QuestionI have a 1983 Honda vt500c shadow that needs it's tach drive gear replaced. I want to know how involved it would be to replace with the engine in the frame before i start opening things up. I have the Clymer book but it doesn't cover this.
AnswerBrian, the tach drive is part of the camshaft holder. see illustrations
http://www.cmsnl.com/honda-vt500c-shadow-500-1984-usa_model7640/partslist/E++02....
Try an online download of the shop manual for details.
http://www.hondahookup.com/manuals/ Manual may just show the process with motor removed, though.
http://autos.groups.yahoo.com/group/ascotvt500enthusiasts/ join and search for details.
I had an Ascot last year, but can't recall if the motor needs to drop down/come out or can be left in place with some of the upper hardware removed.
Sometimes the biggest challenges are stripped threads in the head, when removing/replacing the bolts. Also, if you are able to get the valve cover off, to access the valve train, back off the valve adjusters and/or turn the motor over so that the valves are on compression stroke (valves closed) to relieve the valve spring pressure on the camshaft/holder for removal.
Bill Silver