Will a mercruiser 260 lower unit work on a mercruiser 165?

rbunk13

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May 2, 2010
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I have a '81 renken I just bought that has a mercruiser 165. Trouble is that the guy said he hit something and the shop told him the gears are bad. I have a spare mercruiser 260 outdrive and was wondering if it would fit? Thanks for any help.
 

Bondo

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

Ayuh,... It'll probably bolt on, but the gear ratio is Waaay too tall...
The motor will lug, 'n kill itself from detonation...
 

rbunk13

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

I was afraid of that. Prob better to find a used outdrive. Repair is prob expensive.
 

ziggy

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

yer saying it two different ways.
Will a mercruiser 260 lower unit work on a mercruiser 165?
I have a spare mercruiser 260 outdrive
i could be mistakin. but the i'm under the impression the gear ratio change occures in the upper.

so if yer wanting to R&R the whole drive. what Bond-o says would be true. the gear ratio will wrong.

however if ya just R&R the lowers. i think they are the same and will interchange.

the pros will correct me if i'm wrong please..
 

stonyloam

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

Just to clarify: Are you asking about just the "lower unit" or the whole outdrive? There are two parts to the outdrive, the driveshaft housing (where gear ratios are determined "upper") and the gearcase where the prop shaft is ("lower"). If the lower is bad you might be able to do the swap.
 

rbunk13

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

Not sure I guess. He said the shop told him the gears were destroyed but he took it out and ran it after the big hit and he said it would run just not get up on plane. I noticed there is a 1/4" gap or more where the prop mounts also. which is making the prop hit the little steering fin above it. Prop bearings maybe?
 

Lyle29464

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

You need to take it to a merc shop or have a service call from a good mobile repair co. Don't tell them you think it's the prop bearring.
 

rbunk13

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Re: Will a mercruiser 260 lower unit work on a mercruiser 165?

Took the prop off and found out the housing is cracked. I then took off the outdrive and noticed water in the u-joint bellows. ugh
 
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