550 valve clearances closing up after engine rebuild

[bigmockuk]

can anyone tell me if its natural for the valve clearances to close up on a cb550 rebuilt engine,this is my first 550 and after working on it for over 8 mths its finaly running! what a buzz it was on sunday to hear it run but...only no1 cyl was running properly and others were missfiring.later found out carbs were not seated properly on stubs and 6 valves had closed up.no1 was very smoky so i stripped head off it thinking i had forgot a valve seal as found a spare in the gasket set i got but all was fine.rebuilt it up and wow it ran great.after ten mins going round garage area it stopped as if fuel ran out and would not start but turns over,i think valves may have closed up again will check later today.no1 does not smoke at all after rebuild and all 4 fire fine.this is this vid of it running on sunday albeit rough then...https://youtu.be/NbyrdmwpQfc.will upload yesterdays vid later today

[Bryanj]

Not normal but if you did not heed the manual on cover replacement you may have bent valve stems and/or broken guides

[bigmockuk]

Hi Bryan i used elastics to hold rockers up and all was ok.had bike running on all 4 yesterday and ran fine apart from no3 being a bit loud due to almost hollow!.i felt it was overheating quite a bit after 10 mins of running around garage area but thought it may be due to black enamel i used.im on my way to check on things as i speak starting with valve clearances so i`ll keep you posted on my findings,cheers for the reply.that vid of the bike running on sunday should have been https://youtu.be/NbyrdmwpQfc

[bigmockuk]

Well, was happy to find none of the valve clearances has altered! dont hnow why it cut out yesterday,drained all float bowls and it fired up after a few attempts.only thing im slightly concerned about is the overheating but may be due to weak mixture,i have the mixture screws set at 1.5 turns out.oil light goes out soon as it starts too.