Your Motorcycles: BMW

Jacks Nice 1976 R/90S:

Hi....... Thought I'd send ya a few snap shots of my 76 R/90S that's been in my ownership for the past seventeen years now. Some of the modifications include an over bore of .180 using R100 9.5 compression pistons and I've applied a thermal barrier coating to the piston crowns, BMW 336 sport cam, lightened the flywheel by almost 3 lbs to reduce rotating mass to reduce tranmission down shift clunking along with giving more positive and quicker upshifting but the most noticeable effect was the engines abilities to rev up quicker. The heads features include Kibblewhite Black Diamond stock size valves, intake ports have been epoxy filled to reduce port volume in order to pick up port velocity do to the oversize stock ports, combustion chambers along with the valves have also a thermal barrier coating applied in efforts to obtain lost energy and some very tricked out seat work. The carburetors are Mikuni 38mm FlatSlides mounted to a venturis spigot manifolds, love those flatslides!

The frame has also recieved special treatment to help it track straighter throught a curve thus giving me more confidence to push it harder than usual in efforts to keep pace with my friends. All in all this in one bad and fast old BMW that I truely enjoy riding and with 103,000 miles registered on the old odometer, she still turns a few heads.
Jack Hara


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