mercruiser, 3.0 liter 140 horse. no power in gear

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bobby1964

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Jul 18, 2004
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hi, i got a sunbird corsair, '86. took it out and the angle drive gears (sterndrive?) lost all teeth, replaced with one off a V8, (does this matter?) also replaced some burnt out wires, (even though i dont know what they do) to the switch on the rocker cover. problem i have is.. runs fine in netral, or on the drive with muffler, but put her into gear in the water and she only does half power. what have i done wrong, also, getting back into neutral is a *****, (checked out the other sites, will attempt the adjustments this weekend)<br />this is my first boat, and as you can probably tell, i aint got a clue. all tips greatly appreciated.
 
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goodtimeguy

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Jul 14, 2004
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Re: mercruiser, 3.0 liter 140 horse. no power in gear

you have to put in gears from the same engine size or else your ratio will be wrong, and your final drive will not be correct. sound like this is your problem.
 
Bondo

Bondo

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Re: mercruiser, 3.0 liter 140 horse. no power in gear

Ayah,<br />The Ratio is Way to Tall.......<br />You need 1.98/1s......<br />You'll Never find a Prop Small Enough to make up the Difference.......<br /><br />If you Properly Fix the Burnt Up Wires,<br />It'll Shift Much Better.........<br /><br />BTW,<br />Welcome to the iboats forums.....<br />Do a Search on Outdrive Ratios...<br />And Interupter Switches.............
 
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bobby1964

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Re: mercruiser, 3.0 liter 140 horse. no power in gear

didn't realise was a ratio difference. thought it was just a one to one transfer drive. looks like i'll have to find another one eh? thanks lads. i'll let you know how i get on.
 
Bondo

Bondo

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Re: mercruiser, 3.0 liter 140 horse. no power in gear

The Ratio is changed, by changing the Upper Gear Set..............<br />All the Lower Unit Gear Sets are 1.65/1..........<br />The Combined, or Over-All Ratio ends up at;<br />1.32/1... Big Block V-8... Quite Rare.....<br />1.50/1... V-8 power<br />1.65/1... I-6 power<br />1.84/1... V-6,+ the Lovely 470.......<br />1.98/1... I-4 power......................... ;) <br /><br />You Could swap out your Gears,<br />But,<br />It'll be Cheaper to scrounge up Another outdrive............<br />Ebay...??
 
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bobby1964

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Jul 18, 2004
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Re: mercruiser, 3.0 liter 140 horse. no power in gear

got someone checking e-bay out for me now. they got gear sets too, see if they got mine eh. got to say these forums are great.
 
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bobby1964

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Jul 18, 2004
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Re: mercruiser, 3.0 liter 140 horse. no power in gear

hi, sorry. nother question. would a 1;84/1 also do the job? can get one of those, or someone told me that an 8;88(?) would also do, and he has one of those. (i think he said 8;88) ta again. bobby
 
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goodtimeguy

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Jul 14, 2004
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Re: mercruiser, 3.0 liter 140 horse. no power in gear

call a dealer that sells the kind of out drive that you have(omc,merc,etc)give them the serial number off your leg and find out the gear ratio. then you will know what to look for.
 
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cobra 3.0

Lieutenant Commander
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Jul 31, 2003
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Re: mercruiser, 3.0 liter 140 horse. no power in gear

Follow Bondo's advise and get the 1.98/1.
 
TwoBallScrewBall

TwoBallScrewBall

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Sep 14, 2003
Messages
1,695
Re: mercruiser, 3.0 liter 140 horse. no power in gear

If all else fails or if a 1.84:1 drive falls out of the sky and lands in your gimble housing, it will work OK with a pitched-down prop. Might never be optimal but it's only a 5% difference in drive ratio which a change of 2" in prop pitch should theoretically override. <br /><br />As you know, in theory there is no difference between theory and practice, but in practice there is. ;)
 
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