I think I am having fuel issues but not sure what the cause is.

[tcfarmer]

I own a 1985 Evinrude 115 with VRO. I recently took apart the fuel/oil pump to investigate my lack of fuel to the carbs. When I took apart the pump I noticed the small black rubber ring was concave and not flush against the plastic piece behind it. So I flipped it over and BOOM! I cranked it and I had fuel come out the top of the pump. Currently my only issue is when I am on the lake it Idles and runs perfect but when I jump on it full throttle it runs just long enough to get on a plane and just start to get cookin then it starts acting like I am out of gas. I had 2 thoughts on this either there was some kind of restriction in the brand new fuel line or in the tank so I removed the fuel gauge sending unit and dropped the hose directly into the tank and ran it on the trailer and with in 1-2 minutes it started coughing and then it died. If I let off the throttle and run at 3000rpms I can cruise all day but as soon as I go wide open it nosedives. I noticed on the fuel pump it looks like the diaphragm is adjustable to I put a couple turns on it to try to get a longer throw on the diaphragm and it didn?t make any difference. If any one has any thoughts I would surely appreciate them as I am at my wits end and I cannot afford a new fuel pump assy, at least not for a while. I was looking online and saw a rebuild kit I wonder if thats what I need?

 

[crb478]

Re: I think I am having fuel issues but not sure what the cause is.

I own a 1985 Evinrude 115 with VRO. I recently took apart the fuel/oil pump to investigate my lack of fuel to the carbs. When I took apart the pump I noticed the small black rubber ring was concave and not flush against the plastic piece behind it. So I flipped it over and BOOM! I cranked it and I had fuel come out the top of the pump. Currently my only issue is when I am on the lake it Idles and runs perfect but when I jump on it full throttle it runs just long enough to get on a plane and just start to get cookin then it starts acting like I am out of gas. I had 2 thoughts on this either there was some kind of restriction in the brand new fuel line or in the tank so I removed the fuel gauge sending unit and dropped the hose directly into the tank and ran it on the trailer and with in 1-2 minutes it started coughing and then it died. If I let off the throttle and run at 3000rpms I can cruise all day but as soon as I go wide open it nosedives. I noticed on the fuel pump it looks like the diaphragm is adjustable to I put a couple turns on it to try to get a longer throw on the diaphragm and it didn?t make any difference. If any one has any thoughts I would surely appreciate them as I am at my wits end and I cannot afford a new fuel pump assy, at least not for a while. I was looking online and saw a rebuild kit I wonder if thats what I need?

I think that a rebuild kit is the next logical step. Flipping the diaphram over does not turn it from a weak diaphram into a strong one

 

[tashasdaddy]

Re: I think I am having fuel issues but not sure what the cause is.

agree, or a new pump and be sure.

 

[tcfarmer]

Re: I think I am having fuel issues but not sure what the cause is.

Anyone know the specs for the fuel pump? Like What PSI should it be at?
And is there a certain GPH it should pump? I am thinking of just wiring in a electric fuel pump . I could do away with the primer bulb and just power it with the ignition circuit so it cuts off when the key is turned off . I found a universal one for 45$ but I need to know the specs. Here are my options.

1. 12-volt Electric Fuel Pump, 1-1/2 to 3-1/2 psi, 25 GPH Delivery Capacity

2. 12-volt Electric Fuel Pump, 2-1/2 to 4-1/2 psi, 30 GPH Delivery Capacity

3. 12-volt Electric Fuel Pump, 4-1/2 to 6 psi, 35 GPH Delivery Capacity

4. 12-volt Electric Fuel Pump, 7 to 9 psi, 45 GPH Delivery Capacity

 

[iwombat]

Re: I think I am having fuel issues but not sure what the cause is.

Why put in yet another component? Fix the pump you got with a rebuild kit. I think if you go the electric pump route you'll need to start pre-mixing as well.

 

[tcfarmer]

Re: I think I am having fuel issues but not sure what the cause is.

I think there might be a crack in the housing near the bolts, it might be sucking air too. I took it to the lake last night and ran it on the trailer. If I pumped the bulb it would run all day but if I stopped it took about 10 seconds under full throttle for it to die.

 

[tcfarmer]

Re: I think I am having fuel issues but not sure what the cause is.

Well I guess no one knows the answers to my questions. So I went ahead and purchased and installed the Mr. Gasket #42S. I am off to the lake tomorrow night to test it out. It ran like a champ at home on the muff. With no leaks with the motor off and the key on. Eventually I plan to replace all the dang zip ties with hose clamps. For an even more worry free day at the lake. Here is the info on the Fuel Pump for anyone interested.
BTW, does anyone happen to know what type of signal runs thru the Kill Switch? Currently it just runs thru the ignition switch but I would like to also have the Kill Switch stop it too God forbid I fly out of the darn thing.


Mr. Gasket's new "Micro Electronic" fuel pumps feature solid state, worry free electronics and make great stand alone or booster pumps. They are self priming and virtually eliminate vapor lock and flooding. They have a simple two wire hook-up to any 12 volt negative ground system and only require one amp draw at maximum delivery. Fittings and mounting hardware are included.
2-3.5 psi, 42 gph.
Not for fuel injection applications.