01-10-13, 10:45 PM
I doubt insurers would be interested in dyno numbers, they will only be concerned with manufacturer quoted horsepower when new. A dyno only gives a figure for any given moment in time; he could have done anything to the bike afterwards; if you have any doubts I would get clarification from the DVLA. If you get it wrong you'll likely end up with 9 points and nasty fine.