RD350 Clanking Sound - see video!

[LexPaul]

Good morning,

Check out this YouTube link and take a listen. Thanks up front for any thoughts. I don't want to start pulling things off until I have an idea of where to begin.

https://youtu.be/VVEdb2lLIJk

I've got an irritating clanking sound coming off the RD350. I hear it mostly at low rpm. At 5000 & 6000 rpm I do not notice the sound or the misfire. The bike was running perfect 1000 feet above sea level. I am now at 5000 feet above sea level and it was running rich. I changed the main jet to 135 and the plugs look great, it'll run up to red line no problem, but all this time, before and after jet change, it's been clanking and acts like it's hopping down the road a bit when decelerating. It'll stop running at a redlight sometimes? I think the problem may be on right side?

It's got new cylinder, pistons, rings, dyna ignition, oil pump is spot on. Plugs look perfect brown??

Have a nice week.

[rodneya]

Cant help with the clank, but the surging on deceleration and dying at idle could be lean on the pilot circuit. going richer on the airscrew may help the surging, or you may need to go up on your pilot.(or clean / replace them if that are partly plugged)

[1976RD400C]

Taking a guess, it's not a mechanical problem, more like a lean pilot circuit or timing is off.