1985 Mercury 18xd conversion to 25hp?

nelsonag

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Oct 5, 2020
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5
So I just purchased an old 16 foot tin boat and the guy, he also gave me his 85 Mercury 18xd. I was watching some youtube videos of guys saying it is the same engine block as the 20 and the 25xd (but the model was a few years earlier and not the xd version). I called mercury and the guy on the phone was like "theoretically, technically, check the part numbers" Just curious, does anyone know can the 18xd be easily converted to get more juice from it?
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,931
Throw a 25 carb on it and go...bingo ,bango presto,changeo its a 25 under a 18 cowl..
 

nelsonag

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Oct 5, 2020
Messages
5
You also need the exhaust tuner.
Thanks for the replies gents. If I find a 25 carb, will the power gain be negated by the restricted exhaust tuner? or is that negligible? Also, if anyone has any ideas on how to turn these in to remote steering from tiller im all ears, funky throttle system
 

flyingscott

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Apr 8, 2014
Messages
8,154
You need the linkages for the remote throttle and shifter. You cannot use the tiller system for that. You also need to change the front bracket out. Where are you located?
 

nelsonag

Recruit
Joined
Oct 5, 2020
Messages
5
You need the linkages for the remote throttle and shifter. You cannot use the tiller system for that. You also need to change the front bracket out. Where are you located?
Lansing, MI
I found the remote conversion online. I am using the schematics from boats.net. Do you by chance have a picture you could send my way to use as a guide?
 

flyingscott

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Apr 8, 2014
Messages
8,154
Lansing, MI
I found the remote conversion online. I am using the schematics from boats.net. Do you by chance have a picture you could send my way to use as a guide?
I will try to get a pic of mine as soon as I can
 
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