|
18 Dec 2010
|
|
Gold Member
Veteran HUBBer
|
|
Join Date: Oct 2005
Location: Brittany, France
Posts: 401
|
|
Glowing exhaust pipes on an airhead
I have a '78 R100 RS Motosport. I've had it for several years but for the last 4 it's been mothballed in France.
I'm intending to start using it again this year but it has always had a fault I've never got to the bottom of.
It seems to run fine but if left ticking over while stationary for more than a few minutes the exhaust pipes start to glow. Just a dull red at first but then soon turn to cherry red.
I've checked the timing (several times). The plugs show no sign of running too hot. It pulls cleanly all through the rev range and as soon as I start moving they cool down.
But something's not right.
The only non-standard thing about it is that the pipes are stainless. Could it be they are thinner than normal? Does unleaded run hotter than the 4* the engine was designed for?
Any ideas please?
__________________
If you think you are too small to make a difference you have never spent the night with a mosquito.
|
18 Dec 2010
|
Registered Users
HUBB regular
|
|
Join Date: Dec 2010
Location: Los Angeles
Posts: 27
|
|
stainless pipes are usually thinner walled or single walled..... they may get hotter, I dunno I never had any stainless pipes on my Beemer, but as u have had it in storage there may be a chance that there is an air-leak between the carb and the carb boot.... this could make it run lean thereby making it run hotter, though you say it does not appear to be hot. also it is Air cooled, they really don't do well just idling away and not being run, in the workshops we always used to use a fan in front of airheads to keep em cool if we had to run them up for more than a minute or so........ just a thought..
M
__________________
|
18 Dec 2010
|
|
Registered Users
HUBB regular
|
|
Join Date: Sep 2009
Location: Melbourne
Posts: 65
|
|
Stainless not a good conductor
As the title says S/S does not transmit heat quickly, a fan is good advise. After all, it is an Airhead.
Cheers from Oz.
__________________
I'm not getting older; I'm just progressing through LIFE!! Harleys do not have a throttle- they have VOLUME control!!!
|
18 Dec 2010
|
|
Contributing Member
Veteran HUBBer
|
|
Join Date: Mar 2005
Location: Northumberland, uk
Posts: 761
|
|
Hi Harleyrider I have stainless pipes on the Bilgepump and they never get that hot, something seems wrong. As you seem to have eliminated everything on the ignition system and your sure the carb's are fine it must be the exhaust valves sticking a bit, stretched or cracked or the seats worn allowing gases to burn into the exhaust ?. The valves are prone to stretching and parting company with the heads at mileage as low as 60 thousand plus miles. Jake.
Last edited by adventure950; 18 Dec 2010 at 13:59.
|
18 Dec 2010
|
Registered Users
Veteran HUBBer
|
|
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
|
|
Quote:
Originally Posted by harleyrider
I have a '78 R100 RS Motosport. I've had it for several years but for the last 4 it's been mothballed in France.
I'm intending to start using it again this year but it has always had a fault I've never got to the bottom of.
It seems to run fine but if left ticking over while stationary for more than a few minutes the exhaust pipes start to glow. Just a dull red at first but then soon turn to cherry red.
I've checked the timing (several times). The plugs show no sign of running too hot. It pulls cleanly all through the rev range and as soon as I start moving they cool down.
But something's not right.
The only non-standard thing about it is that the pipes are stainless. Could it be they are thinner than normal? Does unleaded run hotter than the 4* the engine was designed for?
Any ideas please?
|
Oh but it is
That is exactly what happens
Nothing to worry about. As soon as you start driving so that you get some wind on the down-pipes they should stop glowing. If that is what happens - all is well
s/s pipes glows less than the original steel pipes.
RS 1000cc from late 70:ties glowed the most. You do have the 40mm down-pipes, right?
Later 1000cc RS models with 38mm down-pipes does not glow as instensly, they only turn sort of orange-/red:ish. 800cc and less cc should never glow.
__________________
Drive Safely,
Albert
|
18 Dec 2010
|
|
Contributing Member
Veteran HUBBer
|
|
Join Date: Mar 2005
Location: Northumberland, uk
Posts: 761
|
|
That's interesting Albert I had an 100rs back in the 70s the pipes I recall were really blackened and it had heat shields down over the front downpipes - must have been the reason why but I never recall them getting orange or cherry red mind you I was younger and just rode the thing never really took much notice of stuff - I suppose you don't when your in your teens. Is it just the rs and s models or do most of the 1000 get the same. ?
|
18 Dec 2010
|
|
Gold Member
Veteran HUBBer
|
|
Join Date: Oct 2005
Location: Brittany, France
Posts: 401
|
|
This is my 2nd RS. My first 1 was also a '77 model which I owned in the early 80s. I used it for despatch riding and did over 200,000 miles on it in 2 years. I'm sure that didn't have glowing exhausts. Hence my thoughts the cause could be either the stainless pipes or unleaded petrol. I'm not sure what size pipes they are and I'm not with the bike at the moment to measure it.
I realise it's not good practise to leave a bike ticking over in the workshop for long but I don't expect the pipes to start glowing while I'm sitting at traffic lights. This isn't a new problem after it's been stood for a while. This is something that was happening all the time in the 2 years I rode the bike before it went into storage.
Thanks for all your replies. I'm tempted to find some standard pipes for it and see if that cures it, but I'm also wondering if I should be making some adjustment to the timing for unleaded fuel.
__________________
If you think you are too small to make a difference you have never spent the night with a mosquito.
|
19 Dec 2010
|
Registered Users
Veteran HUBBer
|
|
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
|
|
...not a controversy again...
Guys.
RS 40mm down-pips are known to glow when driving in traffic jam, especially on warm -dry- summernights.
There is no way you can expect to see this in day-light.
As with all things in the world - it is not an absolut truth. There were those who did not have glowing down-pipes when subjected to longer periods of idling, and that was considered "weird" back then.
Yes - 1000cc are prone to get the down-pipes glowing. RS 70hp from the 70:ties did simply glow the most.
Undressed beemers do not have glowing down-pipes in corresponding frequency. It -might- thus have something to do with cooling of the whole engine.
As for not seeing that they glow... hardly where once attension should be focused in traffic-jam, at redlights, etc...
If you still are worried - install two pip-fans so that you can get some "wind" on the barrels at idle; my mechanic have done so on his side-rig after he noticed his red down-pipes (after driving some 40 years and >>>1 000 000 miles...).
He has a 90A Bosch alternator installed so there is plenty of electricity to drive his fans - on a stock 280W there is -no- extra ampères at idle for any extra equippment incl drivinglights...
What I have on my primary beemer, that I do think interfer with the glowing, are:
- deeper oilpan / spacer
- oil-cooler
- belt and pulley driven car alternator
- dual ignition
- s/s exhaust system
The last beemer I aquired, R100RT 1981, does have glowing down-pipes when driving down-town in traffic jam with way too much idling. Hence my guess is that dual-ignition and improved oil-cooling does play a significant role in lowering the temperature of the exhaust fume so much that it is hard to get the down-pipes glowing; and the strong fan on the Bosch 70A alternator (older external version) do also matter I guess.
Just except the fact that most 1000cc down-pipes are prone to glow. RS pre nicasil barrels (pre -81) are more so than other 1000cc's. One -can- get both 800cc and 750cc down-pipes to glow as well, when one tries hard enough (not adviceable!).
__________________
Drive Safely,
Albert
Last edited by dc lindberg; 19 Dec 2010 at 16:24.
|
19 Dec 2010
|
|
Gold Member
Veteran HUBBer
|
|
Join Date: Oct 2005
Location: Brittany, France
Posts: 401
|
|
Thank you Albert. You've put my mind at rest. I'm not going to worry about it anymore.
__________________
If you think you are too small to make a difference you have never spent the night with a mosquito.
|
Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
| |
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.
"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™ 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!
Every book a diary
Every chapter a day
Every day a journey
Refreshingly honest and compelling tales: the hights and lows of a life on the road. Solo, unsupported, budget journeys of discovery.
Authentic, engaging and evocative travel memoirs, overland, around the world and through life.
All 8 books available from the author or as eBooks and audio books
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.
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.
|
|