Testing valve springs

Valve springs can lose a lot of their strength over the years, as seen with this R25/3 valve spring: a new spring measures 16.6 kg, the old spring 10.1 kg, almost 40% lower. Lower spring tension usually causes no or minor problems on low revving engines, but it can lead to loss of power / misfiring on higher revving engines as a result of valve float                 The test device:  

Statistics

Some statistics based on last 5 years (2013 – 2018)      

Rim width

The width of rims can be measured in 2 different ways: the inside or the outside. This means that one and the same rim can be indicated both in (for example) 2.15 “and 3.08″ WM2: inside 1.85″ (47 mm) outside 2.72″ (69 mm) WM3: inside 2.15″ (55 mm) outside 3.08” (78.2 mm)      

Leaking carburetors

A frequently asked question is how to fix a leakage of the idle mixing screw. Further tightening the nut of the idle mix screw is certainly not the solution: holes have been drilled in the idle mix screw which connects the idle mix chamber to the the outside air. If fuel leaks out through the same bore, it simply means that the fuel level in the float bowl is too high. (assuming that the bike is on the center stand, if the motorcycle is placed on the side stand, there is a greater risk of leakage) If the carbs keep leaking, it’s
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Websites

Fair calender Oldtimer & Youngtimer: https://www.messen.de/de/1278/branche/oldtimer-und-youngtimer (mainly Germany) BMW forum: http://2-ventiler.de/  (Deutsch) http://www.flat-twin-bmw.com/  (French)   BMW clubs Germany: http://bmw-einzylinder.de/   BMW clubs United States: http://vintagebmw.org/v7/ http://www.bmwmoa.org/ http://5united.org/   BMW clubs United Kingdom: http://www.thebmwclubs.org.uk/ http://www.theairhead.co.uk/   BMW clubs The Netherlands: http://www.bmwclubnederland.nl/ http://www.bmwcluboirschot.nl/ https://bmwmcnnl.nl/ https://www.bmwboxerclub.nl/v2/   BMW clubs Denmark: http://www.bmw-veteran.dk/   BMW clubs Indonesia: http://bmwclubjakarta.blogspot.nl/   Facebook: https://www.facebook.com/Bmwclassicmotorcycles/ (that’s us) https://www.facebook.com/groups/bmwold/   (Vintage & Classic BMW Motorcycles USA) https://www.facebook.com/groups/AirheadsAustralia/ https://www.facebook.com/profile.php?id=100001965546450  (Richard Sheckler) https://www.facebook.com/scottiesworkshop/ (Scottie Sharpe)   Information sites: http://w6rec.com/general-bmw-motorcycle-information/ http://bmwdean.com/ http://vintagebmw.org/v7/ http://www.beemergarage.com/ http://www.bmbikes.co.uk/information.htm https://bmwr12.net/ http://www.wildstar-fan.de/BMW/home.html (R25/2 restoration- Deutsch) http://labeheme.jimdo.com/ (/5 info – French) http://www.ibmwr.org/otech/chassis.html  (Survey of Chassis Numbers) http://weissundblau.blogspot.nl/2011_05_01_archive.html (after-market hubs) http://www.earlesfork.com/ http://www.trixondrums.de/glaeser/glaeser.htm (Gläser fairing – Deutsch) https://www.shannons.com.au/club/bike-news/old-bike-australasia-1937-bmw-r5-ss/ 
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