The mechanic rebuilt the carbs, and I know it's possible it wasn't done right, but do you think I should skip worrying about the engine for now, and just concentrate on the carbs?
BTW you do have to fiddle with the idle screw a bit when starting cold. And another problem i read is your commute is only 8 miles one way, I see other issues like lack of charging the battery fully, moisture in the exhaust, etc. On your way home I would take it out for a good spirited 15 mile ride just to get the condensation up and blow the carbon out. These bikes like to be ridden not commuted on.
I'm going to learn more about working on my carbs at home and go from there. I'll browse a few threads before asking for help. Thanks for the suggestion on going for a 15 mile ride for condensation. I didn't see this post until today, so I will try this starting Monday after work.
Thank you to everyone for their help. I'm running now with not touching the idle stop screw at all. I start her up, throttle 1/4 turn, slowly open the choke, and keep the throttle at 2000RPM for about minute and half, then take off. At stops lights if I see/feel her dropping past 1000RPM I'll throttle it back up to 2000RPM then take off on green. By the time I get to work, it stays steady at 1200RPM. But my ride is pretty quick. Around 15 minutes.
Needing constant idle screw adjustments suggests the carbs need attention. Only occasional tweaks should be needed.
Thanks for the instructions. The mechanic rebuilt the carbs, and I know it's possible it wasn't done right, but do you think I should skip worrying about the engine for now, and just concentrate on the carbs?
Leave a little early and get the bike up to full temp. You want to burn off all the condensate that builds up over night your pipes and other parts will last a lot longer if you get them to full operating temp. Some of that water will end up in your oil you don't want that. So get her hot.
Thanks for the info. I'll do this as well. I felt that I shouldn't have to touch the idle stop screw, so I'll look into a different mechanic. He works on CB's often and was recommended but it's worth it for me to look around, like you mentioned.
Ah, the smoking gun....
When the carbs on these 40-year-old bikes are removed, if the tech did not FIRST soften the hoses that hold the carbs to the head, they became permanently stretched and will not seal well, if at all. It takes some work to make them seal again. Also, the O-rings in the castings that bolt these hoses to the head are now hard and should be replaced: Honda sells them, and I replace a lot of them. When they leak, it makes the carbs mix richer than normal, because these mixers run 12:1 ratio at idle, so if the vacuum is lower than it should be, that carb is richer than it should be. This is common to all these bikes (among others.).
I'd strongly suggest replacing the O-rings in those castings before making yourself crazier, and also closely check the hose clamps (all 8 of them) that connect the carbs to the hoses: they may need to be tightened more, or the hoses replaced. Honda still sells them, I just bought a set for my own 350F.
Thanks HondaMan,
Working on my carbs is my next step of education on my bike.
Side note: I adjusted the clutch cable the other day too, and she's been riding great.
