Rebuild, Rings, or Run it as is?? 25 hp Merc 2cyl 2stroke (pic heavy)

xjma

Petty Officer 3rd Class
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Mar 12, 2012
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Re: Rebuild, Rings, or Run it as is?? 25 hp Merc 2cyl 2stroke (pic heavy)

in the FAQ 'compression test by JB' there is mention that the motor should be warm (exhaust cover and water jacket are off, so that's not possible) and that rope pull motors give lower compression numbers. I could hook this thing up to a battery and turn it, would that be worth it?? Or could that be not a good idea since not hooked up to fuel, hence, not so much lubricated. Should I pour some oil down the cylinders? I tried to PM the poster of the FAQ but their pm box was full. Mechanic suggested calling the local merc place.....which I may do. I really am not convinced that the motor isn't good, guess I need to stop posting Qs and just put it together and try it out.
 

sutor623

Rear Admiral
Joined
May 23, 2011
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4,089
Re: Rebuild, Rings, or Run it as is?? 25 hp Merc 2cyl 2stroke (pic heavy)

in the FAQ 'compression test by JB' there is mention that the motor should be warm (exhaust cover and water jacket are off, so that's not possible) and that rope pull motors give lower compression numbers. I could hook this thing up to a battery and turn it, would that be worth it?? Or could that be not a good idea since not hooked up to fuel, hence, not so much lubricated. Should I pour some oil down the cylinders? I tried to PM the poster of the FAQ but their pm box was full. Mechanic suggested calling the local merc place.....which I may do. I really am not convinced that the motor isn't good, guess I need to stop posting Qs and just put it together and try it out.

Dude your numbers will read fine with a cold motor. Try it without putting oil in first, then with oil. If there is a huge difference then you may have some severe scoring. It is ideal to check with motor warm, but not entirely necessary.
 

sutor623

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May 23, 2011
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4,089
Re: Rebuild, Rings, or Run it as is?? 25 hp Merc 2cyl 2stroke (pic heavy)

Oh and it will be fine to just give it 4 or 5 pulls with the rope. Just be consistent between cylinders. No need to use an electric starter.
 
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