It doesn't matter which hole you plug, because one hole goes only to the top piston and the other hole goes only to the bottom piston. Normally the rubber flappers (check valves) allow air to flow outward but not inward so alternating piston strokes of the two pistons combined creates a steady outward flow of air to pressurize the fuel tank, but without a check valve air moves both in and out causing pressure on one stroke and vacuum on the next stroke which is the "pulse" needed to move the fuel pump diaphragm in and out in order to pump fuel which it wouldn't be able to do without both an inward check valve and an outward check valve inside the fuel pump itself. One or the other hole in the reed plate must be plugged as shown in this video, because otherwise one piston would suck air in while the other would blow air out which would cancel each other and defeat the goal. btw: the metal reed/check valves work exactly as described above except their job is to let air only inward through the carb instead of outward to the fuel tank which happens simply because they are mounted on the piston side of the reed plate instead of the carb side. The reason for the material and size differences should now be obvious.
I bought a fuel pump and fuel line. Everythign i can find online for fuel pumps have a 1/4" outside diameter. The carb on my 57 7.5 Johnson has a 1/8" outside diameter. Did you have this same problem?
Your videos are great -- just picked up a '57 seahorse 7.5 and excited to get it converted. You don't happen to have a parts list of what's required to do this, do you? definitely going to be watching all your videos!
Does it matter if you do the left or right side? I plugged the opposite side that you plugged. Figured it would be better for the hole closest to the connector to be unplugged. Gas only trickles out when pulling the starter to cause the pulse (not connected to carb for testing). I didn't get the mikuni pump (spellcheck) but it had a good rating on Amazon. Figured bad pump or I plugged the wrong side. Any thoughts?
Yeah I’m not sold on which side is better. I need to do more conversions. I’ve been going with the Briggs and Stratton pumps and from my 2 success stories… they idle great in the barrel, don’t test the high speed until the water and make sure you bring a backup motor!!
@@BlackoutBilll21 i ordered the "KIPA Single Outlet Fuel Pump For Mikuni Rectangle DF-44 DF44-211 Single carb snowmobile Replace Nachman 07-187-01 Personal watercraft 14 liters Per Hour" and I already had fuel in the pulse so they are sending me another one. I'll let you know if the replacement one does any better.
@@BlackoutBilll21 I got impatient so I tore the old one apart and got it back functioning again. Shortened all my lines and made some other adjustments with what they were seated with. Closed my low speed a bit more and finally got it running for the first time! My first outboard. Didn't even know what a point was going into it haha. 1958 5.5hp 5516 Fisherman. Appreciate the advice. I'll definitely make a video and post it tomorrow when I take it out. Even if it runs half ass I'll still post it for some feedback. Appreciate the advice!
Great Video! I was just going to buy a pressure tank, but you opened my eyes alot about how to actually do the conversion, so thank you. What size line did you use for all 3 lines? (Input/output/vacuum) thanks!
Does anyone know if such a conversion can be made to a 1959 Evinrude 5.5 hp? I read somewhere that there may not be room to add a fuel pump to this smaller size engine.
I converted my 1958 5.5hp. I just zip tied it to a tucked off area on it. Its snug for sure when I put the lid back on because of the pulse line but its doable.
you should always tighten inside out the reason being a tightening sequence is to eliminate the chance of creating a wrinkle in the gasket if you tighten outside in their is no where for the wrinkle to go if you tighten it inwards if you tighten in to out it pushes the wrinkle to the outside and eliminates it
Jed Bichsel absolutly!!! Sorry the day I water tested it after installing a new impeller, housing, gear case, and coils...I left my phone at the dock! lol it's my favorite running motor now! Works like a champ!
I have a 1956 30 HP that I am converting to non pressurized - I was wondering if I just plug the air line instead of pulling the carb off and plugging the reed plate, it that would work I saw someone once mention that If you just put a bolt in the line and a clamp you don't need to remove the carb . Is the pump you used on Mukuni knockoff from Hong Kong (china) - I ordered one of those as too for 10 bucks. Your thoughts
Jed Bichsel I was told plugging the one side of the air pressure line does NOT work. I would check iboats for more specific info on that... As far as the fuel pump I used... I thought it was the original brand... I paid 25 bucks and believe the name was milkini. But whatever the brand it works flawlessly
Basically the brand fuel pump shouldn't matter. I've seen Briggs and Stratton pumps work fine but be carful. Research to make sure they will support a 30 hp.
It doesn't matter which hole you plug, because one hole goes only to the top piston and the other hole goes only to the bottom piston. Normally the rubber flappers (check valves) allow air to flow outward but not inward so alternating piston strokes of the two pistons combined creates a steady outward flow of air to pressurize the fuel tank, but without a check valve air moves both in and out causing pressure on one stroke and vacuum on the next stroke which is the "pulse" needed to move the fuel pump diaphragm in and out in order to pump fuel which it wouldn't be able to do without both an inward check valve and an outward check valve inside the fuel pump itself.
One or the other hole in the reed plate must be plugged as shown in this video, because otherwise one piston would suck air in while the other would blow air out which would cancel each other and defeat the goal.
btw: the metal reed/check valves work exactly as described above except their job is to let air only inward through the carb instead of outward to the fuel tank which happens simply because they are mounted on the piston side of the reed plate instead of the carb side. The reason for the material and size differences should now be obvious.
Absolutely love these comments! Thanks for the explanation!! Feel free to comb through the rest of my videos and do more!!
I bought a fuel pump and fuel line. Everythign i can find online for fuel pumps have a 1/4" outside diameter. The carb on my 57 7.5 Johnson has a 1/8" outside diameter. Did you have this same problem?
dont worry about the diameter just make sure the hose fit around the nipple properly :)
Your videos are great -- just picked up a '57 seahorse 7.5 and excited to get it converted. You don't happen to have a parts list of what's required to do this, do you? definitely going to be watching all your videos!
Appreciate you my guy!! I believe I can assemble everything you need! Give me a day or so! Thanks for the sub!!!
fuel pump - amzn.to/3jM97mK
fuel connector amzn.to/3AxoWVq
It is NOT a vacuum it is however pulse and vacuum.Both are required to operate diaphragm in fuel pump......
Thanks for the clarification!! and thanks for watching!
Does it matter if you do the left or right side? I plugged the opposite side that you plugged. Figured it would be better for the hole closest to the connector to be unplugged. Gas only trickles out when pulling the starter to cause the pulse (not connected to carb for testing). I didn't get the mikuni pump (spellcheck) but it had a good rating on Amazon. Figured bad pump or I plugged the wrong side. Any thoughts?
Yeah I’m not sold on which side is better. I need to do more conversions. I’ve been going with the Briggs and Stratton pumps and from my 2 success stories… they idle great in the barrel, don’t test the high speed until the water and make sure you bring a backup motor!!
@@BlackoutBilll21 i ordered the "KIPA Single Outlet Fuel Pump For Mikuni Rectangle DF-44 DF44-211 Single carb snowmobile Replace Nachman 07-187-01 Personal watercraft 14 liters Per Hour" and I already had fuel in the pulse so they are sending me another one. I'll let you know if the replacement one does any better.
@@DiabolicalDesigns cool!
@@BlackoutBilll21 I got impatient so I tore the old one apart and got it back functioning again. Shortened all my lines and made some other adjustments with what they were seated with. Closed my low speed a bit more and finally got it running for the first time! My first outboard. Didn't even know what a point was going into it haha. 1958 5.5hp 5516 Fisherman. Appreciate the advice. I'll definitely make a video and post it tomorrow when I take it out. Even if it runs half ass I'll still post it for some feedback. Appreciate the advice!
@@DiabolicalDesigns hey man that’s awesome!!! Hell yeah send me the progress!!!!
what fuel connector did you get for the engine
typical OMC evinrude johnson connection. Should be 3/8ths search on ebay!
Great Video! I was just going to buy a pressure tank, but you opened my eyes alot about how to actually do the conversion, so thank you. What size line did you use for all 3 lines? (Input/output/vacuum) thanks!
Peter Seyler it's a smaller line not sure of exactly the size ... Good luck!
1/4"
@@billwhitmeyer3861 Thanks Bill!
were was the intake vacum connection? Thanks!
aandjwynn you plug it up! It’s on the intake manifold itself. once together plug the tit
k thanks
Does anyone know if such a conversion can be made to a 1959 Evinrude 5.5 hp? I read somewhere that there may not be room to add a fuel pump to this smaller size engine.
Pamela Wright Absolutly can be done
I thought they stopped the duel line in 1958?
I converted my 1958 5.5hp. I just zip tied it to a tucked off area on it. Its snug for sure when I put the lid back on because of the pulse line but its doable.
you should always tighten inside out the reason being a tightening sequence is to eliminate the chance of creating a wrinkle in the gasket if you tighten outside in their is no where for the wrinkle to go if you tighten it inwards if you tighten in to out it pushes the wrinkle to the outside and eliminates it
gabriel falan awesome tip! Thanks
Your voice sounds so much like mine that I thought I accidentally clicked on a video I made. Weird.
did it ever run correctly?
Jed Bichsel absolutly!!! Sorry the day I water tested it after installing a new impeller, housing, gear case, and coils...I left my phone at the dock! lol it's my favorite running motor now! Works like a champ!
Jed Bichsel here is a link of it running before I fixed the gear case ua-cam.com/video/pGIATay2azU/v-deo.html
I have a 1956 30 HP that I am converting to non pressurized - I was wondering if I just plug the air line instead of pulling the carb off and plugging the reed plate, it that would work I saw someone once mention that If you just put a bolt in the line and a clamp you don't need to remove the carb . Is the pump you used on Mukuni knockoff from Hong Kong (china) - I ordered one of those as too for 10 bucks. Your thoughts
Jed Bichsel I was told plugging the one side of the air pressure line does NOT work. I would check iboats for more specific info on that... As far as the fuel pump I used... I thought it was the original brand... I paid 25 bucks and believe the name was milkini. But whatever the brand it works flawlessly
Basically the brand fuel pump shouldn't matter. I've seen Briggs and Stratton pumps work fine but be carful. Research to make sure they will support a 30 hp.