of metal fatigue ?... get new valves!
__________________
Drive Safely,
Albert
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Buying an airhead BMW in South Africa Roboyobo BMW Tech 2 12 Dec 2007 21:32
gs 1150 burnt valves oddbod BMW Tech 1 13 Aug 2004 13:53
Which Battery for my Airhead? Story Leavesley BMW Tech 7 23 Dec 2003 18:33
adjusting valves and carburator Mark van der Molen Yamaha Tech 0 25 Apr 2002 02:44

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now
, and add your information if we didn't find you.

Next HU Eventscalendar

HU Event and other updates on the HUBB Forum "Traveller's Advisories" thread.
ALL Dates subject to change.

2024:

Add yourself to the Updates List for each event!

Questions about an event? Ask here

HUBBUK: info

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord travel protection is now available for ALL nationalities, and travel is covered on motorcycles of all sizes!


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Diaries of a compulsive traveller
by Graham Field
Book, eBook, Audiobook

"A compelling, honest, inspiring and entertaining writing style with a built-in feel-good factor" Get them NOW from the authors' website and Amazon.com, Amazon.ca, Amazon.co.uk.



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.




All times are GMT +1. The time now is 15:51.