I started troubleshooting the idle issue the bike has been having. Basically, you have to keep the idle above 3000rpm otherwise it’ll stall out (for reference, correct idle setting is 1100rpm). Pretty obvious given that the bike sat for about a decade, that the problem is somewhere in the fuel system. Figured I’d start with the carb, so I took off the fairings, tank, and airbox to get access. You do have to dig pretty deep into the bike to get at the carb, but everything is well placed and nothing was particularly difficult.
I got the carb out and gave it a good soak in cleaning solution, blew out all the passages and ran some guitar string though the jet. I’m actually not impressed by this Dellorto SHA at all. First off it’s only a 14mm throat so I’m fairly certain it’s a choke point. Shit, I upgraded to a 20mm slide carb on my 50cc Ruckus (stock is a 15mm CV carb) and the low speed fueling can still be dialed in.
But size aside, my biggest complaint is that there is ZERO adjust-ability. The only serviceable jet is the main jet, the only control is the idle adjust screw. That bell has no smoothing features to aid airflow. With those complaints in mind, I ordered a new Malossi PHBG 21mm slide carb as an upgrade. It should give me the adjust-ability I generally like to have and will have extra headroom if I decide to put a bore kit on the bike.
Since I couldn’t do anything else on the carb until the new unit comes in, I decided to go in and do a full fluid service. Changed the coolant and the gearbox oil.
Other things I found. There is a broken wire coming off the coil. The colors do not exist on the wiring diagram, so I’m not really sure what to do with it yet.