Alright here is the dilemma. I am pretty sure I’m running out of fuel at WOT.
Here is the info I have and what I have done. 1991 Mercury 90/75 Jet. 3 cylinder. This motor ran great all waterfowl season. Since this spring I have bee. Fighting a fuel issue. At first I figured it was just cold blooded as I would leave the dock and it would bog down at wot. I could come off the throttle and it would idle. After a few minutes it would run fine.
The next outing it would run bad again. Primer bulb would feel normal. I could squeeze it and feel fuel. It was not sucking flat. Sometimes pumping it would help. I could put the boat in neutral and idle it high and it would be fine but in forward gear it would give me fits for 15-20 min at wot. So I changed plugs and cleaned the cards.
Next outing the boat would feel better on the bottom. And run wot fir 1/2 then bog down. And do it for 15-20 min the. Run fine. It would continue to do this the next few outings.
I rebuilt the fuel pump and replaced all the fuel lines on the motor. I also replaced the lines from the oil pump to fuel pump. It would run good for a few miles then bog down. I ripped the fuel pump off on the water and double checked everything. Ran good fir 4 straight miles to the dock at wot.
I thought I had fixed it...went out the other morning and immediately it would not run wot. I’d squeeze the primer bulb and it would change anything. So fur the next hour I’d move short distances at 1/4-1/2 throttle. Then o decided to run upriver. It ran wot for 6 miles up then 3 miles back down then bogged down!!!! I put it at 1/4 throttle and was pumping the primer bulb and then after a few min it ran the other 2 miles back to the dock fine.
What is going on?!? I am out of ideas!!! The only thing fuel wise I haven’t changed is the hose and bulb from tank to motor. I just can’t figure out why it’s so hit and miss. Help please.
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Here is the info I have and what I have done. 1991 Mercury 90/75 Jet. 3 cylinder. This motor ran great all waterfowl season. Since this spring I have bee. Fighting a fuel issue. At first I figured it was just cold blooded as I would leave the dock and it would bog down at wot. I could come off the throttle and it would idle. After a few minutes it would run fine.
The next outing it would run bad again. Primer bulb would feel normal. I could squeeze it and feel fuel. It was not sucking flat. Sometimes pumping it would help. I could put the boat in neutral and idle it high and it would be fine but in forward gear it would give me fits for 15-20 min at wot. So I changed plugs and cleaned the cards.
Next outing the boat would feel better on the bottom. And run wot fir 1/2 then bog down. And do it for 15-20 min the. Run fine. It would continue to do this the next few outings.
I rebuilt the fuel pump and replaced all the fuel lines on the motor. I also replaced the lines from the oil pump to fuel pump. It would run good for a few miles then bog down. I ripped the fuel pump off on the water and double checked everything. Ran good fir 4 straight miles to the dock at wot.
I thought I had fixed it...went out the other morning and immediately it would not run wot. I’d squeeze the primer bulb and it would change anything. So fur the next hour I’d move short distances at 1/4-1/2 throttle. Then o decided to run upriver. It ran wot for 6 miles up then 3 miles back down then bogged down!!!! I put it at 1/4 throttle and was pumping the primer bulb and then after a few min it ran the other 2 miles back to the dock fine.
What is going on?!? I am out of ideas!!! The only thing fuel wise I haven’t changed is the hose and bulb from tank to motor. I just can’t figure out why it’s so hit and miss. Help please.
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