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Fuel pump help 1995 johnson 70

M

mconrad70

New member
Having issues getting full throttle. Idles great carbs have been rebuilt, new reeds, all new fuel lines primer ball and check ball on tank. I did put a new fuel pump on and I think that is the problem. The new pump has a vacuum fitting barb and a vacuum port on the back. The rear port goes to nothing on the engine. Is this my issue do I need a pump that does not have that rear port?
 
Stop-----I doubt the new pump is your issue.----Part # of your new pump ?------These pumps operate with a PRESSURE pulse.----The new fuel pump should have 3 nipples , fuel in , fuel out and pressure from the crankcase------You did remove the pulse limiter I hope.----There is no open hole on the back of that pump!!!-----Post the compression values on this motor.
 
racerone said:
Stop-----I doubt the new pump is your issue.----Part # of your new pump ?------These pumps operate with a PRESSURE pulse.----The new fuel pump should have 3 nipples , fuel in , fuel out and pressure from the crankcase------You did remove the pulse limiter I hope.----There is no open hole on the back of that pump!!!-----Post the compression values on this motor.
Click to expand...

This the pump I put on if you notice on back is a port in center. I think I bought the wrong one.
 

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racerone said:
Stop-----I doubt the new pump is your issue.----Part # of your new pump ?------These pumps operate with a PRESSURE pulse.----The new fuel pump should have 3 nipples , fuel in , fuel out and pressure from the crankcase------You did remove the pulse limiter I hope.----There is no open hole on the back of that pump!!!-----Post the compression values on this motor.
Click to expand...

This the pump I put on if you notice on back is a port in center. I think I bought the wrong one. Screenshot_20220531-212334_Chrome.jpg
 
Is there a nipple missing on that pump??----438559 is shown with 3 nipples where I look.---Are you sure the hole on the back goes to the diaphragm ?-----Typical internet seller --Not every 25 year old Amazon clerk has 30 years of outboard expertise.-----Typical.-----the 438556 is the wrong pump for your motor.-----A typical messed up listing I say.----Visit your local dealer for the correct pump !
 
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racerone said:
Is there a nipple missing on that pump??----438559 is shown with 3 nipples where I look.---Are you sure the hole on the back goes to the diaphragm ?-----Typical internet seller --Not every 25 year old Amazon clerk has 30 years of outboard expertise.-----Typical.-----the 438556 is the wrong pump for your motor.-----A typical messed up listing I say.----Visit your local dealer for the correct pump !
Click to expand...

Ok boat is running better but will not run over 4200RPM. What plugs do you suggest and the needle screws on the sides of the carbs are just for idle correct?
 
Motor is not performing.----It was suggested that you post the results of a compression test some time ago.-----I can not see , hear or touch your motor.----Facts about your motor must not be kept secret !
 
racerone said:
Motor is not performing.----It was suggested that you post the results of a compression test some time ago.-----I can not see , hear or touch your motor.----Facts about your motor must not be kept secret !
Click to expand...

I apologize I thought I had posted that:

Compression ranged was 120 on top, 122 center, and 120 on bottom. All three carbs have been rebuilt and reeds replaced with boyeson reeds. All fuel hose have been replaced and sparkplug are currently NGK BPZ8HS-10. Fuel is ethanol free and premixed 50:1
 
Does spark jump a gap of 7/16" on each plug lead ?----Are the high speed jets in the bottom of the float bowl the correct size and clean ?-----Has this motor ever been apart ?----I have a 3 cylinder block like that where one cylinder sleeve rotated and intake and exhaust ports were blocked.----The trouble shooting is easy.----Have I said that before?
 
racerone said:
Does spark jump a gap of 7/16" on each plug lead ?----Are the high speed jets in the bottom of the float bowl the correct size and clean ?-----Has this motor ever been apart ?----I have a 3 cylinder block like that where one cylinder sleeve rotated and intake and exhaust ports were blocked.----The trouble shooting is easy.----Have I said that before?
Click to expand...

Yes on the spark jump the motor I have owned for 10yrs and never taken apart besides the intake this year for the new reeds. Jets I have no idea about but it does appear to be running rich at idle but does not smoke running down lake
 
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