80s looper carb advise! Help

Joined
Apr 26, 2017
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21
Ok guys, I replaced the powerhead on my 1986 evinrude 140 looper last summer. (TLCDC) I got the remanufactured powerhead from crowley marine which specified it as a 85-88 model. After a summer of being underwhelmed with the power the boat (19ft starcraft Eagle) has I decided to start looking more closely at the carburetors. From what I can tell the carbs that were on my 86 and now on the new powerhead are the model from 1988 because on the OMC parts catalog I found this matching number "432513".

The orifice jets installed on my carbs are as follows: No. 1- 42, 28 and 63d , No. 2- 42, 28 and 63d , No. 3- 45, 28 and 63d , No. 4- 45, 20 and 63d.

My question is on the parts catalog it says port and starboard carbs would be different sizes for a 1986, but mine has different sizes for top 2 cylinders and bottom 2. But since my carbs match up with an 1988, it says 41 idle air, 54 intermediates and 63d mains. Which jetting configuration should I be following?? Because either way the current jetting isn't correct and the boat has a hard time getting on a plane.
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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86 is a small bore block and is jetted .002 smaller. The big bore uses 63 jets....need to find out bore size.
 
Joined
Apr 26, 2017
Messages
21
The powerhead is a 85-87 1.8 liter block. racerone I need to find out what are the throat measurement to determine what carbs I have. I have 2 sets, one set seems to be from a 87 120hp. The other set that is installed seems to be 88 140 carbs. I don't know the difference between mid bore and big bore carbs.
 

racerone

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Dec 28, 2013
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I would have to take carburetors off a 140 and off a 120 model to help.----Not going to happen without a case of cool ones .----Sorry.
 
Joined
Apr 26, 2017
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I understand. Do you happen to know if hand if there were any differences in the carb bodies between the 87 1.8 liter and the 88 2.0 liter?
 

Faztbullet

Supreme Mariner
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Mar 2, 2008
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15,937
Throttle bodies and carb bodies are different between 120 and 140..its da the venturi. You can take 2 finger and stick in the throats and feel the difference.
 
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