[Cb400norway]

Hi all!

recently put my engine back together after changing headgasket and the lower engine gasket. I also removed carbon from my pistons and grinded the valves, and changed the valve stem gaskets.

so fast forward, putting the engine together goes nice, connect some fuel and on the second try it fires right up! (Happy!!)

But I heard this noise, which I first believed was the cam chain, so I loosen the tensior bolt as per the manual and let the automatic tensioner do its thing. But I still hear this noise? What could it be?
I used a screwdriver to listen to different parts of the engine, and it might sound like its coming from the lower part, it sound «deeper» down there and more like kinda a light rattle at the valvecover.

I have attched a video of the bike running. Any help will be much apperaciated!


Engine sound

 

[DD23]

You know of CMSNL, research the balance chain system.

The slotted plug on the clutch cover at about 1 o clock....remove and have a look in there.....

You will see a 12mm nut sitting in an arm's " slot".

This arm or quadrant has a 14mm nut attachment to the balance shaft.

Slacken the 12mm nut, the arm should automatically rotate anticlockwise ( spring loaded but may need "exercise" ) and auto adjust. Tighten 12mm nut.

Do all this with the engine OFF, not running !!!!!

Is there any slot left now ?

Over

 

[Bill H]

I agree with drydreamer. Question did you grind the valves or hand lap them ?. The valves only have .002 of hardened material on the outer edges and you may have removed it. The motor will run ok but there will be less time between valve jobs . The valves may have a different sound . Since you have had the motor running I would also reset the valves. Just a thought.

Bill H

 

[Cb400norway]

Will give this a try, I just saw a video on youtube where someone did this job.
I did hand lap them, with fine grinding material, I feel I did not overdo it. Thanks for the advices👍