a couple of MC I Outdrive questions

[stevenhickeys]

Hello,

Recently, I removed my L/U from my O/D to replace the impeller. I noticed the old impeller had some of the blades broken off and was wondering if these broken pieces could have worked their way into the motor block. My Starcraft American 20 has a 1976 165 Mercruser with a MC I outdrive. Should I worry about these blade pieces inside the block or could they most likely been flushed out of the system?

After removing the L/U, I also wanted to remove the upper section to take a look at the bellows and gimble. I removed the 6 lg nuts holding the upper unit, wiggled it and got a small separation where the gasket is, but I can't seem to get this Upper unit to come off. Is there some bolt, hose, or something else holding this thing on? I didn't want to start whacking it until I got some tips from the Pro's.

Thanks

SH

 

[ziggy]

Re: a couple of MC I Outdrive questions

Recently, I removed my L/U from my O/D to replace the impeller. I noticed the old impeller had some of the blades broken off and was wondering if these broken pieces could have worked their way into the motor block. My Starcraft American 20 has a 1976 165 Mercruser with a MC I outdrive. Should I worry about these blade pieces inside the block or could they most likely been flushed out of the system?

yep, ya should worry. when i had that issue. i flushed water from where the water hose connects to the t stat housing. water fwd's and backwards. my upper was still on like yours. i used a bucket to catch the flush water. i got bits and pieces of impeller that flushed from both ends. also take the tstat apart. i found pieces there too.

also might check your exhaust flappers. they likely melted during the over heat. ya might find them when ya take the upper off.

After removing the L/U, I also wanted to remove the upper section to take a look at the bellows and gimble. I removed the 6 lg nuts holding the upper unit, wiggled it and got a small separation where the gasket is, but I can't seem to get this Upper unit to come off. Is there some bolt, hose, or something else holding this thing on? I didn't want to start whacking it until I got some tips from the Pro's.

the helm needs to be in fwd too. this allows the shift shaft shoes between the bell housing and the upper to slide apart. which they need to slide or won't come apart. i assume ya get the trim ram pin out of the aft connection to the trim rams?

edit.
this pic is of a 75 165io. the helm is in neutral.

ya can see the shift shaft shoes pointing to port while in neutral. if the helm were in reverse, the shoes would be even further to port. however if the helm is in fwd. these shoes point fore and aft. allowing them to slide apart for upper drive removal.

 

[stevenhickeys]

Re: a couple of MC I Outdrive questions

Thank you Ziggy!!

I worked the shifter back and forth and left it in forward. I slowly got the upper off with a large screw driver and a pry bar. This upper had probably not been removed for several years so it took some TLC.

I need to have the L/U looked at because it had some water in the oil. I am hoping it will not need bearing and just new seals.

About the impeller blade pieces. I took the t-stat apart and did not find any pieces. I blew down the intake hose and a couple little pieces came out. There was a couple stuck right in the pump housing itself.

I guess I will wait until spring when I can put the whole sha bang together and see if any more pieces some out??

SH

 

[bspeth]

Re: a couple of MC I Outdrive questions

You can pressure test it and see what you are up against.

 

[wrench 3]

Re: a couple of MC I Outdrive questions

also might check your exhaust flappers. they likely melted during the over heat. ya might find them when ya take the upper off.

The in-line engines don't usually have exhaust flappers.

 

[ktbarrentine]

Re: a couple of MC I Outdrive questions

the helm needs to be in fwd too. this allows the shift shaft shoes between the bell housing and the upper to slide apart. which they need to slide or won't come apart. i assume ya get the trim ram pin out of the aft connection to the trim rams?

While it is always good practice to put the shift lever in fwd when removing the outdrive, in this case where the lower was removed first, it isn't essential to have the shift shoe pointing fwd, as the intermediate shift shaft will drop out of the slot when the lower is removed. However, when putting it all back together, always put it in fwd, and have the lower end shiftshaft rotated to fwd with the prop "locked" and held CCW with a bungie, to ensure the shift shoes properly align.
(some guys have had a "stuck" shifter and have had to remove their lower first, then the upper, to be able to fix the problem.)