Rev spike when starting up

[th365thli]

This is probably a stupid question. I have a 1987 2 stroke Yamaha Pro V 150. I recently had to adjust the timing within spec to fix what the previous owner did. It seems to idle better, but I notice that when I turn the key to start it up, the revs jump up really quick, before quickly settling down to normal rpm.

This is normal correct?

 

[99yam40]

It is a carbed motor, so either the throttle plates are bot closing properly for some reason or the timing is advancing to increase the idle RPM.
did you follow the link and sync procedures in service manual for setting linkages and timing?