Purchasing new SeaDoo Spark vs. used SeaDoo (2007-2010ish)?

I am interested in a new jet ski. I already have a 1989 Yamaha Waverunner on a large lake. I am interested in either purchasing a new SeaDoo Spark or a used SeaDoo (2007-2010ish) on Craigslist. Used option would usually be a little cheaper. Which is the better option? Thx

First, remove the gear case (lower unit) to determine if the problem is engine or gear case related. If the crankshaft still will not revolve with the gear case removed, the problem is engine related, and will require complete dis-assembly to diagnose and repair. If the crankshaft rotates with the gear case removed, the problem is in the gear case. You should probably invest in a manual before attempting any major repairs.
http://www.marineengine.com/parts/part_d...

BTW, your outboard is a 1982, not 1983.
------------- You should also be able pick up (or order) the service manual at any BRP/Evinrude dealer in Australia.
Another quick check you can do- remove the spark plugs, and using a piece of stiff wire, check for movement of each piston as you rotate the crank. This will at least tell you if you have connecting rod damage.

An Icon of Saint Nicholas , patron saint of sailors .

It all depends what sort of boat and where you are boating in it .

Obviously , an inflatable toy dinghy on your local pond will require far less safety kit than a 50 foot sailing yacht doing a transatlantic voyage . You need to repost a question detailing all that before you will get intelligent answers .

if the motor sounds like it's revving OK then you have a slipping coupling betweeen the motor & the jet unit.
If thr motor doesn't rev out but sounds bad then you have an issue with tune or a damaged motor.

A 1.5kg squid can accelerate at 20 m/s2 by ejecting 0.15kg of water.?

What is the magnitude of the thrust force on the squid?What is the magnitude of the force on the water being ejected?What acceleration is experienced by the water?