Should I have fuel shut off valves?

[seachicken]

So had some issues with my 03 225 Yamaha this weekend. Would not rev much past 3000 rpm and bog down after idling for a while. Kicker runs fine. I noticed the kicker filter was leaking fuel out and air in so replaced it thinking that was the issue (fuel looks different in bowel because I filled it from a little gas can). Filter was dirty and (so horribly tight I think it might have had issues before), honestly think the PO put used filter assemblies on without new elements. Still have an issue though, if we pump the bulb for the main it gets it going and runs fine up to 4000 rpm cruise. I'm going to replace the main filter, pump ball, fuel lines, engine fuel filter etc. There is a shutoff on the inlet to the main filter, should the be one on the kicker filter? Is it normal (or required ) to have fuel shutoff valves? My yacht buddy thinks they should be before the pumper balls. What the general consensus? Also should I be looking at the engine fuel pump?

 

[wolf]

Im pretty sure you want the primber bulbs after the filters and yes fuel shut offs for sure, thats a very weird configuration ....

 

[ship happens]

With modern fuel injected marine engines, the primer bulbs become a tool for diagnostics and servicing the filters. They need to be between the tank and the filter. Closest to the tank for best results. Bulbs or any pumps for that matter want to push fluid not pull fluid. Fuel shutoffs are not required. However in some instances they do serve a purpose.

Those racor filter heads you have are a pain in the butt when installing into a boat with outboards and more than one engine. They were really designed for Inboard engines. That's why they have 2 inlets and only one outlet. If it were me I would get a new filter head with 2 outputs and make things alot simpler

 

[Sharphooks]

I’m big on fuel shut off valves, especially when my fuel water separators stack up with water (crappy boat design—-filler caps are flush with the deck in a low spot that collects rain water)

The shut off valves are not necessary to drain the water out of the see-through plastic bowl but they’re nice to have if you need to change out the entire filter which I was forced to do on the fly this summer due to not only water but foreign materialI I saw stacked up in the plastic bowl

 

[wolf]

With modern fuel injected marine engines, the primer bulbs become a tool for diagnostics and servicing the filters. They need to be between the tank and the filter.

Wow I stand corrected so answer me this then how come the bulb is like 24 inches from the connecton to my kicker??asking for a freind LOL and the marine shop has my bulb after the filter on my main????
now im really confused.....

 

[ship happens]

Wow I stand corrected so answer me this then how come the bulb is like 24 inches from the connecton to my kicker??asking for a freind LOL and the marine shop has my bulb after the filter on my main????
now im really confused.....

Just because a shop installed it that way definetly doesn't mean it's done correctly. Putting primer bulbs on fuel lines going into the engine were for old carburated engines. With injection, there is alot of fuel onboard the powerhead once the engine is installed and primed. Between the VST and the injection rails and lines there is alot of fuel stored there. The fuel that's stored inside the VST is all ready to go once you turn the key. So in injection there is no need for a primer bulb. Only when you install a new engine, so you can prime the VST. If your kicker is carburated then yes you can put a bulb there, however putting the bulb between the tank and the filter works better, because now you have the ultimate tool for servicing and diagnostics for future incase something malfunctions.

If you change your filter, or have any kind of fuel issues, it's nice to ba able to pump by hand and fill up the filter with ease. It's near impossible to do that with the bulb after the filter. Pumps don't have much priming capability. They can push fluid a mile however they can only prime several feet. Putting a gigantic air space in between a primer bulb just makes it impossible to prime.

Not only does it physically make sense, and serves as a multi purpose tool, it also allows for cleaner rigging installations.

 

[InterMechanico]

Wow I stand corrected so answer me this then how come the bulb is like 24 inches from the connecton to my kicker??asking for a freind LOL and the marine shop has my bulb after the filter on my main????
now im really confused.....

Ok here goes…
Hydraulics!

A positive displacement pump, be it a manual bulb, plunger and check valves, external gear, internal gear, vane or piston does not pump anything. All it is able to do is move fluid from the inlet to the outlet. In doing so, it reduces the pressure at the inlet which encourages fluid to fill that space. Atmospheric pressure at sea level is 14.7 psi. That pressure acts equally on all surfaces, including the surface of the fuel in your tank. This is called head pressure.

When you add something like a bulb pump with a check valve introduces a pressure drop into the circuit, you reduce the head pressure by that pressure drop.

Any pressure drop on the inlet side of a pump is undesirable. Necessary in some cases, but undesirable nonetheless.

Assuming that the “pump” in this case is at the Engine inlet, the effect of the placement of the various pressure drops will not change the overall drop in head pressure to the pump.

From a reliability standpoint, I could see a case for placing the bulb primer after the filter head would more easily identify an air ingress issue at the filter head, perhaps due to an improperly seated filter or bowl during a service, potentially preventing a more inconvenient problem from occurring later.

From a convenience standpoint, placing the primer ahead of the filter reduces the effort required to prime the system.

 

[InterMechanico]

Just because a shop installed it that way definetly doesn't mean it's done correctly. Putting primer bulbs on fuel lines going into the engine were for old carburated engines. With injection, there is alot of fuel onboard the powerhead once the engine is installed and primed. Between the VST and the injection rails and lines there is alot of fuel stored there. The fuel that's stored inside the VST is all ready to go once you turn the key. So in injection there is no need for a primer bulb. Only when you install a new engine, so you can prime the VST. If your kicker is carburated then yes you can put a bulb there, however putting the bulb between the tank and the filter works better, because now you have the ultimate tool for servicing and diagnostics for future incase something malfunctions.

If you change your filter, or have any kind of fuel issues, it's nice to ba able to pump by hand and fill up the filter with ease. It's near impossible to do that with the bulb after the filter. Pumps don't have much priming capability. They can push fluid a mile however they can only prime several feet. Putting a gigantic air space in between a primer bulb just makes it impossible to prime.

Not only does it physically make sense, and serves as a multi purpose tool, it also allows for cleaner rigging installations.

This is great

 

[seachicken]

Ok thanks, this is all making sense, I do like the idea of the primer bulb under the filters, where should shutoff valves be though? I'd rather not loose the prime when changing filters or to isolate one engine if there is an issue so they make sense to me.

I have some spare filters so will run this configuration for now but will look at getting a new filter head with dual outputs.

I will stop by the Harbour Chandler tomorrow and see what they have and go ahead with the fuel lines, fittings and filters.

 

[ship happens]

Ok thanks, this is all making sense, I do like the idea of the primer bulb under the filters, where should shutoff valves be though? I'd rather not loose the prime when changing filters or to isolate one engine if there is an issue so they make sense to me.

I have some spare filters so will run this configuration for now but will look at getting a new filter head with dual outputs.

I will stop by the Harbour Chandler tomorrow and see what they have and go ahead with the fuel lines, fittings and filters.

Honestly go to greenline or a hose and fitting outlet. Get proper fuel line. The parker stuff is the best. Has a red stripe on it.

Shutoff valves can certainly be a handy edition to a multiple engine configuration. You can get aluminum valves that have MPT on one end, and hose barb on the other. That way its easy and slim and your not mixing metals which in my opinion is the most important thing there. The EVM valves like this one. Harbour chandler should be able to order some or any marine dealer.





Can put these type valves directly onto the filter head outputs.

 

[DanJ]

Ok thanks, this is all making sense, I do like the idea of the primer bulb under the filters, where should shutoff valves be though? I'd rather not loose the prime when changing filters or to isolate one engine if there is an issue so they make sense to me.

I have some spare filters so will run this configuration for now but will look at getting a new filter head with dual outputs.

I will stop by the Harbour Chandler tomorrow and see what they have and go ahead with the fuel lines, fittings and filters.

I have a couple filter heads if you need them

 

[seachicken]

Honestly go to greenline or a hose and fitting outlet. Get proper fuel line. The parker stuff is the best. Has a red stripe on it.

Shutoff valves can certainly be a handy edition to a multiple engine configuration. You can get aluminum valves that have MPT on one end, and hose barb on the other. That way its easy and slim and your not mixing metals which in my opinion is the most important thing there. The EVM valves like this one. Harbour chandler should be able to order some or any marine dealer.


View attachment 109849


Can put these type valves directly onto the filter head outputs.

Thanks Ship, I'll go to NewLine and see what they have.

 

[ship happens]

Thanks Ship, I'll go to NewLine and see what they have.

No worries. I've used newline in a pinch. They had the continental fuel line last time I was in there. Wasn't impressed. The OD of the fuel line makes it impossible for some engine boots and when using it with 90s on filter heads as well. It's got a undesirable form factor. Fyi

 

[BA48]

Try to get full port valves

 

[Rain City]

Honestly go to greenline or a hose and fitting outlet. Get proper fuel line. The parker stuff is the best. Has a red stripe on it.

Shutoff valves can certainly be a handy edition to a multiple engine configuration. You can get aluminum valves that have MPT on one end, and hose barb on the other. That way its easy and slim and your not mixing metals which in my opinion is the most important thing there. The EVM valves like this one. Harbour chandler should be able to order some or any marine dealer.


View attachment 109849


Can put these type valves directly onto the filter head outputs.

This is so satisfying

 

[seachicken]

Well I replaced the spin on fuel filter and the fuel lines, added a shutoff to the kicker, new pumper to the main. No improvement on the bogging, watching some videos and reading online I'm thinking something in the VST, can hear one of the pumps cycling, assuming the low pressure pump. I guess VST should be cleaned anyway, just want to get out to Renfrew Friday though.

 

[wolf]

Just because a shop installed it that way definetly doesn't mean it's done correctly. Putting primer bulbs on fuel lines going into the engine were for old carburated engines. With injection, there is alot of fuel onboard the powerhead once the engine is installed and primed. Between the VST and the injection rails and lines there is alot of fuel stored there. The fuel that's stored inside the VST is all ready to go once you turn the key. So in injection there is no need for a primer bulb. Only when you install a new engine, so you can prime the VST. If your kicker is carburated then yes you can put a bulb there, however putting the bulb between the tank and the filter works better, because now you have the ultimate tool for servicing and diagnostics for future incase something malfunctions.

well that helps thaks for that and i have those exact same shut offs at my tank and at my filter (that i installed)