69 25hp evinrude prop shaft binding up.

[54bobby]

so, last year i ran the 25hp lower unit on my 68 18hp fastwin. reinstalled it on the 25hp and when i tighten down the skeg screws, the prop shaft binds to the point that it is barely turnable. loosen the screws and she spins freely, at this point there is no torque on the screws at all. there is a spot in between tight and lose where if i spin the prop, every 1 revolution in the same spot it binds and past that spot turns free till returning to that same position every revolution.i have access to a flat surface but not till monday. don't know where anything would have gotten bent but will certainly check, is there anything else that could cause this condition? she was resealed 2 years ago along with both impeller and pump housing,

 

[racerone]

Does it have the original bushing or the updated needle bearing ?------If original is the pin on the front bearing properly lined up ?

 

[F_R]

I would say the prop shaft is bent. But really, how would anybody go about bending one?

 

[F_R]

Possible wrong drive shaft (too long)?? Or drive shaft not going all the way up into crankshaft splines? Either of these situations would mash downward on the gears in the lower unit. OK, just educated guesses.

 

[54bobby]

Possible wrong drive shaft (too long)?? Or drive shaft not going all the way up into crankshaft splines? Either of these situations would mash downward on the gears in the lower unit. OK, just educated guesses.

not the wrong shaft as this condition was detected before i even installed the shaft.

 

[54bobby]

Does it have the original bushing or the updated needle bearing ?------If original is the pin on the front bearing properly lined up ?

if you mean the little pin that sits in the hole in the front bearing, then yes, it is seated properly. the rear bearing was crushed in flat as i've heard happens from misassembally but i drilled a new hole and installed new pin. when assembled shaft is seated, she's flush and seams to be as it should. if that rear pin was seated just a hair to high, could that make everything seam ok but when torqued down cause this condition? as of now, the original equipment pin on the front bearing is protruding a little higher than the rear. are they both supposed to be the same height? reason i ask is i originally had the rear the same height but the shaft wouldn't seat properly so i sunk it till she seated what i considered to be the correct depth.

 

[54bobby]

Does it have the original bushing or the updated needle bearing ?------If original is the pin on the front bearing properly lined up ?

by original bushing, what bushing are you referring to? and what updated needle bearing?

 

[F_R]

He is referring to the big flanged bushing on the forward gear.

I dont think the locating pins are the problem. If they were mis-located or sticking up to far and mashing the bushing, the gear might be tight. But the prop shaft still ought to spin freely within the gear (in neutral).

 

[racerone]

The pin locates the bushing to get proper oil flow in the bushing.

 

[Tim Frank]

is this rig trailered or moored?
easy to tweak alignment with a bad launch experience.

 

[54bobby]

is this rig trailered or moored?
easy to tweak alignment with a bad launch experience.

trailered but never bottomed out.

 

[54bobby]

went to one of my parts engines and removed the prop shaft and gears. swapped out the rear brass carrier. my original didnt slide on real smooth. same thing with the parts engine carrier. examined both and found that each had that pin crushed at some point and that made a high spot on the inside of the brass carrier. with either one on the shaft there is a binding oncr every revolution. off to the basement for another and found one made from stainless. slid right on w/o any binding. will reassemble today and report back. hope this solves it.

 

[54bobby]

SOLVED;
When i drilled the new hole to relocate the rear carrier locating pin, i drilled it to shallow. that's what was causing the binding.

 

[54bobby]

Can anybody post the exact depth of the whole or the height it protrudes from for that PIN for the rear carrier