1971 mercruiser 165 will not spin prop when engaged.

[ziggy]

Re: 1971 mercruiser 165 will not spin prop when engaged.

is there a way to tell if this is a gen 1 or gen 2?

sure, by serial number.
like said before though, ya don't have a alpha1 or a alpha1 gen. 2. ya have a one drive probably, from yer description.....

http://www.mercstuff.com/howdoi.htm

follow the link for how do i know which outdrive i have...

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

anything up to and including an alpha 1 gen 1 will bolt up to the housing. You probably have a #1 drive with an eyelet in the top cap.
however.... it doesn't do ya any good to buy a drive unless its pressure tested first.
And it NEEDS to be the same gear ratio... changing the prop won't fix it. I have a feeling that there is nothing wrong with your drive except that it leaks. If you seal it up it should be ok. I think your shifting woes are coming from someplace else. Is this a saltwater boat?

I completly understand that i dont have an alpha 1 or 2 drive.

However from this post im understanding i can bolt up and use a alpha 1 gen 1 as a replacement?

If this is incorrect plz tell me so!

I know i currently have a pre alpha drive.

thanks all for your continued help!!!

 

[Haut Medoc]

Re: 1971 mercruiser 165 will not spin prop when engaged.

I completly understand that i dont have an alpha 1 or 2 drive.

However from this post im understanding i can bolt up and use a alpha 1 gen 1 as a replacement?

If this is incorrect plz tell me so!

I know i currently have a pre alpha drive.

thanks all for your continued help!!!

Yes, an Alpha One, gen 1 will bolt right on.....
You need a 1.65:1 ratio....
I still don't know why everyone needs to make a big deal about the different distinctions Model 1/R/MR/Alpha one, they are all basically the same unit, with slightly different innards, the only time the difference matters is when you start mixing & matching uppers & lowers.....
The $1195 unit you see advertised at the top of the page will bolt right on to your rig......

 

[Haut Medoc]

Re: 1971 mercruiser 165 will not spin prop when engaged.

With regard to the Craigslist drive, call & ask him what year & what size the engine is.....
If it is before '91 & the engine is a GM 4.3 liter V6, you are in business....​

 

[HT32BSX115]

Re: 1971 mercruiser 165 will not spin prop when engaged.

Well, I read thru this post and I don't think I saw it so I'll make the suggestion.

You might consider getting one of these.

Regards,

Rick

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

With regard to the Craigslist drive, call & ask him what year & what size the engine is.....
If it is before '91 & the engine is a GM 4.3 liter V6, you are in business....​

This answer if very helpfull! simple to understand in land lubbers english! thanks!

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

ok the outdrive is a 86 model and is from a 266 cubic inch motor. does that sound like a 4.3l?

 

[Haut Medoc]

Re: 1971 mercruiser 165 will not spin prop when engaged.

ok the outdrive is a 86 model and is from a 266 cubic inch motor. does that sound like a 4.3l?

262 CI V6, yes it should work...

 

[JustJason]

Re: 1971 mercruiser 165 will not spin prop when engaged.

i bet he's got a bad hub

 

[Bt Doctur]

Re: 1971 mercruiser 165 will not spin prop when engaged.

Being a 71 you may have a "coarse spline shaft" lower unit.If so a late model lower unit with a "fine spline" will not fit.However a complete unit will bolt up to the transom. Make sure the gear ratio is correct and the input shaft is the correct length.

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

update!

Well i ended up getting the complete outdrive assembly from a 86 4.3l alpha 1 gen 1 unit. very good shape too! it was 300 bucks. when i got there the guy cut the whole motor and outdrive assembly out of his boat and had it hanging from a tree. lol He was wiping the sweat off his face and swore he would never to that again! he was so disgusted he said i could have the whole motor and sterndrive assembly for only 400 bucks! still has the carb and accessories and electronic ignition and powersteering and power trim cylinders and everything! i feel i hit a really good deal here! He said the motor locked up do to a cracked head or manifold or something, however i think i should be able to get my money back from parting it out on here and craigslist.

Anyways back to topic, im going to begin the swap tonight. wish me luck!

 

[FreeBeeTony]

Re: 1971 mercruiser 165 will not spin prop when engaged.

be careful of the length of the input shaft.........the inline engines used a longer input shaft..........I would compare it to your original.

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

haha wish i had that advice before i tried to install it! lol However it ended up being flip floped. my inline had a shorter input shaft and the v6 and a 1 inch longer input shaft. anyways i got to take out my frustration on those pesky ujoints.

anyways she's done! looks like a successfull instalation! thanks all

 

[FreeBeeTony]

Re: 1971 mercruiser 165 will not spin prop when engaged.

knew they were different........just had it backwards..............

did you replace the bellows also?

 

[bigguy6f4]

Re: 1971 mercruiser 165 will not spin prop when engaged.

yes altho i could not find anything wrong with the one i had. do you think its possible the lowerunit was leaking somewhere, filling with water, the water overheating and then vaporizing and getting past the seal on the upper unit and just steaming into the bellow area? i say this cuz there was no rust or anything in the bellow area,, just clearish water. when i took apart the alpha 1 it had water in the bellows area too, and it was all rusted up looking. and the ujoints looked rusted too.

 

[ziggy]

Re: 1971 mercruiser 165 will not spin prop when engaged.

when i took apart the alpha 1 it had water in the bellows area too, and it was all rusted up looking. and the ujoints looked rusted too.

if yer refereing to yer replacement drive. i'd think ya should R&R the ujoints + go inspect the front seal of the drive. especially the drive gear yoke as the seal surface will rust if water is present..... as for the water steaming out. i've no idea. i do understand that the ft. seal on the drive seals oil in, but does not seal the other direction. so if water is present, it can leak into the drive from that front seal...... heres what a little water will do for yer yoke.....

i replaced this part in mine..... didn't like the rust groove. i had no water present in my bellows when i removed them. only the signs that there'd been water there......

 

[ramair351]

Re: 1971 mercruiser 165 will not spin prop when engaged.

if yer refereing to yer replacement drive. i'd think ya should R&R the ujoints + go inspect the front seal of the drive. especially the drive gear yoke as the seal surface will rust if water is present..... as for the water steaming out. i've no idea. i do understand that the ft. seal on the drive seals oil in, but does not seal the other direction. so if water is present, it can leak into the drive from that front seal...... heres what a little water will do for yer yoke.....

i replaced this part in mine..... didn't like the rust groove. i had no water present in my bellows when i removed them. only the signs that there'd been water there......

hi guys, i have been following this thread intently! Is there a way to take the nut off this yoke without separating the upper and lower units? its right next to that vertical shaft! i need to replace my upper seal also. 1972 sea ray pre-alpha outdrive