took it ta get scanned,found nothing. checked compression and was good 150psi. pulled out injectors and sent them to get cleaned.
buy the way had 3 cyclinders not working thats why we pulled out the injectors and mechanic says they were clogged.
will keep you guys posted once i put them back in.
thanks to all who were helping me out.

problem solved. Fuel injectors were the problem. got them cleaned, installed and all is good. Will do a run on Saturday and see if the engine will go over 4000rpm.

If the injectors were dirty versus failing then you better carry some extra fuel filters and change them often until you know there ain't more junk coming down the line to clog them again.

Aluminum tanks in boats often present lots of issues. Especially when there is a little water laying under our around them but you have no way of seeing it or drying it out...

Ugly. I wory bout it often as I rinse my cockpit out and live in a damp area .....

ran boat yesterday and all was perfect,both engines at 4800rpm. thanks to all.