powerhead replaced, seems like its binding

[MAW31]

replaced a 1995 88 SPL powerhead with a 1989 88 SPL powerhead.

prior to installing the replacement, the new powerhead turned over nicely with the plugs out while we got compression numbers. (125-127 compression across cylinders).

using the same starter which always cranked over my orig powerhead easily, it just will not crank the new powerhead over when the spark plugs are in.

now...while the powerhead was removed and just the driveshaft to the prop was sticking out of the lower unit, even out of gear, i could not bare-hand crank the prop driveshaft. I didnt know if this was normal or not.

what could be causing the increased resistance level and in what order should i test scenarios.

a. unbolt powerhead and raise off driveshaft? for possible motor-to-driveshaft binding? when i lowered the powerhead onto the splines, it slid on just fine and sat squarely on the lower unit prior to bolting down.

b. open up lower end gears to inspect? I had boat on the water 3 times last week, without any hint of issue.

c. buy a new starter? (its 'new' 2 years ago) can a starter's torque be tested?

What would you look into first?

 

[fire7882]

Re: powerhead replaced, seems like its binding

I would pull the lower unit and see if it would turn over better. Don't let it start because it wouldn't be getting any water.

 

[fire7882]

Re: powerhead replaced, seems like its binding

Also put the battery on a charger overnight or jump it to make sure your battery isn't going out.

 

[Chinewalker]

Re: powerhead replaced, seems like its binding

I'm pretty sure there was a change in driveshaft and crankshaft splines and how the driveshaft seal works within that year interval. Might be enough to bind things up.

 

[MAW31]

Re: powerhead replaced, seems like its binding

yep, the diff was that the seal is in a different location.

took the lower end off and bind went away. Actually, only until I sinch the screws tight does it bind. Almost the clearance of a gasket thickness.

I'm guessing if i grind off the top of the gearshaft a tad it'll be fixed.
or put a gasket in between the lower unit and mid section.

Once the bind was removed, the motor started right up.
thx all.