rec.motorcycles.racing References: 1 I've bored plenty of carbies. You have to offset the new bore to the top, or your idle transition and tickover go to hell. The limit then is the thickness of the carb casting at the upper side of throttle bore. Some carbs are made in the same castings as the next size bigger; uually no problem going up considerably. If the carb is on its own pattern, you may be limited to about 1-1.25 mm increase. -- -- Regards, Hoyt McKagen To prevent virus propogation, please don't put this addy in your book Belfab CNC - http://www.freeyellow.com/members/belfab/belfab.html Best MC - http://www.freeyellow.com/members/batwings/best.html Camping/Caving - http://www.freeyellow.com/members/batwings/caving.html Two-Wheel-Tech List - http://batwings.freeyellow.com/2whfaq.html It's called 'Mad Cow Disease' because 'PMS' was already taken.