Fuel pump question

[Olias]

I was reading in another thread about someone who was having similar problems/symptoms that I'm having with my motor (see my signature) and wanted some clarification if possible. On the back of my fuel pump there is a hole that lines up with and goes directly to the #1 cylinder. I had assumed that gas was supposed to pass through there (for what ever reason). I'm learning more about this motor and fuel pump now and if I have it right there is a rubber diaphragm in the back part of the fuel pump and I guess the pressure from the cylinder is what works/opens & closes the diaphragm. Is this the case? if so, is it true that gas should not pass through that hole into the cylinder? Because mine does and I'm thinking this is what is flooding out my motor as well as causing occasional backfire. The motor will only run for a minute or so and then is impossible to start unless it sits for a while. Does all this sound about right? Someone on the other guys thread said to test the fuel pump just leave the fuel lines attached and squeeze the primer ball and if fuel comes out of that hole then the pump is bad (diaphragm is shot). That's what happens on mine now. If that's the case I'm not sure if there is a newer fuel pump that Sierra or Teleflex makes because there are no repair kits for my fuel pump. :blue: Any advice/input would be greatly appreciated. BTW...the fuel pump in the picture is not my actual fuel pump. Just a pic of my exact model for reference. Thanks.

-B-

 

[boobie]

Re: Fuel pump question

Sounds like a bad fuel pump and a model # would also help.

 

[Daviet]

Re: Fuel pump question

You are correct, the pump is actuated by pressure from the cylinder. There should not be gas coming out of the hole that mates to the block. If there is, it will cause the cylinder to run rich and flood.
If you go to marineengine.com, they will have a parts breakdown for your engine, you can find part numbers for a pump or repair parts for your engine.

 

[Olias]

Re: Fuel pump question

Thanks for the feedback. I did go to MarineEngine.Com and it's kind of weird as there is no ONE single number for the entire pump. They just list about 4 or 5 of the main parts all as being replaced by an OMC fuel pump. This one: https://www.marineengine.com/newparts/part_details.php?pnum=OMC0388685&ptype=&Engine=&Model=. I was just trying to find a comparable that Sierra or Teleflex makes that wasn't quite as expensive. Anyway, no matter.....I mainly just wanted some confirmation that mine was malfunctioning and it sounds like it is. Thanks guys.

-B-

 

[jonbellamy]

Re: Fuel pump question

That's exactly what was happening to my '68 Fastwin. I replaced mine with the Sierra 18-7351 and it runs like a charm now after adjusting the slow speed and high speed needles. I'm not sure what pump you need (they didn't make a repair kit for my stock fuel pump). I think you might need the Sierra 18-7350 (6-15hp rating) which is $44 here on Iboats. Someone please correct me if i'm wrong.

 

[Randy000]

Re: Fuel pump question

If there is fuel coming out of the pulse line the diaphragm has a hole in it. That shouldnt flood your engine, it should starve it and youll get a flat primer bulb. There are kits available for $145 for ALL the VOR pumps. There is a website, I'm not on my computer but Ill search in a minute.

Ive read in many places people claim the pump doesnt last to long after a rebuild for some reason.. I dont really buy that but I just changed my whole pump..my diaphragms were fine, the housing was leaking somewhere. The new pumps are supposed to be Ethanol resistant too.

 

[Randy000]

Re: Fuel pump question

These people have all kinds of stuff including the kits. JOHNSON EVINRUDE FUEL AND VRO PUMPS and REPAIR KITS. REPAIR YOUR VRO OR FUEL PUMP! -- MASTERTECH MARINE . Found them on yahoo search.

 

[Olias]

Re: Fuel pump question

Wow, thanks Randy. I'll check that site out. BTW...what does VRO stand for? I don't believe mine is a VRO.

-B-

 

[jonbellamy]

Re: Fuel pump question

Olias, if your motor is the 1960 10hp that is in your signature than I don't believe you'd have a VRO fuel pump (don't think they were introduced until the 90's). The VRO mixes the oil and fuel together before the carburetor (or so i believe).

 

[Olias]

Re: Fuel pump question

You are correct on both counts as it is indeed a 1960 10hp Sportwin and I do in fact have to mix the gas/oil. Thanks for that verification.

-B-