Savager wrote on 08/01/10 at 23:37:26:Bill, it's bad, unfiltered or aged gas that I think is the primary problem.
Well the bike performs @ 95% now
, I think the pilot jet may be too lean in these from the factory. I've got a 40 w/ bleed holes I never used from my sold GS500 that I may bore slightly larger than the 52.5 if I can borrow the boring tool from a canic I know, as well as get the old pilot out w/o taking the carb off again.
Anyone ever remove the bowl and bottom jets w/ the carb on the bike? It is doable.
Most of the crud found in the old carbs is from old fuel that was left in the carbs as they sat unused for years; and of course those left outside in the elements were the worst. It goes from gummy to hard varnish, but there is usually plenty of grit to go with it so it is getting in there dispite the stock filtering system
Take a close look at the filter mount...just 1 screw on the outside of the box holds the filter in place, leaving the rest of it to flop/vibrate around when running....very easy for unfiltered air to get in.
Some of the bikes which are left inside garages or sheds at least were started on occasion; at least more so than those left outside.
Not sure why that is so unless those who keep them in covered storage just take better care of equipment in general.
But that is what I have found over the years when operating on the carbs
The plastic/rubber piece on the choke assembly which screws in to secure it, that is probably most damaged part of an old carb, even more than the pilot air adjusting screw. I have to order replacements frequently for a rebuild.