General Category => General Discussion => Topic started by: coxy on July 09, 2017, 09:23:06 PM

Title: Disc valve 180 degrees out?
Post by: coxy on July 09, 2017, 09:23:06 PM
Gday all
There's been a few posts about putting the valves in 180 degrees out could someone tell me how this is possible as far as I can tell it can only go in one way as there keyed and marked unless the collar can go in upside down ?
Cheers
Title: Re: Disc valve 180 degrees out?
Post by: BRT-GTR on July 10, 2017, 07:51:34 AM
   Hi Coxy,
                  You are correct in what you say for the right, drive side end of the crank.

      The collar can only be fitted in one position over the pin on the crank. However, the disc valve can be fitted to the collar in two positions, 180degs apart,  due to the spline arrangement. If the manual instructions are followed, incorrect fitting of R/H disc is unlikely to happen, just line up all the dots and the pin.  This is why it is important to fit the right disc first.

          When it comes to the left end of the crank which is drilled right through, it is easily possible to fit the collar or disc 180degs out of position and it has happened. The crank end does not have a dot to guide you, so fit the right disc first and then make sure the left disc is installed at 180degs to it. (Then put a dot on the crank end for future reference). 
         If just the left side is stripped, the disc can be correctly installed by putting the left piston at TDC and installing the collar / disc so that the intake port is open.

     Here's a link to a recent post on a similar theme (will post when I find it) showing pictures of the of the crank ends with discs fitted.                                                     Brian.
Title: Re: Disc valve 180 degrees out?
Post by: coxy on July 14, 2017, 03:17:05 PM
thanks Brian very interesting cheers
Title: Re: Disc valve 180 degrees out?
Post by: BRT-GTR on July 18, 2017, 05:48:42 AM
             Found the link to the post I mentioned, see photos at end.

                 http://bridgestonemotorcycleparts.com/index.php?topic=4070.msg23092#msg23092 (http://bridgestonemotorcycleparts.com/index.php?topic=4070.msg23092#msg23092)