165 mercruiser upgrade? On houseboat

Bobpalmer

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I’m restoring a 80s model stardust cruiser houseboat with a 80 model 165 mercruiser that runs good but doesn’t want to idle sometimes usually when I’m trying to dock it lol is this common with this engine or do I need a new carb also would like more power how hard is it to increase horsepower on these
 

nola mike

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There are 2 165 hp mercs, a 6 and 4 cyl. You probably have the 4 cyl, but who knows. Either way, increasing power in a boat generally involves a new engine, or a rebuild if an old tired one. And what does it want to do instead of idling?
 

Scott Danforth

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if its dying as you go in and out of gear, check the shift cable adjustement

as Mike indicated, there were two 165 horse motors. the 250 cubic inch 6-cylinder and the 470 family 4-banger
 

Bobpalmer

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It’s a straight 6 Chevy I’m thinking I may have to let it completely up to temp before adjusting carb it’s idling a little high and hard to shift also
also is there aftermarket mods that give you more power?
thoughts on converting to electronic ignition?
 

nola mike

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A houseboat with a 165hp is never going to be a hot rod. Scott Danforth is going to go on and on about how great points are, but they're a PITA. you won't get more power with electronic, just less maintenance. But you won't get stranded at sea with points either. Need more info on hard to shift. Also more info on your boat. Sounds like you need to start with checking your points and timing, both affect your idle.
 

Scott Danforth

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If its hard to shift and its dying at idle, you need a new lower shift cable, and it needs to be adjusted.

Nothing wrong with points, or electronic dizzy. Just not worth the cost to change by itself.

A houseboat is a displacement hull. It wont go any faster with even double the power. You will get the same top speed with a 50hp outboard as you would a 300hp v8. You are limited by hull speed

To get more power from your inlinner.....you need more displacement or a blower. Neither of which will push your houseboat faster than hull speed
 

Bondo

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It’s a straight 6 Chevy

Ayuh,...... Welcome Aboard,...... For increasin' the power, ya got 2 choices,.....

The Chevy 292 I-6 could be bolted in the same spot, but they're extremely hard to find,......

Not quite as easy of a swap, would be goin' to V-8 power, which is more work, but much easier to find,.....
 

Bobpalmer

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Well I worked on carb finally figured out that it wouldn’t return all the way to idle because linkage was loose adjusted linkage and repositioned spring to bring back to idle
will idle and shift now with ease only problem is one of the air fuel mixture screws has to be all the way in other one one is about 2 turns out from all the way in still doesn’t idle really smooth
will a carb rebuild fix this or do I need a new carb?
 
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