help motor problems

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bowes001

New member

• Apr 20, 2015

• #1

I have a 84-85 merc 18xd. The number is 06617745. If anyone knows how to remove the cranckshaft that would help. Also I just flooded the pistons with marvel because they are froze up and a lot of it came out of the prop???? Please help me!!!!! I don't want to get rid of it

 

faztbullet

Silver Medal Contributor

• Apr 20, 2015

• #2

Pull the powerhead and split the crankcase....

 

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bowes001

New member

• Apr 21, 2015

• #3

I did that. I still can't pull the crankshaft

 

fastjeff

Gold Medal Contributor

• Apr 21, 2015

• #4

Carefully pry her up with two screw drivers.

Jeff

 

faztbullet

Silver Medal Contributor

• Apr 21, 2015

• #5

Be very careful doing this as that a chrome bore block and if motor overheated and seized its done....

 

fastjeff

Gold Medal Contributor

• Apr 21, 2015

• #6

Right. If the crank still won't come out, under the rods (and mark the ends--they do not interchange).

Jeff

 

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bowes001

New member

• Apr 21, 2015

• #7

So use screw drivers to pry up under the rods? And why did the marvel run out where the prop is???

 

R

racerone

Gold Medal Contributor

• Apr 21, 2015

• #8

If exhaust ports are open then oil runs right through the motor !!!!

 

B

bowes001

New member

• Apr 21, 2015

• #9

That makes sense I bolted it a few in but I didn't pull of of them back in

 

B

bowes001

New member

• Apr 25, 2015

• #10

Can anyone find me what size the piston rings are please and why does one piston go in and out smoothly but the other gets stuck or won't even go in??

 

faztbullet

Silver Medal Contributor

• Apr 25, 2015

• #11

The std bore size is 2.562 for your motor. The sticking piston could be due to a warped cylinder as this is a aluminum hole that is chrome plated and if it gets hot it will warp so have it miked... Also these blocks are bad about exhaust bridge warping and dragging against piston. The bad news is there is no aftermarket piston or rings for that engine unless you find some NOS someone has, if not they will have to come thru a Merc dealer as it uses a special ring for the chrome bore.If any of the chrome plating is or peeled/deep scuffed or flaking the block is junk. I used to bore and sleeve them (have boring bar) but it has become to expensive to do as you can buy a block kit cheaper....

 

Last edited: Apr 25, 2015

faztbullet

Silver Medal Contributor

• Apr 25, 2015

• #12

These motors have a S/S shaft and they wont pit like a carbon steel one.....