low rpm

[SamLin]

my 1987 bayliner at wot will only get up to 3500 rmp and will not get boat up on plane . when not under load the rpms will go up to 5000 . boat has ne fuel pump filter carburator and has had the ignition changed to electronic ignition . any ideas as to what my problem is. please help

 

[isimar]

have you checked the exhaust port to make sure it's not plugging up ? had that happen to the motor on my pontoon.

 

[southkogs]

What prop are you runnin'?

 

[smokeonthewater]

Test compression and ign timing on engine.... Also make sure that the throttle actually opens fully when you advance the lever all the way ( check with engine OFF).....

As mentioned above what prop? Pitch? Condition?

 

[smokeonthewater]

Also WHAT 87 bayliner? What engine? What drive?
Fresh gas or old?