Did I blow the engine? 97 SeaDoo GTX?

Question

I thought I just fouled the plugs but I pulled one out and it had what looks to be aluminum on it. I replaced both of them and it still isn't running right. How much does a replacement engine cost for one of those? It's a 2 cylinder.

Answer 1

Aluminum transfer on spark plugs is bad news...you melted a piston.

Pull the cylinder head to assess the damage, if the cylinder wall isn't scored up too bad, might can be rebuilt.

Testing the overtemp warning horn should be part of your annual maintenance regime.

Answer 2

A "top end overhaul" would probably get it back up. The Rotax is a fairly simple machine to work on.

This site is a good source for repair parts and complete engines;http://www.sbtontheweb.com/Merchant2/mer...

The Rotax cases are pretty much bulletproof, so a piston  replacement may be all you need. You will have some wall scoring, so look into the cylinder exchange avenue at SBT, or the Top End Kit. You can have your cylinder bored locally for about $50.00.

Consider running a pre-mix fuel. SBT will reccomend that as well if you buy their engines. Also, check the exhaust valves for excess build up and proper operation. They can cause piston ring siezure.