72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Eric the Red

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Watch your temp! 140-150 probably. If it gets hot (180), even for a minute or two shut her down. Did you service the water pump? If not, that should definately be you next project. Only a few $ for a new impeller. If it fails, you may need a whole new engine. Likely you will need a new water pump, mine was $50 just a few weeks ago...
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

As it is it pumps a crapload of water. When removing the lower unit will I have to replace the water pump for sure or just the impeller? also, the water temp guage doesn't work I think. So I'll get on that before I take it out
 

series60

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

As it is it pumps a crapload of water. When removing the lower unit will I have to replace the water pump for sure or just the impeller? also, the water temp guage doesn't work I think. So I'll get on that before I take it out

A lot will depend on what you find when you drop the lower unit. The water pump housing which the impeller runs in may be scored and warm. Being unknown to the condition of the pump, just plan on replacing the housing and the impeller. If it looks good when you get into it you can probably get away with just replacing the impeller. It's not that much more $$ for the complete housing and impeller.

There a few simple tricks installing the pump so be sure the read the articles pertaining to water pump installation in the Adult section at the top of this forum.
 

Fishermark

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Alright, well I lubed everything up and gave it a kick and it went in.

I'm glad you got it on, and you may be fine. BUT... you may still be in trouble and could wind up pulling the engine and replacing the coupler. As mentioned by the others, you really should check your engine alignment. If it is out of alignment it puts added stress on the coupler and it may be short lived. The only way to know for sure is to check. Loosen up the wallet and buy an inexpensive alignment tool and be done with it. ;)
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Alright so I agree with you about making sure the engine is aligned properly. I am going to rent the tool and do it myself. Now I've done a little reading on it and watched some videos but I am still somewhat confused. I understand that the tool should go in all the way nice and smoothly, but is that it? Does it have anything to do with engine mounts? Or the way the splines line up? I'm just confused as to how the couPler functions and how to properly align the engine. Other than it going in smoothly all the way. Is there a certain pattern I'm looking for? Or is it just making sure it goes in smoothly with grease marks all around and I'm done? Cause man I will be pissed if I have to pull the motor. I don't have the experience to do that!!! Lol
 

series60

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Alright so I agree with you about making sure the engine is aligned properly. I am going to rent the tool and do it myself. Now I've done a little reading on it and watched some videos but I am still somewhat confused. I understand that the tool should go in all the way nice and smoothly, but is that it?

Pretty much not with standing the grease tracings are even all the way around the tool.

Does it have anything to do with engine mounts? Or the way the splines line up?

It has everything to do with the engine mounts. Those are what must be adjusted up or down to get the proper alignment. Engaging the tool into the coupler makes the grease tracings from the splines which are what you are looking for. Tracing must be even all the way around the tool.

I'm just confused as to how the couPler functions and how to properly align the engine. Other than it going in smoothly all the way. Is there a certain pattern I'm looking for? Or is it just making sure it goes in smoothly with grease marks all around and I'm done? Cause man I will be pissed if I have to pull the motor. I don't have the experience to do that!!! Lol

Look at the video from FriscoJarretts
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Okay guys, I have a mercruiser alignment tool on the way from Ebay. while I have the drive off I am going to seperate the lower unit and check out the impeller and housing. I read up on it in my manual, but it is just basic.... any suggestions for removing it and putting it back on? I once replaced an impeller on an outboard motor and had a hell of a time getting the water inlet and outlet pipes back on :( but is there any cool tricks or ideas I could use? I am going to lay the drive on its side and put it back together that way. also. I noticed that when my engine is running it shakes a little bit.. I'd say about a half inch. bad engine mounts? = possibly ruining the coupler?? and is there a water pump kit that also has the lower unit gasket and everything I will need for the job? gaskets, O-rings yada yada?? thanks again guys~!
 

Eric the Red

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

IMAG0207.jpg
Here are some photos of the outdrive removed, after I cleaned it up some.

IMAG0230.jpg
You will need a new gasket for the bell housing, an O-ring for the water passageway, and a rubber sealing ring inside the bell housing.

IMAG0208.jpg
I worked on mine on its side the first time, but I've since built a stand out of 2x4's. It makes the install much easier.

IMAG0239.jpg
The water Pump kit came in the small white box. Housing, Impeller, water tube guide, O-rings, face plate, gaskets...

You will need 2 quarts of Mercury gear oil, and a pump to refill the outdrive (mine was $12).

All together, it was about $75 for everything I needed.

Take a good long look at all of the bellows while you're into it this far, as well as the splines, and inspect the shift cable for rust and wear.

GREASE EVERYTHING you can get a grease gun onto, especially the U-joints. Lube splines before reassembling.

Good luck!
 

broush69

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Had the same issue with my mercruiser 165 3.7L 4 cylinder. Everytime i put the boat in reverse it would die. So i took out the shift cables and pulled on the reverse until the engine didnt die and set the nut which its easily adjusted to the spot where the engine didnt die. Its not been running perfect when i throw it in reverse.
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

I've already replaced the cable, I just need help with some details on alignment and information about the motor mounts. Is there a gasket for the lower unit? if so, where can I buy one? and could I get a link for a water pump kit?
 

Fishermark

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

No gasket for the lower unit. There is a "quad ring" that seals the oil passage. It looks like a square O ring (which sounds contradictory doesn't it? ;) ), but that is the only seal between the upper and lower.
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Thank you so much lol! I have been looking everywhere. where could I buy it?
 

series60

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Thank you so much lol! I have been looking everywhere. where could I buy it?

Quad rings are very small o-rings and your best bet is to go to a Mercruiser shop. They are usually sold with other gaskets but if you just need one quad ring then a shop might be your best bet
 

ktbarrentine

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Quad rings are very small o-rings and your best bet is to go to a Mercruiser shop. They are usually sold with other gaskets but if you just need one quad ring then a shop might be your best bet

+1 on that... You could spend 2.29 online (part number 26-455771, typically), if you buy it outside of a water pump kit, then get soaked for ten bucks shipping (or if you search hard enough, you might find a better deal).... My prob is that it typically takes me ten bucks worth of gas to go to (and from) my "local" marine shop! (oh, and that 2.29 typically gets you three of them).
 

2101394sam

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Re: 72 Mercruiser dies when I try to put it into gear. and it won't engage help!

Thank you guys! I just went ahead and ordered an entire waterpump kit with the housing and all. ALSO! I pulled the drive off and found out that the black sealing ring got caught on something when I put the drive in and it got torn in half. Also, I got the alignment tool and aligned the boat, I have it aligned perfectly except for the third time I rotated the engine 90* there is still some slight pressure from the right side and not up and down. I Don't know what else I could do so I just put the drive back in untill I get the waterpump kit.
 
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