valve clearences on srx400

[guest668]

having just rebuilt top end of engine we set valve clearences to 3fal with dot lines up with the t on crank.  started engine but sounded really rattly...on inspection oil pressure was good and getting to the head but valve gaps had increased.  has anyone got experience of this...could the cams themselves be the problem and also am i setting the gaps correctly am wondering if 400 clearences are different....can i check state of cams without lifting head off again.
many thanks

[Steve Lake]

Set the engine to TDC (if in doubt, pull the plug out, stick a pencil down the 'ole, turn engine 'til pencil stops moving up) use the 'T' mark on the flywheel viewed through the inspection port. need engine at TDC on compression, you'll see  inlet and exhaust valves are closed. then set inlet to 3 thou and exhaust to 6 thou (same as srx6) these are median settings... book quotes 2 - 4 thou inlet and 5 - 7 thou exhaust.

these are the settings i use, and work well.... but these engines arn't the quietest even when everything is set correctly, mine quieten down when warmed up.