Grant demystifies the black art of Tire Changing and Repair to help you STAY on the road! "Very informative and practical." See the trailer 
Cotton or synth sweat-wicking t-shirts with the Horizons Unlimited logo on the front and a snappy slogan (changing every year) on the back.
Show your route on your panniers. Great conversation starter when you meet people on the road!
Motorcycle and travel books to inspire and inform you!
ll 5 DVDs with a custom printed slip case. "The series is 'free' because the tips and advice will save much more than you spend on buying the DVD's."
|
|||||||
| BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only. Questions comparing which bike is best etc go in the "Which Bike" forum. |
 |
|
|
LinkBack | Thread Tools | Display Modes |
|
#1
9 Jul 2009
|
|||
|
|||
|
R80 - hissing warm piston
I was out for a long run on my bike the other day and noticed that the right piston seemed to hiss when I got back to the garage and had switched off for 5mins+ or so. Is this likely to be a blown gasket? I looked for water on the piston (rain?) but couldn't see any, nor could I locate the exact source of the hissing (an identifiable gasket area). I am clearly a novice airhead. Any ideas anyone?
__________________
__________________________________________________ _________________________________ Please support my motorbiking travel fund by playing http://fantasy.cycling-games.com 
|
|
#2
9 Jul 2009
|
|||
|
|||
|
Noticed a similare (same?) sound from my left Sibenrock overhauled head... it seems to be the re-welded exhaust threads that is the culprit in my case... Siebenrock had failed -utterly- to weld the aluminum and re-thread it propperly (I simply did not have time to deal with it so I installed the "faulty" head anyway).
The headgasket is said to produce a twittering sound. A hissing sound is more likely to be a leakage from the exhaust system (back-pressure). Check the connection between the down-tubes and the muffler/silencer also - they do tend to leak there and that does also create a hissing sound. When the valveguides are -worn- you may also get a hissing sound; when you look at the inside of the covers (which should thus not be pained on the inside...) it should be just a clean oily surface; if light brown it could be ok, but if darker brown or black - that sides valve guide is leaking. What should not cause a hissing sound is a loose stub. Detach the carbs and check that the stubs are seated firmly in the heads - just incase... The stubs have a tendency to got loose, and thus causing air-leakage (too lean mixture) which cause too hot engine running, causing augmented wear of the guides and risk to loose valves (valvestem braking/separation).
__________________
Drive Safely, Albert
|
|
#3
9 Jul 2009
|
||||
|
||||
|
This can be a normal thing. There is a small gap in the gasket on your valve cover that allows water between the head and the valve cover, but not into either of the sealed sections of the valve cover, so your oil isn't getting contaminated. There is a small pocket that can fill with water and it will continue to hiss well after the engine is shut off. Look in the center of the valve cover on the top edge.
|
|
#4
10 Jul 2009
|
|||
|
|||
|
...forgot that the covers lack a hole that drains the room inbetween the "rocker-cups"...
It can hiss quite strongly when residual water is "steamed off"... Notice the hole above the center bolt - "drainage". On the lower side I've just made an opening/gap between the covergasket and the cover.
__________________
Drive Safely, Albert Last edited by dc lindberg; 12 Jul 2009 at 08:38.
|
|
#5
12 Jul 2009
|
|||
|
|||
|
Thanks guys. It seems to be the 'hole that drains the room in-between the "rocker-cups" '. A major relief as there are many pressing service issues to deal with before opening that can of worms.
__________________
__________________________________________________ _________________________________ Please support my motorbiking travel fund by playing http://fantasy.cycling-games.com
|
|
«
Previous Thread
|
Next Thread
»
| Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests) | |
| Thread Tools | |
| Display Modes | |
Linear Mode
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Trouble starting when warm | stari vujadin | Yamaha Tech | 1 | 2 Jul 2009 10:58 |
| Warm night.... | Joybringer | Welcome to HU | 2 | 2 Nov 2007 12:53 |
| Warm Temperature helmets - HJC bi moto ??? | goodwoodweirdo | Camping Equipment and all Clothing | 1 | 3 Oct 2007 17:39 |
| Will my sleeping bag be warm enough?! | Chris of Motocross Africa | Equipment Reviews | 17 | 5 Jan 2007 12:18 |
| How long to warm up engine oil | goodwoodweirdo | Yamaha Tech | 6 | 28 Oct 2005 19:23 |
All times are GMT +1. The time now is 10:20.
