Nasty engine rattle and vibration

Hey guys any thoughts on what would be causing an Nast engine rattle and vibration in my KZ 750m1 twin it comes and goes any thoughts from the team. I'm thinking I'm gonna need to totally rebuild the engine at some point and maybe sooner than I'd planned to.

Could you give us a little more info? Does it vibrate just sitting there as it idling? Is it when you are riding it under normal conditions? Is it when you are running it hard?

Just trying to narrow it down a bit. Did you clean the carbs and go through all the electrical connections so there is no electrical connectors that would cause it? Good plugs? What color are they?

Thanks

Have you adjusted your cam chain?

Synched the carbs?

When idling it comes and goes and if rattling on start up it goes when bike is put into gear. I'm going to try adjusting the cam today and I'll get back to you once I've done that. It doesn't seem to be a carb issue as it runs fine and starts well. I will pull the plugs today and check for carbon build up as well

I had one in my bay with a counter balancer problem. Do you have a manual?
Steve

Captainkiwi wrote: When idling it comes and goes and if rattling on start up it goes when bike is put into gear. I'm going to try adjusting the cam today and I'll get back to you once I've done that. It doesn't seem to be a carb issue as it runs fine and starts well. I will pull the plugs today and check for carbon build up as well

I'll defer to the gurus here; Steve has always been a good judge of problems from keyboard's reach.
BUT
This sounds suspiciously like what my '82 550a was doing when I first got it. Cold starts and random idles. I was thinking it was tied to the primary chain (think it's called this) inside which I understand is always in rotation regardless of final drive chain's actions.
On the 550a (at least I am under this belief) you cannot adjust or tension this chain and the cam chain is auto-magic...
Steve advised me back then to review my carb synchronization and when I finally did that and got the idle and choke dialed in, all that noise went away as he stated. I still rarely hear it when it's cold started (hasn't been run in days or longer cold...) but it's usually short duration until the engine warms up for a minute. This I've attributed to my skill, or lack of, at synch'ing the carbs the first time...

Just thinking out loud... It may have no bearing on your model.

It's been so long since I've worked on one. Hell that was back in 85. Every time I got a new bike in, I'd get the manual for it. They were all stolen when I had the wreck. Trying to work on a bike or anything for that matter without one is like groping in the dark.
Steve

Yeah, I agree Steve. Without even a picture to see or video to hear, anything is a gut-feeling-guess from hundreds or thousands of miles away but you have waaaaaaay more experiences to base even gut-feeling suspicions upon and you are very humble it seems.

Definitely, having the correct manual or even every manual you can find on your particular motorcycle is waaaay worth the time and cost to get them. In my shop, back in the day, we had a long shelf right there in the work bays with all the manuals for everything we worked on. They were all tattered around the edges and you could see at the sides where certain chapters got greasier than others. :laugh: and I for one was happiest knowing the manuals were actually being used by others too. In fact it was those times when a new manual would get added to the shelf; we'd take bets on how long it would be before someone would say "Hey! There's a new manual..." and who would be the one to say it. :laugh:

Do they make Chiltons anymore or am I just showing my age? :lol: :whistle:
Steve

Hey guys thanks for all of the great input ......I've tried posting video on here but nothing wants to upload .....I've asked to join the FB group and am just waiting to be added there and I will post up a video so those of you with a much deeper knowledge than I can put your well tuned ears to the issue at hand ......I've got the manual for the bike it's got all of the 79-83 for the 750 twins with supplements for the various models including my model the kz750m1 CSR .......so please if anyone who is admin on the Facebook page can add me ASAP I will get that video up

Also when riding under normal conditions

Have you tried uploading to youtube? That's what I do. I have the facebook page but it isn't used lately.
Steve