Motorcycle Repair: 1974 Honda CL200- Running One cylinder, CL200, carb


Question
Hey Bob, i have been working on a CL200 for a couple weeks now, and after cleaning out the carbs, my right cylinder has stopped firing. When i adjust the carb, nothing happens at all. A week ago it was working fine. So, i bought new plugs, but that didnt help. I checked the float levels and they seem to be set evenly on both carbs. I checked for spark, and got good results. Also, the pistons are moving on both sides, but the left side exhaust gets extremely hot immediately and the right side stays cold. to start the bike, i have to really enrich the fuel on the left side, seeing as the right does not respond to anything. Also, gas is flowing nicely to both carbs. Thats all i can say so far, do you have any ideas?

Thank you,
Mike

Answer
OK, what makes the exhaust get hot is burned fuel/air mixture passing through it, so it makes sense that the pile on the side that is running would get hot fast and the other side would stay cold.

Other than the carbs, the only thing that could cause this is a bad plug wire or something very wrong with the valves.
You can eliminate the ignition system completely by reversing the plug wires. If the problem stays on the same side it is not the ignition but if it moves it is the plug wire or the plug cap.

My suspicion, since the problem showed up after you "cleaned out the carbs", is that the problem lies there.
What is your definition of "cleaning out the carbs"? To properly clean carbs they must be removed from the machine, disassembled and have, at minimum, carb cleaner sprayed through every passage, followed by high pressure air (min. 60 PSI). Any signs of dirt or other deposits should be completely removed and all jets carefuly inspected and cleaned. Your carbs are 34 years old and that's a long time for rubber parts that have been in a hot place and in contact with fuel. The rubber parts should all be carefully inspected and if any of them show signs of hardening or deterioration they should all be replaced with the best quality new parts available. Even if they all look good now, you should expect to replace them within the next year or so.
Have a look at the carb cleaning information at www.randakks.com - Randall is one of the top GoldWing restorers and carb specialists so the site shows GoldWing carbs, which will probably be a lot different from yours so you should consult your shop manual, but the same principles for cleaning should apply.
Unfortunately, he doesn't sell the parts you need. I would talk to the parts man at my local Honda dealer before I looked for the parts anywhere else - they are usualy pretty close in price to what you would pay online and if anything is wrong with them you can take them back in person instead of dealing through the mail.

At any rate, even if you cleaned them as carefully & thoroughly as humanly possible the first time, you are going to have to go through them again. While you are at it, make sure that you haven't mixed up the jets (I'm not sure about the CL200, but other models have otherwise identical jets with different size holes - the sizes should be stamped on them somewhere).