Merc 120hp hesitation question

[bryanmilio]

Okay...Its a 16 foot bowrider with the 120 merc i/o...When i put it in WOT it hesitates randomly...Two things occured right before this started to happen...I hit bottem but prop looks okay, and there was a pretty bad rain storm overnight...Could this be a prop problem, could it be water in the fuel? I plan on putting in some dry gas today either way.
Thanks

 

[bryanmilio]

Re: Merc 120hp hesitation question

anyone?

 

[ryanr623]

Re: Merc 120hp hesitation question

Okay...Its a 16 foot bowrider with the 120 merc i/o...When i put it in WOT it hesitates randomly...Two things occured right before this started to happen...I hit bottem but prop looks okay, and there was a pretty bad rain storm overnight...Could this be a prop problem, could it be water in the fuel? I plan on putting in some dry gas today either way.
Thanks

Sounds like it's fuel related, not sure how water would get into the fuel from a rainstorm, even if not covered, you have a doghouse. Try cleaning your carb.

 

[bryanmilio]

Re: Merc 120hp hesitation question

The gas cap assembly is a little suspect...but i did the dry gas thing...no change...but I did notice that when you turn the same way the prop spins fine...when you turn the other way or go straight (putting more pressure on the prop) it hesitates...I'll change out the prop and report back.
Thanks

 

[bryanmilio]

Re: Merc 120hp hesitation question

Update...

Now the outdrive won't go up...Is it okay to force it up by hand?

 

[lcmains1]

Re: Merc 120hp hesitation question

Okay...Its a 16 foot bowrider with the 120 merc i/o...When i put it in WOT it hesitates randomly...

Sounds like the accelerator pump in the carb is going bad. You most likely need to rebuild the carb.

 

[Bondo]

Re: Merc 120hp hesitation question

Update...

Now the outdrive won't go up...Is it okay to force it up by hand?

Ayuh,.... Sure, but I doubt yer man enough to move it...
Probably easier to Fix the trim pump...

It also sounds like the carb needs to be Rebuilt, 'n the fuel system sorted out...

 

[bryanmilio]

Re: Merc 120hp hesitation question

Thanks guys...

Got the trim to work...turns out the fluid was low and most likely has a slow leak...My prop is pretty chewed up so I'll swap that out next...Problem is, the boat is at my brothers dock and it would be alot easier to swap the prop while it's in the water...Do people do this? Also, how can I tell what Diameter my prop is? I have the serial number for the outdrive if that helps.
Thanks guys and sorry for all the questions

 

[lcmains1]

Re: Merc 120hp hesitation question

Thanks guys...

Also, how can I tell what Diameter my prop is?

You need to measure it. There will also be the specs stamped inside the hub of the prop.