Did I ruin my motor??? (cracked exhaust)

[fbnewbie]

1978 Mercury 20 hp. <br /><br />Same ole story. LU would not come free. I have the manual and checked all bolts. Read all topics here and took each step<br /><br />In the process I did the following<br /><br />1) cracked off small front piece of fin<br />2) cracked the housing flange on the exhaust housing(??) that sits atop the LU. <br /><br />Can it be saved

 

[hondon]

Re: Did I ruin my motor??? (cracked exhaust)

Did you ever get the gearcase off?

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

No, I stopped before I did any more damage

 

[1968_Red_fish_IMP]

Re: Did I ruin my motor??? (cracked exhaust)

Sounds like you missed a bolt or two. doublecheck that. how many nuts and how many bolts hae you removed? good luck

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

I have removed the two nuts above the propeller shaft and the one nut at the front of the motor directly above the lower unit. Also the plate above the propeller shaft that is held on with the allen wrench nut. I can't find anything else to loosen.<br /><br />Now I am afraid to do anything else because I think I ruined it already by doing what I stated above in my first post<br /><br />Any and all advise is HUGELlY appreciated.

 

[sangerwaker]

Re: Did I ruin my motor??? (cracked exhaust)

Check inside the area where the plate above the prop shaft was. Inside that cavity, there is usually another bolt.

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

I got the two under the plate and the third from the hex nut that leaves only the one at the top back of the exhaust housing. I got that too.<br /><br />I read and reread the manual so I am pretty confident that it is just frozen on. But, now I don't want to do any more damage and am wondering if it is salvagable at this point?

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

Any and all opinions on the crack situation are greatly appreciated.

 

[rodbolt]

Re: Did I ruin my motor??? (cracked exhaust)

fbnewbie<br /> what part of the world are you in? any place close to NC ?

 

[Greg New Zealand]

Re: Did I ruin my motor??? (cracked exhaust)

Is there any gap at all between the upper & lower units? Usually if there is no gap or only a very slight gap at the front or rear, it indicates that there is still a bolt in place.

 

[Docdoc]

Re: Did I ruin my motor??? (cracked exhaust)

I'm no expert here, but if you have all the bolts out. then you are looking at one (or more ) of several possibilities.<br />1. You did not disconnect the shift linkage. This will hold the lower unit in place.<br />2. Corrosion has sealed the lower unit to the motor leg. Some heavy soaking with penetrating oil may help.<br />3. The drive shaft is stuck in the power head. some fancy manuvering may be needed to solve this one. <br /><br />The good news is you have not completely ruined the motor. If the fin you cracked a piece off of is the cavitation plate (right above the prop, then it will still function as is.<br /><br />The motor leg (exhaust housing) is a little different. If you get the lower unit off, you can also remove the leg it just bolts onto the bottom of the power head and is held on by the bottom motor mount. You can either take it off and see if you can find a welder that works with aluminum. If he is pretty skillful he can weld the crack up. However, this may distort the flang a little and require it to be dressed up. It will also affect the overall strength around the weld and weaken it. If nothing else, you may be able to find a parts motor to rob a leg off of. e-bay is always a good place to look.<br /><br />Just remember to take it slow and easy, use lots of penetrating oil and don't fall apart if you twist off a bolt or two. Even the pros do it

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

I am in Oregon<br /><br />I can get about 1/4 inch on the back but the front doesn't budge.<br /><br />The manual says NOTHING about the shift linkage. Where do I remove that from???<br /><br />How do I best get penetrating oil into it?<br /><br />Thanks so much

 

[Docdoc]

Re: Did I ruin my motor??? (cracked exhaust)

I'm not familiar with merc., but shift likage runs either part way or all the way up the inside of the exhaust leg. It connects to your shift lever on the side of the motor, or inside the cowling if your motor is remote shifted. Either way, there should be an adjusting nut that the two halves of the shifting rod screws into. It will be a super wide nut (maybe 1-1.5 inches wide). It should be exposed where you can see it. If you have one, completely unscrew it from the lower half of the shift rod.<br /><br />If you don't have an adjusting nut, look for an access plate on the side of the lower leg. It will be held in place with a couple of screws. remove the plate and look for a bolt or screw that clamps the lower half of the shift link in place. Back off on the screw/bolt until the shift rod slides free.<br /><br />VERY IMPORTANT: Be sure you support the lower unit wild disconnecting the linkage, or it will fall out on the ground. Or with my type of luck, the concrete and crack the case open.<br /><br />Pentrating oil can be WD-40, or Liquid Wrench spray.<br />Good luck

 

[andrewkafp]

Re: Did I ruin my motor??? (cracked exhaust)

When you are sure you have got all the bolts. I would advise that you remove the plastic water inlet covers revealing a rectangular hole.Put a solid steel bar through it a whack the bar instead of the L/U surface. Also use wooden wedges. The shiftshaft on the 78 should just fit into a spline.A 78 also has a stainless steel drive shaft.<br />A digital pic of the motor and damage would help with the repair technique.

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

Where do I find the "plastic water inlet covers"??

 

[Docdoc]

Re: Did I ruin my motor??? (cracked exhaust)

Small plastic screens where water enters the lower unit to go to the water pump. On each side between the prop and cavitation plate. Be careful removing them or you will break them.

 

[andrewkafp]

Re: Did I ruin my motor??? (cracked exhaust)

This is a 1978-20HP Merc<br />The water pickup is in the middle of the Lower unit above the prop as shown.<br />

 

[Docdoc]

Re: Did I ruin my motor??? (cracked exhaust)

I would try using a couple of wooden wedges between the exhaust housing and lower unit. Drive em in slowly

 

[fbnewbie]

Re: Did I ruin my motor??? (cracked exhaust)

Thanks so much everyone. My next step is the wooden wedges and to hunt for a parts motor to replace the damage that I did.<br /><br />I will let you know how things turn out.

 

[Clams Canino]

Re: Did I ruin my motor??? (cracked exhaust)

And re-verify you got **all** the bolts. Some go up, some go down, some are nuts on studs.<br /><br />-W