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Title: Port Timing Specs
Post by: john durrill on October 16, 2001, 01:29:16 PM

Does anyone have the stock Port Timing Specs for a 125 Sachs or the 175 Jackpiner engine? I would like to degree out both . if you have just measurements in mm or Inches that would do i can convert them. The Specs might be with tips on getting more power. Some times they are reffered to .
I had one cylinder that was degree'ed and it was with out a doubt the best running one i owned.
Larry , Kip , Doug ......anyone....... chuckle, chuckle
Thanks,
John D.

Title: Port Timing Specs
Post by: Steve Minor on October 16, 2001, 01:42:47 PM

I have the 1977 manual from my 400 GS6 that has the 175 Piner stuff in it too. It says the 175 Piner timing is "3.00mm btdc"

hope that helps

Title: Port Timing Specs
Post by: grandpaul on October 16, 2001, 02:06:05 PM

Ignition timing and port timing are entirely different, only related in reference to the position of the flywheel (crank). The port timing can be altered by cutting away material at either the top or bottom of the intake and/or exhaust ports at the inside cylinder wall. Best left to experts, even a small mistake will render your cylinder as scrap.

GrandPaul,
Host of the Vintage Bikes forum at //www.delphi.com/oldbikes and the Triumph Bonnevilles Forum at //www.delphi.com/grandpaul

Title: Port Timing Specs
Post by: john durrill on October 16, 2001, 02:56:41 PM

Grandpaul,
It is something that does take understanding
But it can be done with just some hand files and sand paper , if you have the patientce to do it.I did a lot of port work years ago.
Almost always its a compromise with the factory tolerences and the specs the engine people designed it to. But it is worth the effort.
John D.

Title: Port Timing Specs
Post by: Steve Minor on October 16, 2001, 03:46:10 PM

oops.......guess I showed my ignorance... I'll learn with time......

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General Discussion => Penton Talk => Topic started by: john durrill on October 16, 2001, 01:29:16 PM