'93 25 HP Merc 2-Cyl, Electric Start

prginocx

Seaman Apprentice
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Mar 1, 2005
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39
It has tiller control handle. <br />Looking to buy this boat / engine combo. What is the expected compression if the engine is barely used ? <br /><br />Also I have looked through the manual and I don't see what the alternator is rated for....Does it even charge the battery when running ? It also has rope start.<br /><br />Are there any modifications I could make to increase the horsepower ? Is this power head made by Mercury or ?
 

andy6374

Lieutenant Commander
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Aug 4, 2005
Messages
1,617
Re: '93 25 HP Merc 2-Cyl, Electric Start

Look for even compression between each cylinder, not a particular number.<br /><br />I think merc manufactures all its blocks except it's 4stroke line which yamaha makes.<br /><br />As for performance, make sure the engine is at the proper height and that it is propped correctly.
 

prginocx

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Mar 1, 2005
Messages
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Re: '93 25 HP Merc 2-Cyl, Electric Start

I do appreciate the information.<br />Please tell me if I'm even in the right range. I figure a really good condition used motor ought to be around 90 to 140 psi....<br />Right ?<br /><br />And how about if top / bottom cylinder are within 10 to 15psi of each other ? Am I on the right track ?<br /><br />Anyone have an idea on the alternator rating for this guy ?
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: '93 25 HP Merc 2-Cyl, Electric Start

What you're really looking for is no more than 10% difference in comp. between cylinders. <br /><br />Remember, different gauges will probably give you different reading and hence the actual number is less important.<br /><br />Don't know the alternator rating, probably in the 4-9 amp range.
 
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