1994 Mariner 175 Mag... Help troubleshooting RPM loss/won't Plane

[stratos 284 dc]

1994 Mariner 175 Mag... Help troubleshooting RPM loss/won't Plane

1994 Mariner 175 Magnum
OD167689

Friends New Used Boat

I have only Evinrude and Yamaha experience and need some help

Motor is on a Skeeter 18ft

We took it out this spring and ran it.. got on plane a little slower then i expected but ran ok... got mid 60's out of it and 5900 RPM

He took it out over the weekend here and it has some issues now..

He said...

Unloaded it..
Started right up..
Got on plane with him and his old lady kind of sluggish..
Ran around for about 5-10 min
Idled and looked at houses for a bit
Went back to get on plane and motor wont go over 2200 rpm..
I seen a video of it...
From idle in gear goes full throttle and it revs to 2200 and just slowly falls off down to almost idle... not really a lot of miss or anything just falls off...
Revs up in neutral no problem
but wont under load

I went over yesterday with the muffs and checked somethings..

Started Ok


Fuel Pressure with key switch on is 37-39psi
Fuel Pressure running is about same

All cylinders with 10 psi of each other

Plugs are ok...
Spark to all cylinders..

Checked battery 12.7 not running
12.5 running??

So no charging voltage


Disconnect Stator wires from Blocks and Ohm'd it out.. i think i did it right positive lead to wire/ground to block

R/W 114
BL/W 3900
R 112
BL 4000

Stator was luke warm

Didn't test the DVA Or Trigger..

With no manual and no real older Merc experience i need some help

I know theres more fuel related things to look into and electrical testing

Just need Some friendly direction

[EuropeanAM]

Good starting point after checking basics:

FUEL LINES AND PERFORMANCE PROBLEMS

[runt4561]

im no expert by any means but I have had a similar problem that I have been trying to figure out for 4 years with these motors and from what I have learned most problems like this can be attributed to fuel line/filter or primer bulb, stator or ecu (my issue). the ecu seems to be most common if the issue is sporadic. if it is ecu, checkout brucatopower.com

[Jbunkley]

1994 Mariner 175 Mag... Help troubleshooting RPM loss/won't Plane

1994 Mariner 175 Magnum
OD167689

Friends New Used Boat

I have only Evinrude and Yamaha experience and need some help

Motor is on a Skeeter 18ft

We took it out this spring and ran it.. got on plane a little slower then i expected but ran ok... got mid 60's out of it and 5900 RPM

He took it out over the weekend here and it has some issues now..

He said...

Unloaded it..
Started right up..
Got on plane with him and his old lady kind of sluggish..
Ran around for about 5-10 min
Idled and looked at houses for a bit
Went back to get on plane and motor wont go over 2200 rpm..
I seen a video of it...
From idle in gear goes full throttle and it revs to 2200 and just slowly falls off down to almost idle... not really a lot of miss or anything just falls off...
Revs up in neutral no problem
but wont under load

I went over yesterday with the muffs and checked somethings..

Started Ok


Fuel Pressure with key switch on is 37-39psi
Fuel Pressure running is about same

All cylinders with 10 psi of each other

Plugs are ok...
Spark to all cylinders..

Checked battery 12.7 not running
12.5 running??

So no charging voltage


Disconnect Stator wires from Blocks and Ohm'd it out.. i think i did it right positive lead to wire/ground to block

R/W 114
BL/W 3900
R 112
BL 4000

Stator was luke warm

Didn't test the DVA Or Trigger..

With no manual and no real older Merc experience i need some help

I know theres more fuel related things to look into and electrical testing

Just need Some friendly direction

Did you ever figure out the problem? I'm having same issue