J3 engine noise, low end ?

Hi! Got my bike running but i think it sounds very mechanical...
The noise is a short of rattle when the engine is idling but disappears when reving. I'm not sure if you can hear it in these videos, it's from my first start up and from later the same day.




I'm running a stock engine with Mikuni RS34's, K&N pods and a Mac exhaust. The carbs have NOT been tuned and after installing Dyno ignition i adjustet the timing roughly with a timing-gun/light. I've read about non-tuned engines rattles but what else to look for ? I will take the bike apart this winther (i'm in Denmark) and change the cam chain and install a manual cam chain tensioner. Any bearings i should be looking for ?


Simon

Bike in the first video isn't combusting on all four cylinders.

Could spray water mist on the exhaust headers just after starting the cold engine.
The mist will instantly sizzle and evaporate off headers from combusting cylinders.

A good tune-up, including carb sync, usually reduces valve train noise, even on engines that are combusting on all four cylinders.

Good Fortune!

So you don't think there is anything wrong? But it's never a bad idea to change the cam chain right ? And i can even do it without removing the head ?

Simon

Patton wrote: Bike in the first video isn't combusting on all four cylinders.

Could spray water mist on the exhaust headers just after starting the cold engine.
The mist will instantly sizzle and evaporate off headers from combusting cylinders.

A good tune-up, including carb sync, usually reduces valve train noise, even on engines that are combusting on all four cylinders.

Good Fortune!

Yeap I agree it's not firing on all four or very poorly on them. Syncing the carbs will reduce engine noise so it's not struggling and fighting itself. Pulling clutch in sometimes will slightly reduce noise.

Mk2Rookie wrote: So you don't think there is anything wrong? But it's never a bad idea to change the cam chain right ? And i can even do it without removing the head ?

Simon

Not yet suspecting a worn cam chain in this instance.

A good competent complete tune-up would likely resolve most if not all the issues of excess mechanical noise and rough running.

In it's current state of tune, even with a brand new cam chain, the engine would probably run just as noisy and rough as it's doing now.

Good Fortune!