Suzuki Lower Unit Surgery

jshell55

Recruit
Joined
May 24, 2003
Messages
4
Got about a 10-year old suzuki 50hp. Ran fine, except would only move forward or reverse at about 1 mph, even at high RPM's. Motor turning fast, prop turning slow, even "in gear".<br /><br />Deduced from this that the lower unit was/is bad, and the prop :confused: slipping against the force of the water.<br /><br />Managed to get the lower unit off and have been trying to get in to the lower gearbox, to inspect for worn parts, etc. but cannot figure out how to do it. According to earlier posts, might be press-on bearings, etc. that require real tools/know how to do it. Already used brute force to get the prop shaft seals out, but now what?<br /><br />Are these lower units meant to come apart, or do you just replace them per many other posts? Ideas?
 

Valv

Petty Officer 1st Class
Joined
Jun 12, 2001
Messages
391
Re: Suzuki Lower Unit Surgery

Are you sure lower unit is bad ?<br />Seems to me you have a spun hub on your prop.<br /><br />I would put it back together, and try with another prop, or mark with a Sharpie one spot on outside prop hub and matching one inside, where it slips on propshaft, if your hub is spun, they won't match anymore when you re-check them.<br /><br />A lower unit with mashed gear teeth is not something you won't notice, it will clunk and grind like nothing else, definitely noisy.
 

jshell55

Recruit
Joined
May 24, 2003
Messages
4
Re: Suzuki Lower Unit Surgery

You guys are good. After inspection of this I agree the prop is stripped. If I can get this guy back together I will be in business. <br /><br />How many decades ago did they do away with shear pins?
 

beeekeeper

Recruit
Joined
Feb 10, 2008
Messages
2
Re: Suzuki Lower Unit Surgery

I have a similar problem with my DT25; drives ok at low revs but no power at higher revs.

My prop appears to have a brass splined hub which (obviously) fits over the splined prop shaft.

So is the brass splined hub inside the prop meant to do the same job that shear pins used to do in older and/or smaller motors?

If so then once a hub becomes spun can it typically be repaired/reset or is it a throwaway item to be replaced?

Thanks.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: Suzuki Lower Unit Surgery

shear pins are for older but more especially lower HP motors... You guys may want to think about replacing your prop's with Mercurys Quicksilver line of props. Their flo torque hubs behave much more like shear pins do and they are more reliable hubs then bronze on rubber.
 

beeekeeper

Recruit
Joined
Feb 10, 2008
Messages
2
Re: Suzuki Lower Unit Surgery

ok great; Can you refer me to a website to determine which prop model can I retrofit to my 1981 DT25P motor?
 
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