1990 90hp driveshaft sticking

[cfinke2002]

Went to start the motor this spring and starter wouldn't turn the flywheel. Checked batteries and connections - all good. Pulled the plugs and tried turning the flywheel by hand and could only do it using two hands with a lot of force.

Dropped the lower unit and still could not turn the driveshaft. Flywheel spins easily without the lower unit attached. Prop turns freely in neutral. I engaged both forward and reverse on the shift rod and tried turning the prop to see if that turned the driveshaft. It did, but it took both hands to turn the prop.

So, I pulled the water pump cover off and bamm, the driveshaft could be spun easily. There was alot of resistance coming from the impeller against the base plate. Tried to take the impeller off but it was seized to the driveshaft. Had to cut it off with a dremel. The impeller was still in good shape. I replaced it last year and didn't have this problem.

Drained the gearcase and found the oil very dark (darker than usual), but with no water or metal.

Ordered a new OMC water pump kit and installed. Upon tightening the water cover, I noticed the driveshaft becoming difficult to turn again. For kicks, I put the LU back on and have the same problem.

The boat was running great at the end of the year last season. Trying to figure out what the problem could be and to see if I could fix it myself, considering the marinas around here aren't taking work off the street.

Is it possible the driveshaft could be slightly bent, causing a problem only when the impeller cover is tightened down? How does that happen? Is there anything else I can check?

Thanks for your feedback.

 

[racerone]

Fact----It takes an amazing amount of effort to turn a water pump !-----Some will argue but I suspect you need to have your battery load tested.---And perhaps a NO MONEY spent tear down cleaning , lubing , inspection of brushes of the starter needs to be done.

 

[cfinke2002]

Thanks Racerone. Fair enough. Starter and solenoid were replaced less than 2 years ago, so I'll bring batteries in to be load tested first.

 

[cfinke2002]

Had the batteries tested and both were good. Since starter is only a year old, anything else I should check?

 

[racerone]

Well.-----I would not hesitate to pull a starter apart for inspection / testing.------A new factory starter or something else ?----Check battery cables too.

 

[tblshur]

i would use good jumper cables go from a running pickup straight to starter , are you using muffs or boat in water be careful hope you get it

 

[cfinke2002]

I had put one of those Sierra starters in. Theres a story there. I replaced the starter and solenoid last year before I realized my rectifier was shot (that was confirmed by testing the diodes). Both starter and solenoid were Sierra brand. The new solenoid failed almost immediately and I replaced it with an OMC. I wonder if I should have gotten an OMC starter as well. We'll find out.
The muffs make me nervous. I always feel like they dont fit well enough. I run the motor in the driveway in one of my wife's rubbermaid totes filled with water.

 

[racerone]

When testing in a tote the water level MUST be 6" above the pump !

 

[jakedaawg]

If you fried a new solenoid I am guessing you have either got high resistance somewhere, original battery cables maybe, or a high load, improperly installed pump assembly...just basing this off the solenoid comment. Battery cables dont last for ever and wingnuts are for Detroit hockey fans only.

 

[cfinke2002]

I feel like an idiot. Thank you all who steered me towards the battery/starter issue. Found the 12v power nut on the starter loose. Tightened and started fine. I was so convinced it was something bigger that I ignored the obvious. Let that be a lesson to me and everyone else tinkering with these motors.

 

[cfinke2002]

When testing in a tote the water level MUST be 6" above the pump !
I didnt realize this. Thought that as long as the intake was below the water level I was good. Then what's the difference between muffs and a tote with water above the intake?

 

[harringtondav]

When testing in a tote the water level MUST be 6" above the pump !
I didnt realize this. Thought that as long as the intake was below the water level I was good. Then what's the difference between muffs and a tote with water above the intake?

Impeller pumps are not self priming. Muffs force the water through the intakes and prime the water pump. In a tote or floating the water pump fills itself, as long as the motor is deep enough to submerge the water pump.