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1990 Sea-Doo SP with Electric Fuel Pump Question

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Brigganator

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Hello i am brand new to this forum and to Sea Doo's, i picked up a 90 sea doo sp 587? and been having issues with it running without having to use the choke, so i troubleshooted and found out the issue was the fuel pump, so i decided to purchase a electric fuel pump and tested it and now it runs great! only problem now is wiring it in correctly, i checked out the wiring guide in the manual and was thinking of possibly hooking the positive end to somewhere on the tether switch cause that is the only location in my opinion that would be giving off some volts when its running, or my other option would be purchase a switch and just wire it in that way so the pump isnt running 24/7. any suggestions would be greatly appreciated! thanks!:thumbsup:
 
Brigganator said:
Hello i am brand new to this forum and to Sea Doo's, i picked up a 90 sea doo sp 587? and been having issues with it running without having to use the choke, so i troubleshooted and found out the issue was the fuel pump, so i decided to purchase a electric fuel pump and tested it and now it runs great! only problem now is wiring it in correctly, i checked out the wiring guide in the manual and was thinking of possibly hooking the positive end to somewhere on the tether switch cause that is the only location in my opinion that would be giving off some volts when its running, or my other option would be purchase a switch and just wire it in that way so the pump isnt running 24/7. any suggestions would be greatly appreciated! thanks!:thumbsup:
Click to expand...

Fuel pumps require a decent amount of amps. I would think the tether draws pretty low amps.

You stand a very good chance of damaging something on the tether line or the brain (assuming the 90 model has one).

You could use the tether line as a trigger that would operate a relay that would then power the fuel pump. To turn on a relay requires very little amps but the relay can feed high amp items.
 
Did you check your fuel pick up. They seem to corrode and break off, could be why you were not getting fuel.
 
kicker said:
Did you check your fuel pick up. They seem to corrode and break off, could be why you were not getting fuel.
Click to expand...

Yes vacuum tested the fuel lines to see if i was getting fuel and it was, the pump works great and the doo runs good but just need advice one how to hook the pump up permanently, might just wire a switch in and call it a day rather than taking the chance and frying something in the tether system. any recommendations on what amp toggle switch i should get?
 
I really dont understand the need for a electric fuel pump...but if thats the route you are taking, yes...just hard wire it.
 
Brigganator said:
Cause reliability is much better than stock in my opinion, what amp switch is ok to use ?
Click to expand...

If possible find out the amp reading of the fuel pump.

When in doubt, go big on the switch and probably put a 20 amp fuse in line. I'd try a 15 amp fuse first, then go to 20 if need be.
 
I feel a responsibility to give you proper advice and I feel like you are going about it all wrong. Forcing fuel to the engine is not a permanent solution. It is merely masking the usual and solvable problems that a 23 year old fuel system has.

1) There are two little fuel pick-ups on the end of flexible lines inside your fuel baffle. They fall off rotted lines(as mentioned above) but they also like to gum up. There are little check valve balls inside them.

2) The fuel lines themselves can be loose on the fittings allowing air to be drawn in.

3) The fuel selector has a rubber seal inside it that shrinks up and allows air to be drawn in. Or it could be partially restricted from old fuel.

4) The carb has a internal filter that can easily plug up and restrict fuel.

5) At this point I would not trust the diaphragms in the carb and fuel pump. They get crispy and can't fluctuate properly to do the job they were designed for.
 
Matt has given good advice.

Every item he mentioned is a common failure item.

I would take a very good look at the items mentioned as even if you do the electric fuel pump these items can be weak and fail

I would NOT wire it direct as it will pump even if the engine shuts down. If you still want to go the pump route, I strongly suggest jumping off a feed wire that is ONLY hot when the engine is running. Use a relay to protect the load on the jumper wire.
 
On a 1990, there really isnt a brain or many wires that you can tether off of. I would use a 30 amp relay, and a 15A fuse. Get the trigger off of the voltage regulator output wire and you may require a diode. That way when the engine is running, the regulator is supplying the little voltage for the relay to create the circuit.

But I don't understand... A carb kit and some carb cleaning is far cheaper than an electronic fuel pump+relay+wire+switches+waterproof/shrinkwrap crimp connectors, etc) Heck, check the pulse line from the crankcase, it may have a hole in it or is dry rotted.
 
I'm not that familiar with older ski's myself, but I believe a 90 SP used a separate fuel pump and a Klien carburetor, but I also think the fuel pump was mechanical and ran off the pulse line.

Lou
 
I believe you are correct lou, i also will be replacing all the fuel lines before next season, just doing 1 step at a time. i had a buddy of mine come over to help me out with the doo and like i said before we could get fuel from the tank with the vacuum tool and but once it was hooked up to the stock fuel pump we got nothing, and we also checked to see if there was a pulse coming from the motor to drive the suction from the tank to the pump then to the carb but still didnt get anything, rather than trying to find a used or new fuel pump for it we decided a electronic pump would be the easiest solution but of course running into the problem of what if someone falls off.. the sea doo will shut off but the pump will still be running unless you someone flip the switch before falling off.. maybe i should consider different options unless i can find another tether switch and somehow run 2 hookups, 1 for the tether switch to shut off the motor and 1 to shut off the pump when you fall off. heres a link of the idea i was thinking of. let me know what u guys think. thanks

http://i27.photobucket.com/albums/c173/Brigganator/tetherswitchpic_zps74a3b0ec.png
 
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I think that a fuel pump is DANGEROUS! If you have a leaky fuel line somewhere it will drip under pressure. The fuel lines were designed for NO PRESSURE. I think you should fix carb and it will suck the fuel you need without issues. Safety first....even a brand new carb is cheaper than your plan.
 
problem is i cant get any fuel to the carb, its like the pulse from the motor thats suppose to push the fuel from the tank is not working.. if anyone thinks i should just get a new stock pump maybe that would work? but problem with that is they dont make them! and buying one used is a risk... and besides that pump is only pushing 3-4 psi its not like its going to leak somewhere especially when i replace all the fuel lines anyways..
 
You asked what I think, I think if I were you I wouldn't give up my day job to become an artist. :reddevil:

Lou
 
OK. I am a master mcgyver. So what you are trying to do CAN work and i will tell you how to do it SAFELY. Would i do it.... well you've already invested in the pump and time...its an old ski, so maybe if it were a personal beater ski. I would never do this to a customer, or family/friend. You have 3 options. Regardless the carb(s) will have to come apart. It is most likely the fuel filter.

I will highly recommend that you get a carb kit, or at least put a vacuum gauge on the pulse line and make sure that you are getting a good pulse (replace the line first). Then inspect the check valves, etc in the original fuel pump. Return the fuel system to its proper tried and proven design which would be my first choice.

Next choice, because you invested in the electronic pump, you will need an inline 15A fuse, 30A relay and a minimum of 14 gauge wire. Heat shrink crimp connectors and/or heat shrink and solder. As I said earlier in a previous post, I would connect to the voltage regulator. However, if the regualtor failed, you would be dead in the water....
But with a test light, you can see if you can find a wire either going to the coil, or CDI which is ON with the tether, and OFF when pulled, or get another tether and link the two together as you showed... snowmobile shops have them.. they are about 10$ you need a "closed" circuit when depressed, and "open" when the tether is pulled.

Third option. Go to a skidoo shop and get an OEM mikuni stand alone pulse fuel pump. Install that before the carbs, and plumb it into the "inlet". This would guarantee proper PSI and flow to the carbs, and has the same principal as the OEM set up.

EDIT: The electronic fuel pump may draw too many amps and may drain the battery faster than the charging system can keep up. SO you may kill the battery while riding! Food for thought!
 
Your electrical system may not keep up with an electric fuel pump.


Just rebuild the mechanical pump, and run it properly.
 
No need for instruction...just open it up and pay attention to how it comes apart. You will find that the little flaps that pump the gas will be eaten away in there.

Heres the kit...In his description it says mikuni, so it should be legit. Aftermarket rebuild kits suck. If it doesnt come in a Mikuni package I would send it back.

http://www.ebay.com/itm/Mikuni-MK-D...Parts_Accessories&hash=item19e43219ad&vxp=mtr

And Lou although the pro he is....is mistaken. ;) Seadoo never used keihin carbs. 88-90 they used the BN carb with a seperate fuel pump. 91 they went to the SBN carb, which is a HUGE upgrade to the BN. Typically the SBN has its own fuel pump, but can be setup to use an external pump.


Now...if it were my machine and I was planning on using it more than a beater I didnt have to rely on...I would just check and rebuild the fuel pump and clean the carb.

If its going to be more than that....buy a SBN carb off a 91-94 SP, and clean/rebuild it with a Genuine kit. Toss the old fuel pump and carb. If you get a 91-94 SP its jetted to drop right on your machine and improves starting and performance. Also all linkage hooks up without modification. Then from there you can buy a SPI tuned pipe/WB and rejet the carb to the SPI specs for even more power.

The reason I know all this....its fresh. I got a 90 running for ice riding this spring and it was a big difference. BUUUUUUUUUUUUUT.....the #1 thing you need to check aside from the carbs is the cooling system. On the exhaust outlet there are two fittings. The one connected to the 1/2 line on the side of the head....take the fitting out of the outlet and check for obstruction. Clear it and run a drill bit through it a few sizes bigger to keep things from jamming in there. Very typical problem on the oldies...
 
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Minnetonka4me said:
No need for instruction...just open it up and pay attention to how it comes apart. You will find that the little flaps that pump the gas will be eaten away in there.

Heres the kit...In his description it says mikuni, so it should be legit. Aftermarket rebuild kits suck. If it doesnt come in a Mikuni package I would send it back.

http://www.ebay.com/itm/Mikuni-MK-D...Parts_Accessories&hash=item19e43219ad&vxp=mtr

And Lou although the pro he is....is mistaken. ;) Seadoo never used keihin carbs. 88-90 they used the BN carb with a seperate fuel pump. 91 they went to the SBN carb, which is a HUGE upgrade to the BN. Typically the SBN has its own fuel pump, but can be setup to use an external pump.


Now...if it were my machine and I was planning on using it more than a beater I didnt have to rely on...I would just check and rebuild the fuel pump and clean the carb.

If its going to be more than that....buy a SBN carb off a 91-94 SP, and clean/rebuild it with a Genuine kit. Toss the old fuel pump and carb. If you get a 91-94 SP its jetted to drop right on your machine and improves starting and performance. Also all linkage hooks up without modification. Then from there you can buy a SPI tuned pipe/WB and rejet the carb to the SPI specs for even more power.

The reason I know all this....its fresh. I got a 90 running for ice riding this spring and it was a big difference. BUUUUUUUUUUUUUT.....the #1 thing you need to check aside from the carbs is the cooling system. On the exhaust outlet there are two fittings. The one connected to the 1/2 line on the side of the head....take the fitting out of the outlet and check for obstruction. Clear it and run a drill bit through it a few sizes bigger to keep things from jamming in there. Very typical problem on the oldies...
Click to expand...






will this fuel pump work? this guy is in my area so i could have this by tommorrow or sat.. and hopefully it works.. thanks
 
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
What fuel pump...? The one on the sbn carb? Yup it gets hooked to the pulse line. I've personally never seen a pulse line not work; there would have to be blockage.

Sent from my SGH-T989 using Tapatalk
 
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