Saw this on Mark's swap

[wfopete]

http://www.vintagemx.us/cgi-bin/largephoto.cgi?C=aMeRorHdMveRTqoH&w=5

Pete Petrick
175 Jackpiner
Slow but Good

[454MRW]

The cylinder fins are shaved or ground in a strange way, maybe for clearance for accessibility to the carb or removal of the braces, not like previous cylinder fin modifications that Jack had one of his bikes? Mike
http://pentonusa.org/forum/topic.asp?TOPIC_ID=15318&whichpage=1&SearchTerms=jacks%2Cbike%2Ccylinder

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

[tooclose racing]

Agree - that jumped out at me.  Interesting silencer arrangement on the stock pipe.

Nice looking bike.  But WHITE?  [8D]