There’s an inch in it
AFTER ANOTHER SHOVELHEAD ‘outage’ due to a smoking rear pot, fixed with new valve stem seals, it’s now time to change the perfectly good Keihin carb for a Dellorto PHM40. Super Mick Read (Radical Precision, Peterborough) machined a nice adaptor flange up in ally and the big Dellorto pumper now fits like a huge loudhailer on top of the 45º Vee. Now the bother begins. The stroke of the stock H-D twistgrip is only 31mm, the big Dell needs 41mm. The choice is to either mess with the original twistgrip to allow more throttle barrel movement, or fit a different single pull body. H-D in their wisdom like a 1-inch handlebar diameter. Normal factories have largely agreed on 7/8ths of an inch diameter. So fitting a new twistgrip means changing the ’bars and spacing out all the one-inch diameter clobber (switches, clutch perch, front brake) with 1/16-inch semi-circular shims. It will all be worth it when the job is done. In what way I don’t know. It’s still an old Shovelhead. But I do like a 40mm Dellorto and a gauze bellmouth.
Mark Graham Contributor Smoking rear pot rectified it’s time to address a part of the Shovel that’s actually working properly. A new carb it is then…