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Discussion Starter #1
Hi all!

Following up on my original post (https://www.hondatwins.net/forums/4...388-1975-cb200-idles-6-000-a.html#post1062168) - before my intervention, I had a bike with wildly misconfigured carbs - just some screenshots from the post I made should help make that clear. As a result, the bike exhibited all sorts of bizarre behaviors. I think I'm on the other side of the hill at this point, but I'm still running into a few minor things that I wanted to follow up on in a single post to see if anyone had ideas about (a) if these are all indicative of a singular root cause and/or (b) what next steps a reasonable person may take:

I put ≈20 miles on the bike this weekend riding around the neighborhood and giving it some time to heat up over some short trips. Some things I noticed on those rides:

1. It backfires. Very. Loudly. I'll get a backfire when idling to a light, typically. It's relatively rare - once in every 20 or so idle-to-stops.
2. If you get into the 6k RPM range in 3rd or 4th, and you're cruising along at ≈40mph, suddenly the throttle will just take off! I'll get an instantaneous boost from the throttle as if I suddenly had jerked it up, when in fact I have a steady hand on it. This happens enough that it's a halting concern on taking it anywhere serious.
3. If I tune the carbs to idle at 1500 RPM or so, I'll get a phenomenon where when idling in neutral, or holding the clutch in when in gear, coasting towards a slowdown, the engine's RPM will drop (this is all usually > 25mph), and then it'll just die right under me while riding. Thus, I'm running it high on RPMs right now to keep it from doing that.
4. Left carb leaks a little bit of fuel when shut down but only after the engine has been given time to cool down (don't worry, I typically close the petcock when leaving the bike for any period typically, I'm just taking notes under all circumstances).

Given my limited knowledge, the checklist I'm putting together looks a bit like so:

1. Verify float tanks are precisely in position at 21mm when held at a 45º angle
2. Check to see if gas cap allows air to bleed in as engine draws fuel (how does one verify this?)
3. Verify .... other non-intake-boot gaskets that I have yet to learn about
4. Adjust cable adjusters on top of carbs potentially?

Anyone have thoughts about these results? Any things to add to the checklist? Other exciting news is that it passed its (obviously not particularly stringent) inspection which means its one step closer to being out on the road on the regular!
 

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Discussion Starter #3
66Sprint and I talked last night and he impressed upon me to investigate spark plugs - I pulled them this morning before heading to work, and bought new ones on the way to my office. Will install them tonight, but here's a sneak peak of what the installed plugs looked like: https://imgur.com/a/zgbvn4I - looks like an excessively rich condition to me...
 

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Sensei
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Those are RESISTOR plugs (Big RED R)..... plus you have resistor caps...... This isn't helping the engine's running......
 

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Discussion Starter #5
Swapped out the resistor plugs with compatible plugs listed over at 4into1.com this afternoon - much much closer now! Can hold an idle around 1,300 instead of ≈2,000. Next up is carb tuning and replacing o-rings on intake boots with OEM parts later this week!
 
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