So, I've read through this thread like, 4 times searching for the year model of your boat. The only 2 real things I believe I've been able to figure out by process of elemination is:
It is a boat with a 4-TEC engine...
It is a boat with a relatively new 4-TEC engine in it.
The reason I ask is because of that one question. Root cause. Do you know why the motor blew up? If not, then what's to say this new one isn't going to blow up. Just taking out something broken and putting in something that works again doesn't solve the root cause as to why it broke in the first place.
The real reason for me to put my 2 cents worth is because you also make the statement that you had a dropped valve (supposedly).
I'm sure you know how much money these engines cost, you just bought one. Probably paid 1/3 of the price for the engine, the other 2/3 of the price for the jacking................sorry, paid it for the expert work for a dealers installation.
If you do some research, you'll find that Seadoo has had a problem with dropping exhaust valves, especially on the #3 piston, and blowing motors. When the motor is taken down, it's found to be from water incursion. This is not covered by warranty. If this happens to someone on a ski, they have to proove that they didnt' flip the ski. The boat?..........that would be a harder position Seadoo would have to say you ingested water.
If this motor was practically new, say 2007 or better, and you had taken care of it, got it serviced like you were suppose to, then why would you blow an engine or drop a valve?
A light mist of water vapor, from jumping waves or just the moisture content while on the water, is enough to collect in the air induction of the motor. When this moisture makes it's way into the heads and hits the exhaust valves, there is a potential for damage to the valve train, usually the exhaust valves are the only ones affected.
So, find out from the mechanic, which valve caused the engine to blow up. If it was indeed the exhaust and this engine isn't but a year or so old, I'd be on the phone to BRP looking for some answers. Unless you have $5K to throw away on anohter motor................:cheers: