I know this is a "photo thread" but having my CT-90 for about 2 years and with the season for most of us just starting:
I've got a sweet starting & running CT-90 as of about a week ago...prior to that it was getting hard to start and would at times stall out. I did a couple of easy things that seem to have really made a diffrence and just wanted to pass them on. Ice cold starts in 3 kicks honest!
First - added small inline fuel filters to both fuel lines (main and reserve line) just prior to the petcock. There is room and all you do is cut and insert. This will keep crud out of the carb. About $3.00 ea.
Second: Cleaned the carb body and interior really well. I ordered and installed a jet kit from DR.ATV and replaced all the springs, jets, needle valve, float valve. About $24. Easy as your just taking out a part, and replacing it, one at a time. Many of the old parts were showing wear...so fiddle as I might, until you have good parts your just wasting time. The Dr. even sells whole carbs at a decent price.
Third: Got a new battery and a 6vt. maintainer and installed a pigtail plug under the side cover.
Anyway...I'm kicking myself for waiting so long to redo the carb with new parts.
Photo: cleaning out the garage...