Douglasmotorcycles.net

General => General Douglas Discussion => Topic started by: Evanc on 24 Dec 2013 at 12:11

Title: Valve clearances, Hot or cold?
Post by: Evanc on 24 Dec 2013 at 12:11
Hi guys out there in Douglas land. I have just purchased what I believe is a mark 3 that has a Mk5 frame, not sure why it was swapped. I am interested in setting the tappets but am unsure wether they are set hot or cold. It has 6 thou on a plate on the crankcase. Any advice is appreciated, thanks, Evan from Oz
PS hope you all have a merry Christmas, stay safe
Title: Re: Valve clearances, Hot or cold?
Post by: eddie on 24 Dec 2013 at 18:14
Evan,
          Most Mark series engines had 'Tappet clearance .005' stamped on the top of the crankcase. If yours has a plate with 6 thou clearance stamped on it, then perhaps the engine has been rebuilt with special cams - in which case, it's anyone's guess as to whether that is measured hot or cold. Also, Mark series engines have steel pushrods, so the clearance hardly changes with temperature - unlike the Plus series and Dragonfly with their alloy pushrods.

   Regards,
                 Eddie.