Max rpm 4000

joed

Lieutenant Junior Grade
Joined
Sep 28, 2002
Messages
1,135
1995 Mariner 60 3 cylinder
It won't run above 4000rpm. At idle and below 4k it runs as normal.
I have changed the plugs.
I took the boat out today and ran some tests.
1. Idle only goes up to 4700 at full throttle.
2. Running reverse, same results as running forward. 4000 max.
3. Disconnected spark on each cylinder one at a time. Engine would barely run each time.
4. Switched to portable gas tank. No change in performance.
I am wondering if it could be the ignition module? I had to change it a couple of years ago when it completely failed.
I haven't done a compression test yet. My tester is at home. I am at the cottage.
 

joed

Lieutenant Junior Grade
Joined
Sep 28, 2002
Messages
1,135
Do you think there is any issue if I continue to use the engine at the lower max rpm?
 
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