MC-1 Drive locked up ?

[McL0V3N1121]

I recently bought my first boat and it needs some work, I have completely re wired everything and am finally able to get it to turn over. the motor will start to spin but stop almost instantly, and it kind of twists. like something is holding it back from doing its job. it seems like to me that the lower unit may be locked up, the guy told me when I bought it that it MAY need some lower unit work. my question is if the lower unit is locked up, would it prevent the engine from full rotations or no ? it is a 1966 sterncraft mercruiser sterndrive 120 4 cylinder.

 

[flipbro]

Pull the drive and crank it over. If it cranks freely then you know it's the drive. The split the drive and turn shafts by hand to determine if its top or bottom.

 

[Eric 3.7LX Alpha 1]

Yes a locked up drive will lock up an engine. I hope the price of the boat took that into account.

You can also run the engine with the drive removed. Stick a garden hose in the water inlet in the bellhousing and turn it on. Just make sure it doesn't come out.

 

[Bt Doctur]

being that old its most likely a 8 spline shaft and will not interchange with newer lower units. complete drive replacement might be the best bet.

 

[Fishermark]

You might want to pull the spark plugs and see if any water comes out as well. Just sayin....

 

[McL0V3N1121]

Thanks for the advice. I am about to start removing the drive now.

 

[McL0V3N1121]

Yes, I only paid $400 for the boat and trailer.

 

[McL0V3N1121]

I followed the steps and have everything ready to separate the drive from the gear housing. The manual says to separate the 2 at this point. Does anyone know a decent way to separate the 2 ? They been together so long now that they are really stuck together. I've sprayed WD40 on it and scraped the line where the insert into eachother but can't get them to separate. Also if I do end up doing a complete drive replacement, where is a good place to get the new parts/drive. Again, thanks for all the advice guys.

 

[McL0V3N1121]

I got the drive shaft housing and the gear housing off and the motor turns over strong. It is the drive shaft housing ( upper ) that is locked up not the bottom. I will will need to work on this now. I pulled the spark plugs out, looks good, no water. It is an 17 spline shaft that goes into the motor.

 

[Eric 3.7LX Alpha 1]

pull the top cover and have a look at the gears in the upper.

 

[McL0V3N1121]

That's my next step.

 

[Bt Doctur]

left you a number

 

[McL0V3N1121]

How difficult will it be for me to remove all the internal parts in the drive shaft housing ( upper ) inspect them, clean everything, replace the part/parts that need replaced, put back together and also will I need any special tools ? Would it be better to rebuild mine or try to find a good used one ?

 

[Bondo]

and also will I need any special tools ?

Ayuh,..... The specialty tools alone is only alittle more expensive that a brand new replacement drive by SEI,....

Any parts will add up fast enough too,.....

 

[McL0V3N1121]

Looks like I need to find a good used one. Where would be a good place to start looking. For both used and new.

 

[Bondo]

Ayuh,..... New,..?? Right here at iboats,.....

Used,..?? Donno where you are,.... craigslist,... local marinas,...

 

[wahlejim]

I have had an SEI outdrive on my boat and haven't run into any issues. They also have a decent warranty and are fairly priced. When you get a used one, you have no idea what you are getting yourself into. In my opinion, it is worth the money.