Mag 350 won't rev above 3600rpm

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Hi all,

So, 5.7 Mag 350 won't rev above 3600 rpm.

Story goes all running fine until we noticed a water leak in the fuel cool, goes into mechanic and we need a new fuel cool and fuel line. All the work done and today was the first time out on the boat since, started fine, ran fine in the speed limited harbour, we get on the plane about 15 knots, accelerate and it misfires badly about 18-20kts. We come straight back in as the harbour exit is busy shipping lane. At the marina, put into neutral and sure enough won't rev past 3600. The mechanic was about and seemed to think it was a blocked airfilter, it was fine prior to the work. Any thoughts?

I've got the airfilter off and back home now so will try that but doesn't sound right to me.

[fester]

I literally just went through the exact same issue.
https://www.maxumownersclub.com/foru...rpm-11088.html

An engine tune up with a new distributor cap, Rotor, spark plugs, cables and powertune can fixed my issue.

Could be fuel starvation too.

Hope this helps

[mmwjr]

Since it won’t go over 3600 in neutral I would think the ECM rev limiter is kicking in. I believe the cool fuel module is on the same side as the knock sensor, maybe he damaged it accidentally.