1976 evinrude 4hp fuel pump rebuild or replace with newer model

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Bknboat16

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I have a 1976 evinrude 4hp 4606m , anyone know if thry make a rebuild kit for it or if you could use a fuel pump off one in the 1980's. The fuel pump number is 388684 , i saw a rebuild kit # 393088 for johnson/evinrude 1981 up. Looks like same gaskets in the 76 fuel pump. Does anyone know if kit will work or if a fuel pump from a newer 4hp model will work ? Or if there is another work around?
Thanks in advance
 
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racerone

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Dec 28, 2013
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Likely all you need is a diaphragm 331307.-----Available all day long at about $6.00----There is very little that can go wrong with these pumps !!-----What is your motor doing / not doing?-----Not sure why folks buy new pumps for these simple problems.---Yes that kit will work.-----These little pumps were the same from 1967 to end of production.
 
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Bknboat16

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racerone said:
Likely all you need is a diaphragm 331307.-----Available all day long at about $6.00----There is very little that can go wrong with these pumps !!-----What is your motor doing / not doing?-----Not sure why folks buy new pumps for these simple problems.---Yes that kit will work.-----These little pumps were the same from 1967 to end of production.
Click to expand...
Just put carb kit in, motor not run for years carb was gummed up with old gas and figure the pump might be the same. How long do the rubberized gaskets / diaphrams last in these pumps? What would be the symptoms of a failing fuel pump?
 
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Crosbyman

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no pumping ... no fuel ... no power . no starting etc....

try the pump ... do not fix if it works just clean the screen under the screw cap .


folks may elect to change the pump assembly because openning one up is a real cracker jack box of parts and reassembly is complicated unless you do several. Some kits are as expensive as pumps.
crid=O4WMCU7193BQ&keywords=omc+fuel+pump+rebuild+kit+%23+393088&qid=1676074983&sprefix=omc+fuel+pump+rebuild+kit+393088%2Caps%2C88&sr=8-15



if you do crack one open carefully and watch for flying parts .....small small parts

to reassemble I touch the spring base nipples with crazy glue to hold them in place and..... same for the mushrooms on top of the springs ...I touch them with a small amount of crazy glue.... keeps everything in place while you reassemble the cake layers :)
 
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Bknboat16

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Crosbyman said:
no pumping ... no fuel ... no power . no starting etc....

try the pump ... do not fix if it works just clean the screen under the screw cap .


folks may elect to change the pump assembly because openning one up is a real cracker jack box of parts and reassembly is complicated unless you do several. Some kits are as expensive as pumps.
crid=O4WMCU7193BQ&keywords=omc+fuel+pump+rebuild+kit+%23+393088&qid=1676074983&sprefix=omc+fuel+pump+rebuild+kit+393088%2Caps%2C88&sr=8-15



if you do crack one open carefully and watch for flying parts .....small small parts

to reassemble I touch the spring base nipples with crazy glue to hold them in place and..... same for the mushrooms on top of the springs ...I touch them with a small amount of crazy glue.... keeps everything in place while you reassemble the cake layers
Click to expand...

Crosbyman said:
no pumping ... no fuel ... no power . no starting etc....

try the pump ... do not fix if it works just clean the screen under the screw cap .


folks may elect to change the pump assembly because openning one up is a real cracker jack box of parts and reassembly is complicated unless you do several. Some kits are as expensive as pumps.
crid=O4WMCU7193BQ&keywords=omc+fuel+pump+rebuild+kit+%23+393088&qid=1676074983&sprefix=omc+fuel+pump+rebuild+kit+393088%2Caps%2C88&sr=8-15



if you do crack one open carefully and watch for flying parts .....small small parts

to reassemble I touch the spring base nipples with crazy glue to hold them in place and..... same for the mushrooms on top of the springs ...I touch them with a small amount of crazy glue.... keeps everything in place while you reassemble the cake layers
Click to expand...
Is oem kit better than sierra kit? Also are the aftermarket pumps any good or just a crapshoot? Just want to have one incase it wont run after i get it all reasembled
 
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racerone

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The factory kit comes with instructions.----Easy to follow instructions.------You can use screws ( heads cut off ) to make for " painless work " on re-assembly.----You always have the manual pump as a back up in case of a very rare failure of these simple pumps !
 
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Crosbyman

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Messages
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honestly.. .so far no issues came up with cheaper pumps ... up to you....

I did have some I questionned but in the end they were ok
 
oldboat1

oldboat1

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Before you test that motor, you need to replace the impeller in the lower unit. Drain the oil, and replace with fresh. I'll guess your carb still needs attention if this is your first rodeo. Sounds like it should have been disassembled and soaked in solvent. Low speed needle is set to 1 1/2 turns open initially, about 3/4 open for the lower high speed needle.

After you have the lower unit and carb ready, test the motor in the lake or in a test barrel (big plastic trash can work, half full of water.)
 
oldboat1

oldboat1

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^good info. I differ a little with adjustment -- leaner (c.wise) 1/8 turn until it "lean sneezes" or stalls, then richer by 1/4 turn. (A lean sneeze sounds like a mild backfire.) Use a can of carb cleaner with a plastic nozzle to finish up, then air dry. Use of compressed air can be a little over kill.

The best overview imo is to tune it as lean as you can for proper running (shifts into gear and accelerates without stalling. idles slowly and smoothly.)
 
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