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Discussion Starter #1
I bought an Ultra 21 LX open bow last year. It has a Mercury 2.5L XRi EFI (200 hp - 1992 model) that does not have an electric fuel pump. It is running on the old vacuum system whereby you pump the bulb and then the vacuum created by the engine pulls the gas from the tanks. It has twin saddle tanks running to a tank selector valve. From there it goes to the water separating fuel filter and then to the engine.

I have had issues with the engine starving for fuel. Mostly this occurs at low RPM. Idle long enough and it will die. Mostly runs fine once on plane. Periodically it will die when you pop it on plane after some idle time. Pump the bulb again and it runs fine till the next idle session. This is tricky around the launch ramp if you have to idle for a while :|err

On my 19' tunnel / bridgeport combo, I have a holley blue fuel pump running 3.5-4 psi . However, the bridgeport is a carburated engine. This set-up has always ran well for me.

My questions concerning the Ultra 21' are:

1. Should I install an electric fuel pump with regulator or is there a better method than an electric fuel pump?
2. What PSI should an EFI 200 be set at?
3. If an electric pump is needed, what fuel pump is recommended?
4. How do I wire it so that the fuel pump turns on when the key is turned on to the auxillary postion? Cut into the ignition hot?

Thanks.
 

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Baller on a Budget
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My dad has that same motor and it has a stock electric fuel pump on it. He has had the motor since it was new and has never had to pump the bulb. Once you turn the key you should hear it turn on. I have a '93 200 2.5 carb motor and it has a mechanical fuel pump. Im almost positive yours should have an electronic fuel pump. Next time I'm over there I'll check it out a little closer. But it does sound like a fuel pump issue. How does it run at wot?
 

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Discussion Starter #3
How does it run at wot?
Not like my 19' Daytona :p No serious, it runs fine at WOT. About 5,500 RPM turning a 4 blade 14.5x21. Engine runs great. Starts right up every time. It is definitely a fuel delivery issue or the bulb wouldn't be empty when the engine dies. Pump the bulb and it fires right back up.

Does your dad's boat have a Mercury electric fuel pump?
 

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rollin on the river
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Not like my 19' Daytona :p No serious, it runs fine at WOT. About 5,500 RPM turning a 4 blade 14.5x21. Engine runs great. Starts right up every time. It is definitely a fuel delivery issue or the bulb wouldn't be empty when the engine dies. Pump the bulb and it fires right back up.

Does your dad's boat have a Mercury electric fuel pump?
Sounds like a leak somewhere.
 

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two strokes is enough
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remove your bulb and see if it allows fuel both ways? cbass here on the boards had the same issue your talking about and his bulb was worn out it allowed fuel to pass either way so we ran down river bought another and it ran fine all the way home and still runs great
 

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Discussion Starter #7 (Edited)
remove your bulb and see if it allows fuel both ways? cbass here on the boards had the same issue your talking about and his bulb was worn out it allowed fuel to pass either way so we ran down river bought another and it ran fine all the way home and still runs great
Thanks for the heads up. I guess you never know what you get with a used rig. I could replace the gas lines all the way around to eliminate that as an issue. Come to think of it, I shouldn't have to pump the bulb 7 or 8 times. Last year it seems the bulb only needed to be pumped 3-4 times before you couldn't pump it anymore. Now I can pump it 7-10 times and keep going if I wanted. Makes me wonder if after a few pumps it isn't starting to dump gas the other way? :confused:
 

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rollin on the river
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I can check that easy enough. Your boat has a 2.5L 200 hp correct? Did your engine come standard issue with an electric fuel pump from Mercury?
my 200 was a frankenstien. But it had an electric. Now I have a 225 promax.
 

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two strokes is enough
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Thanks for the heads up. I guess you never know what you get with a used rig. I could replace the gas lines all the way around to eliminate that as an issue. Come to think of it, I shouldn't have to pump the bulb 7 or 8 times. Last year it seems the bulb only needed to be pumped 3-4 times before you couldn't pump it anymore. Now I can pump it 7-10 times and keep going if I wanted. Makes me wonder if after a few pumps it isn't starting to dump gas the other way? :confused:

just an idea my 2.5 has a fuel pump but my buddy cbass has a bulb and we figured that out on the sandbar and had to make a quick trip so we didnt have to tow him back
 

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Baller on a Budget
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Ya there is a small electric fuel pump inside the cowling. I talked to him tonight and he said hes never replaced it either. He said you should hear it turn on when you turn the key and it takes a couple seconds to prime and then it should fire. And pumping the bulb 7-10 times is way to much you are loosing fuel somewhere. Like you said 3-4 pumps is all it should take. I actually just had a cracked fuel line on my motor on the hose clamp right at the fitting that plugs into the motor. I noticed it one day when I went to pump the bulb and fuel started shooting out of the line. So I would replace you fuel lines and bulb first(cheap insurance) cause if that is the case and you are sucking in air you rmotor is running lean which is never a good thing. Do you smell any gas or see any leaks when you pump the bulb? Also how are you gas tanks vented? That would also cause it suck dry of fuel.
 

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info

if it is really an xri efi, it does have a highpressure pump, it is located on the front right side of the engine. the low pressure diaphram pump feeds the resivour that feeds the high pressure pump. likely the diaphram pump could use a rebuild kit, and you need to replace the primer bulb. your efi system runs at 39 psi, good luck
 

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Discussion Starter #12
It is an XRi EFI 200 circa 1992. No electric fuel pump. Eggbeater..... I know what you are saying when you talk about hearing the fuel pump turn on when the key is in the auxillary position. That is exactly how my Daytona is set up. Again, no electric fuel pump on this motor.

I am going to start by replacing the fuel lines and bulb. I will fire it on the hose and check for leaks. If the bulb is full after 3-4 pumps, that might be an indicator the problem is solved. If I still have the same problems after the water test, I will look at an electric fuel pump.

BTW....the tanks are vented through the fill caps. That shouldn't be the issue.

Motion..... when you talk about the right front side of the engine, your talking about the passenger side of the boat I assume. Where is the low pressure diaphram pump located?

Thanks all.
 

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your engine

if your engine is an xri, it is fuel injected, and must have an electric fuel pump to run, the diaphram pump only pulls from the tanks to provide fuel for the electric pump, the efi system is 39psi, the diapram pump can only produce apprx 4psi which is good for carbs only. i dont know which side of your boat is the passenger side? but, looking at the front of the engine, you first see the ecu box mounted on the front, then moving right would be the fuel cannister housing which houses the fuel pump and also acts as a fuel resivour controling the fuel level feeding the electric pump, trust me, if thats not it, its either not an xri or has been modified to house the fuel pump in the boat.
 

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Discussion Starter #14
The cowl says 2.5L XRi. The engine is definitely fuel injected (it does have an ECU box up front). To be sure that it is a 200 XRi, I probably need to run the serial number by Mercury. Boat is at the glass shop having some mistakes from the previous owner removed. :)sphss I get it back later this week and will then check out the engine for the electric fuel pump and replace the fuel lines (to start).

The electric fuel pump is either real quiet (as in I can't hear it run) or it is not working. If it is not working, I wouldn't think the engine would run at all.

HD
 

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River Rat
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I had the same engine on my Advantage, and experienced the same thing you are. Took it to my mechanic, and he finally found an inline filter that was clogged. This filter is literally INSIDE the fuel hose right near the pump. You have to remove the fuel hose to get it out. It is conical in shape and less than an inch long. He did some research on it, and determined that it only came on SOME of the 92 engines.

Try squeezing that fuel hose to see if you can feel something hard inside, and if you do, I'll bet you have the same little fricken filter that I had....

BTW, my motor since has grenaded, and I replaced it with a 225 Optimax. I love this motor......
 

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Discussion Starter #16
Thanks all. I will be replacing all fuel lines, fuel filters, and primer bulb. Last, I will check the electrical fuel pump to determine if it is working. The electric fuel pump has me confused because I have not heard it run at all in the year I have had the boat. On this engine, is that normal? Is it that quiet? I will check it out this weekend with the cowl removed.

HD
 

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Under yo mommas bed
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Listen to Motion. If your engine is any kind of fuel injection you MUST have an electric fuel pump, period! I have an XRI system and a horn motor. The XRI takes a 39lb reg and this particular horn motor takes a 56lb reg and some other horn motors take the 39ld reg. The 56 lb reg is a black color and the 39 is a gold color. Now you know the full story. BTW, none of my fuel injection motors have bulbs.:)hand
 

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Northern CA DCB Sales
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No question about it if your motor is an EFI you have a electric fuel pump and the system runs at 39 psi like Motion said. The filter Scouter is talking about is the most common problem. The filter is a small cone screen in the u shaped hose on the bottom of the vapor seperator. With todays crap fuel I have been seeing alot more high pressure pump failures than in years past also. Also do not rule out rebuilding the low pressure pump Motion talked about. This is a normal service item overlooked by many people. The rebuild kit is a part # 21-857005A 1 and cost about $20. Hope this helps.
 

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Discussion Starter #19 (Edited)
You all were right. It does have an electric fuel pump and the pump works. :)devil It is amazing how quiet the cowl makes everything on this engine. You can't hear the fuel pump unless you pull the cowl off. You could hear everything with my old Bridgeport. Of course that holley blue was pretty dang loud.

I removed the cone filter in the U Shaped hose at the bottom of the vapor separator. I replaced the primer bulb which appeard to be fine (only flowed one way). I also replaced in-line purolator filters located about 10" from each tank. Do I need these?

I might as well rebuild the low pressure pump. I have attached a picture of the port side of the engine (bottom cut off due to my crack camera skills). Where is the low pressure pump? Also, which component is the high pressure pump.

Thanks all.
 

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Under yo mommas bed
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Yes, you need the inline filters. I believe they are 40 microns.
 
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