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Hi- I'm a newbie.
Launched boat this year after winter storage at dealer. Motor will not rev above 3000 rpm; and shakes badly. Seems to start and operate o.k. below that limit.
Bought the 2004 Johnson Service manual for the 50 HP 4 stroke 4 valve EFI. While there are no warning horns or alarm lights in starting system on startup, the symptoms are consistent with the engine CAUTION system being triggered somehow.
Low oil level?-Checked oil level- full and clean.
Overheating?- Checked the water flow- good cold stream coming out of the outlet.
Cylinder head temperature sensor? Disconnected temperature sensor and started motor- check engine light came on and horn alarm sounded; still won't go above 3000 rpms. Reconnected and check engine light did not come on, nor did alarm sound; but still would not rev above 3000 rpms.
Exhaust Manifold Temperature Switch? Disconnected temperature sensor and started motor- check engine light came on and horn alarm sounded; still won't go above 3000 rpms. Reconnected and check engine light did not come on, nor did alarm sound; but still would not rev above 3000 rpms.
Willing to continue, but at a loss as to what to try next- don't have electronic diagnostics skills, but could probably get and figure out an ohm meter. Reluctant to haul it all the way to a dealer if it is something I can easily fix.
Suggestions?
Launched boat this year after winter storage at dealer. Motor will not rev above 3000 rpm; and shakes badly. Seems to start and operate o.k. below that limit.
Bought the 2004 Johnson Service manual for the 50 HP 4 stroke 4 valve EFI. While there are no warning horns or alarm lights in starting system on startup, the symptoms are consistent with the engine CAUTION system being triggered somehow.
Low oil level?-Checked oil level- full and clean.
Overheating?- Checked the water flow- good cold stream coming out of the outlet.
Cylinder head temperature sensor? Disconnected temperature sensor and started motor- check engine light came on and horn alarm sounded; still won't go above 3000 rpms. Reconnected and check engine light did not come on, nor did alarm sound; but still would not rev above 3000 rpms.
Exhaust Manifold Temperature Switch? Disconnected temperature sensor and started motor- check engine light came on and horn alarm sounded; still won't go above 3000 rpms. Reconnected and check engine light did not come on, nor did alarm sound; but still would not rev above 3000 rpms.
Willing to continue, but at a loss as to what to try next- don't have electronic diagnostics skills, but could probably get and figure out an ohm meter. Reluctant to haul it all the way to a dealer if it is something I can easily fix.
Suggestions?
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