help!!

[CB Rider]

Hey Folks, first post from Canada. I have a 1980 750K with 65,000 kms on it. This spring I've started to here a repetitive ker-klunk sound when accelerating in first gear, once my speed gets over 15-20kph it goes away or becomes indistinguishable from the rest of the engine noise. Any thoughts on what it could be? Have already asked else where only to have the question hijacked by bad fuel/ignition knock debate that was of no help. Clutch rattle maybe? I'm new to riding full time but want to learn how to work on the bike myself and i'm willing to put in the time.
Any thought/ideas would be helpful and appreciated.
cheers

 

[dirtdigger]

What condition is the drive chain and sprockets in? Have you lubed and checked it for stuck links?

 

[CB Rider]

Thanks dirt digger. Opened up the bike to get at drive socket, figure'd that would be my best bet at finding frozen link and... well duh, what a mess. chain dirty and sticky, cleaned lubed and tensioned and now quiet. As cyclist ya think I could have put 2+2 together?? Looking for zebras when I was hearing horses.
What is the deal with the carbs? that you mentioned in another post. All makes or just those sold in U.S. I thought I read you guys got a different set up Than ones sold north of the border

 

[dirtdigger]

All of the CV carbs are junk. They are very sensitive to air flow. These came about when fuel economy was more important than how well it ran. Same thing happened to cars when they tried to make carbs computer controlled...what a mess...I am glad those days are done. The carbs have issues when modifying anything...air box, exhaust, bigger displacement, cams etc. They dont like modifications....if you leave everything and I mean everything stock then you can get by with them.

 

[6Blackie6]

I've put a 4-1 exhaust on my '80 750K and re-jetted. I love the Keihin carbs. Easy to work on and clean. Runs fantastic! Still not going to remove the air box though haha. Not quite that brave!