Carb on Johnson 100 hp question

Dm82

Seaman Apprentice
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Jul 30, 2008
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So here goes another question that Im sure someone will read and say how dumb, but I need to learn so I am asking. My question has to do with the carb on a 68 Johnson V100 v4tl-14b. When I look at the carb it looks nothing like what I see in all other carb cleaning references. Its like 4 carbs stacked vertically or something. If someone knows a little about this particular carb please explain to me or point me to some reference material. Again I am new to boat motors and am trying to learn so any help would be more than appreciated. Thanks
 

F_R

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Jul 7, 2006
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28,226
Re: Carb on Johnson 100 hp question

It is exactly what you describe, four carburetors in one casting. My advice is if it must be disassembled, so be it. However, if you can avoid it, so much the better. Kits are rare and extremely expensive. The gaskets are complex and kind of tough to make yourself. A special tool is required to set the float heights.

The high speed orifices (jets) are accessable from the front without taking the carb apart. I suggest removing them and see if there is any sign of gum or crud in them. If there is, then you are in for a teardown and rebuild. If absolutely clean, put them back and see if you can get by without a major job.
 

Dm82

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Jul 30, 2008
Messages
31
Re: Carb on Johnson 100 hp question

So thanks for the clarification. I am looking at the diagram you directed me to (by the way its a big help) and I see the #33 needle valve but the #4 is a screw. Is this correct? Is the #4 screw the low speed? I just dont understand how that could be. And what do I need to disassemble to check for gunk? Thanks again.
 

tashasdaddy

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51,019
Re: Carb on Johnson 100 hp question

basically as F_R said, remove the #4 jets and clean them and the #33, squirt carb cleaner in them, then blow thur the with compressed air. you may need packing for the #33
#33 is the low speed adjustable jet there is one for each carb.

directions for setting are in the TOP SECRET FILE. 1st post in the forum.
 

JB

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Mar 25, 2001
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45,907
Re: Carb on Johnson 100 hp question

No disrespect to the guys who are trying to help, DM82, but anyone would be a fool to tackle that compound carb without the factory Service Manual, no matter who is helping out.
 

tashasdaddy

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51,019
Re: Carb on Johnson 100 hp question

agree!! that is why i gave you a link to buy a manual.
 
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