Well, found number 2 coil is bad, the photo shows it next to a good one . Talked to BUP yesterday and he said it's called a secondary post failure https://cimg6.ibsrv.net/gimg/www.off...91b3afb43d.jpg

One of my 525s has developed a misfire over the winter. I fired it up last weekend, and idles fine, but won't rev properly. Getting to the coils is a b#tch on my boat, not looking forward to diagnosing this at all.

E32,
It's not easy that is for sure.....
Good luck with it, the easy way to find out which cylinder is misfiring is just fire up the suspect engine for about 1 minute, and just feel for the cold header runner....

I got lucky. Once the engine warmed up, it ran fine. I'm not sure how it was winterized, but after a few minutes on the hose, everything was fine. Then I took the boat to the lake, and everything was still fine. Feeling for the cool runner is a great tip.

Prob was a tad of condensation in your fuel very common from lay up... All the fuel filters need to be changed at the spring commission and that fuel examined ? and fuel samples from the gas tank(s) are very recommended about 3 times per year min especially at layup and start of boating ?

Coil replaced and misfire is gone, thanks BUP!