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Half Throttle When In Gear

T

Trip5981

New member
Any ideas are greatly appreciated. I am new to I/O motors. Recently bought a boat with a 454 Merc. The boat sat for 2 years prior to me having it. Ran a sea trial today and when in gear I only get about 3000 rpms, If i just work the throttle via the button on the side of the controls I can get 5000 or probably more.

All new fuel, the motor runs smooth and idols great so I'm not thinking its a fuel problem. I'm thinking more like shift cables but before I go that route I figured I would ask if anyone has any ideas.

What could be holding the motor back when in gear?

Thanks in advance for any suggestions.
 
could be a transmission problem , bent shafting, bent prop ,I dont know.
Also dont know what your working on either
But the 454 can run perfectly with the #5 and #7 plug wires reversed and 2 non firing cylinders
 
First check your firing order, like Bt Doctur mentioned. Next your timing, to have a point to start from. Please don't overrev your motor in neutral, it's not good for the rings primarly, and all other engine parts. No more then 1200-1500rpm on the muffs either. Check to see (with engine off) if the carburetor is opening fully with the helm controls, or if the control cable needs adjustments? Start with these items.
 
If i just work the throttle via the button on the side of the controls I can get 5000 or probably more

What button are you referring to? the trim button? Do you know what this button does when not running the engine?
 
The control button is for starting, & running your motor without engaging the drive At all, you push it in only to start, & run the motor without any driveshaft engagement. Moving the lever back to neutral idle position, the button will pop out, then just shift into gear, forward, or reverse, to move on with gear engagement. Right now it sounds like you've been revving the motor to 5000rpm in neutral!

Okay now Button in (Neutral), Button out (In Gear) got it?
 
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