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1978 115hp Johnson Carburetor Rebuild

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yogibear924

New member
Looking for any advice on rebuilding my carburetors.
I've had this boat/motor for over 20 years and now need to rebuild the carburetors. I plan on ordering a rebuild kit for each carb.
I have several questions:
A) Does the kit contain all the parts I should need to accomplish this task or is there other items I need to order (It does'nt look like the float assembly is part of the kit). Since this engine is 30 yrs. old, should I replace the float assemblies even if they look ok?
B) Does the kit come with detailed technical instructions?
C) Can or should these carburetors be cleaned by soaking them in a bath of solvent, or is there materials on them that may be damaged if I do this?
D) Are instructions available for the settings / adjustments of the carburetors after installation?
Any advice or words of wisdom would be greatly appreciated!
Thanks,
Yogibear924
Wisconsin
 
A) The kit should have everything you need except the float, will have to order that extra. They should be the foam type float, will last forever most of the time, I would probably replace them just for piece of mind.
B) All of the kits I have ever used came with instructions.
C) If the carbs are not full of crud, you could probably get by with spray cans of carb cleaner. Just make sure you use a piece of fine wire to clean the high speed jets. Make sure ALL passages are cleaned.
D) Your carbs have fixed jets, no adjustments to make.
WORDS OF WISDOM: Get yourself an OEM mnaual, costs a little more but well worth the money. It will help you with any and all repairs. You can always come back here for assistance, lots of people here to help.
 
Thanks for your prompt response, it is greatly appreciated!
I have several more questions that maybe you can answer:
A) Is there a specific part number for the foam type floats? Can these be ordered online or should I get them from an OEM Dealer?
B) Are there any torque specs to follow when I install these carburetors? Should a low strength locktite be used on the
screws to prevent loosening due to vibration?
C) Is there a specific brand of rebuild kit that is better than others? I have seen some posts that complained of thin gaskets
in some of the rebuild kits. Should a gasket sealant be used in addition to the gaskets, or should they be used plain?
D) Where can I obtain an OEM Manual? Online or from a dealer?
E) I was told that some of my problems may have been caused from using gas containing ethanol. I try to use only premium
grade and avoid any that contain ethanol, but this is not always possible. Is there any additives you can recommend using when the only fuel available contains ethanol?

I will definitely purchase an OEM Manual and am sure to find many answers to my questions within the instructions.
Thanks again for your advice!
Yogibear924
 
A) Float = 383437, carb kit = 383906 changes to 439076. I think the float for your engine has always been the foam type, never used the cork type. Parts can be ordered at many online sources, including right here at marineengine.
B) I have never worried about torque specs on the carb bolts, just use common sense and tighten them securley. I am sure there are torque specs in the OEM manual.
C) There are several brands available. I have used sierra and OMC kits with good success. The only thing wrong with sierra is that sometimes the kits are made to cover several applications and you might have some parts left over. Do not use any sealer on carb gaskets, install them dry.
D) It is awfully hard to get gas without ethanol. Newer fuel lines are resistant to it, I try not to use it but sometimes it can't be helped. I run Sea-Foam in all of my engines, outboard, chainsaw, lawnmower, motorcycle, all the time. Helps keep carbon down and preserves the fuel if I get cought late in the year.
E) Outboardbooks.com sells copyrighted manuals, sometimes you can find a deal on Ebay, use your model number to order to make sure you get the correct manual.
 
Carburetor kits are common for many years,.----But why are you looking at the carburetors first ?-----What is the history on this 45 year old motor ?-----I would do a complete evaluation of this motor before spending any coins on it.----What is this motor doing / not doing ??
 
mertkaj said:
I just picked up a boat with the Johnson 115HP model # 115ETL78C. Will the carb kit mentioned above work with my engine as well
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racerone said:
Carburetor kits are common for many years,.----But why are you looking at the carburetors first ?-----What is the history on this 45 year old motor ?-----I would do a complete evaluation of this motor before spending any coins on it.----What is this motor doing / not doing ??
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It was taken to a local marine shop. The compression tested at 126 on all cylinders. They said the carbs need rebuilt.
 
0439076 fits from 78 to 98 models.----Simple job.-----Install a new water pump impeller too.-----Test overheat warning horn.
 
Each carb has 2 of these little screws. One on each side. One is missing. Do you know what the part number would be for this little guy?
 
You need 2 kits.---You have to wonder why screws are missing on a carburetor.-------Not hard to find a drain screw for a " cold one " here.
 
racerone said:
You need 2 kits.---You have to wonder why screws are missing on a carburetor.-------Not hard to find a drain screw for a " cold one " here.
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It was an orfice screw that was missing. The marina guys noticed when they were diagnosing it. I ordered the carb kits and that screw. I’ll let you know how it goes when I receive the parts. Thanks for your help!
 
Yes ----I know what one of those carburetors looks like.-----Might have 20 or more laying around.-----One is called the orifice plug ( high speed jet) and other one on the outside is a drain plug.-----Good luck with this motor.
 
racerone said:
Yes ----I know what one of those carburetors looks like.-----Might have 20 or more laying around.-----One is called the orifice plug ( high speed jet) and other one on the outside is a drain plug.-----Good luck with this motor.
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It was the orfice plug. I ordered on and it was $50! Hopefully everything goes ok when I get everything put together. I’ll keep you informed. Thanks for all your information. It was very helpful!
 
The fuel metering ORIFICE PLUG is listed at $19.99 and for the drain plug I would use a screw from the hardware store at $0.29 ---read 29 cents or less !!
 
Could anyone tell me what part number I would use to replace my coils on 1978 Johnson 115hp v4? I’m trying to research it but I’m not getting accurate info. Thanks!
 
racerone said:
The fuel metering ORIFICE PLUG is listed at $19.99 and for the drain plug I would use a screw from the hardware store at $0.29 ---read 29 cents or less !!
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Could anyone tell me what part number I would use to replace my coils on 1978 Johnson 115hp v4? I’m trying to research it but I’m not getting accurate info. Thanks!
 
I was just curious. I’m learning everything I can about this engine in case something ever happens in the future that I need to replace something
 
Many of the consumable parts are easy to find.-----But many dealers will say ---" they do not make Johnson any more.---You can't get parts. "----Try to sell you a new high tech motor.
 
racerone said:
Many of the consumable parts are easy to find.-----But many dealers will say ---" they do not make Johnson any more.---You can't get parts. "----Try to sell you a new high tech motor.
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They definitely won’t get that out of me. I love this 1978 Johnson. Runs fantastic!
 
mertkaj said:
I was just curious. I’m learning everything I can about this engine in case something ever happens in the future that I need to replace something
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You can get nearly all the parts you would need for this engine right here at MarineEngine.com. I've ordered most of my Evinrude parts from here for many years and have always been satisfied with the quality, price, and quick shipping.

1978 115HP Parts List
 
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