1992 88 spl Johnson

hj brown

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I'm having a fuel problem with my motor. Last summer I incurred this problem I can't figure out and was hoping to get help here. The boat has always ran great, no problems ever. I have always disconnected the gas line and ran the motor completely out of gas before taking it out of the water. Last summer the boat was running good as usual, All of the sudden it was like someone turned the gas off. I went to the bulb and it was soft, I pumped it but it would never get hard. I had my son - in - law stay back there and pump the bulb till we made it back to the launch. I use to pump the bulb up before I put attached the gas line to the motor because the tank would condensate and I could let the water of the gas before I plugged it on to the motor. The bulb won't get hard anymore and the old gas line was collapsed so I thought it was the bulb and the gas line, so I went and bought a new gas line and bulb assembly. Should I be able to pump the bulb and it get hard before I attach it to the motor? Wouldn't that tell me if it's in the tank or the carbs? I'm new at working on outboards so I really don't know where to start. I need a little advice on where to start. I took it to the lake yesterday. The boat starts fine, idles fine, runs fine at about 1/4 speed or trolling, but at about half or 3/4 speed it runs out of gas. And the bulb never gets hard.
 

hidef

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Re: 1992 88 spl Johnson

Check the pickup in the tank it sounds like it has a restriction if it is a built in tank run the outboard on a portable tank and see if that cures the issue. The other thing to check is the fuel pump to make sure it isn't getting weak.
 

hj brown

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Re: 1992 88 spl Johnson

my curioscity is this. I used to be able to pump the bulb up to hard before I even put the line to the motor to release water that had condensated in the tank. Which (maybe) tells me it's not the fuel pump? I don't know. The tank on the boat is a 12 ga. metal tank with a breather screw in the lid. Could that be an issue? I have thought about buying a separate tank just to see if maybe it is the tank. The reason I would lean towards the tank is, it's almost like I can hear the bulb pumping into the tank instead of out of the tank. Would this tank have a check valve or something that could be stuck?
 

hidef

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Re: 1992 88 spl Johnson

The hose has a check valve in it. I would check your filters (if you have any), inlets and the pickup. You have a restriction somewhere and that is most likely your problem. A portable tank and new fuel line would eliminate the built in tank and fuel line.
 

hj brown

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Re: 1992 88 spl Johnson

The hose has a check valve in it. I would check your filters (if you have any), inlets and the pickup. You have a restriction somewhere and that is most likely your problem. A portable tank and new fuel line would eliminate the built in tank and fuel line.
So, that means its probably not in the fuel pump, right. I'll have to check the fuel filter I think I seen a filter under the cover. Thanks for all your advice. I'll look at things a little closer when I get home. What are you calling a "pickup" and where do I find it. Sorry, I just don't know much about this motor.
Thanks again
 

hidef

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Re: 1992 88 spl Johnson

The pick-up is the end of the tube in the fuel tank the picks up the fuel. There should be a screen on it and that could also be plugged.
 

emdsapmgr

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Dec 9, 2005
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11,551
Re: 1992 88 spl Johnson

Some assorted thoughts on your fuel problem: You should be able to pump the hose bulb up firm every time. The needle and seats will normally shut the fuel off incoming to the carbs when the bowls fill and the ball valves in the hose should hold pressure in the bulb. Perhaps there is a problem with the floats inside the carbs. Once the engine starts to run, it will suck fuel through the hose and the bulb will get softer-but should not collapse. If it collapses, then the pump is fine and you may have a bad ball valve in the hose or the vent in the tank could be bad. I'd try cracking the cap off the tank slightly in case the breather screw is the problem, though it is unlikely. It is possible that there could be a problem with the anti-siphon valve on the top of the tank. They can acculate grit/debris from gas and once that stainless ball valve gets any dirt on it, it can malfunction. Also, pull the fuel pickup out of the tank and inspect it. If it is plastic, it can become loose at the top and you can suck air. Also, not unknown for them to develop a hole midway down the tube, also causing fuel suction issues. If the fuel pump gets weak, the engine may run fine till you reach some higher rpm-when the carbs need more fuel than the pump can supply-the engine will slow down till the pump catches up, then rev back up again.
 

hj brown

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Joined
May 2, 2011
Messages
4
Re: 1992 88 spl Johnson

Some assorted thoughts on your fuel problem: You should be able to pump the hose bulb up firm every time. The needle and seats will normally shut the fuel off incoming to the carbs when the bowls fill and the ball valves in the hose should hold pressure in the bulb. Perhaps there is a problem with the floats inside the carbs. Once the engine starts to run, it will suck fuel through the hose and the bulb will get softer-but should not collapse. If it collapses, then the pump is fine and you may have a bad ball valve in the hose or the vent in the tank could be bad. I'd try cracking the cap off the tank slightly in case the breather screw is the problem, though it is unlikely. It is possible that there could be a problem with the anti-siphon valve on the top of the tank. They can acculate grit/debris from gas and once that stainless ball valve gets any dirt on it, it can malfunction. Also, pull the fuel pickup out of the tank and inspect it. If it is plastic, it can become loose at the top and you can suck air. Also, not unknown for them to develop a hole midway down the tube, also causing fuel suction issues. If the fuel pump gets weak, the engine may run fine till you reach some higher rpm-when the carbs need more fuel than the pump can supply-the engine will slow down till the pump catches up, then rev back up again.
I would like to thank you for your help.
I went home yesterday, pulled the ell from the tank. I found the pick up tube. What happened was the the tube was sucking from the top where it plugs onto the ell. I cut a little piece off of the tube and put it back on the ell. I put a little gas in the tube and blew on it to see if I could see it leaking again. I didn't see any leaks so I put it back on the tank pumped it up hard, started the motor and let it run for a while and the bulb never got soft. I will take it to the lake and run it to make sure that fixed it. If it does, then I will try and replace the pick up tube(if I can find one).
Thanks for your help again.
Bo
 

emdsapmgr

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Dec 9, 2005
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11,551
Re: 1992 88 spl Johnson

Most marine dealerships sell replacement fuel tank pickups in their shipstores. They come with a new head and a new plastic tube. I probably wouldn't repair one that had leaked-they are fairly inexpensive. All you have to do is swap over the anti-siphon valve.
 
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