Topic: 3 cylinders and a hard start. high rpm or nil

[Lightning]

Following up my previous post; I was able to change the #3 spark plug. New and has spark. The #3 pipe still stays cold. I have to lean toward a carb problem. The PO said the bike leaked gas from #2 bowl and had them cleaned and fixed. I don't notice a leak. They are clean I have checked, though I know very little about carbs. The reason I am leaning toward a carb issue is that this bike is very hard to start. If it turns over, only on full choke, it revs very high, if i back down on choke or throttle it dies. I'm sure the carbs were never synced. I will buy the gauges and equipment to synch them if I can figure them out a little better.  ???Can anyone point me toward a resource to educate me on the carbs. So I know what is what and what to look at that may pinpoint a problem with the bad starts or cold #3. The manual that is linked on the forum is not as thorough and pictures aren't so good. 1980 CB650C

[xenoscr]

Have you looked in the FAQ section? There is also a very good carburetor manual in the tech section of the main page.

http://www.sohc4.net/index.php?q=node/65

XeNoSCR

[Terry in Australia]

It sounds like your pilot jets are blocked mate, that's why it won't idle with the choke off. Common fault, just pull 'em out and give 'em a clean, (you should be able to see a pin prick of daylight if you hold them up to the sun) then remove your mixture screws, squirt some carb cleaner up from your pilot jet orifices (with the jets still out) then replace the jets and screws (use 1 and 1/2 turns out from fully screwed in as a base figure on your mixture screws, then fine tune them as necessary) and see how it goes then. Don't bother syncing them yet, that's not your problem. Cheers, Terry.

[Lightning]

Thank you. i will pull the carbs tonight and get that manual downloaded. i love this forum.