Originally Posted by
AndysF3S
I'm in the same time period and my SWAG is the piston had failed when the dealer said there was no compression and putting new plugs in, was a way out without an engine tear down. A 3 cylinder will run on 2 cylinders and it looks like it was run after the damage until the piston damge lost a big enough piece to stop the rotation. Just an opinion but doesn't matter at this stage.
I have not replaced an engine in a Spyder but I am wondering if the OP should see if the engine comes with the ECM just in case there is a some difference in programming between the donor Spyder and his??