Fuel Hose and Primer Bulb

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Trainerjim
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Fuel Hose and Primer Bulb

Postby Trainerjim » Sat Jun 19, 2021 11:13 pm

Q1: Could dry rot in a fuel hose cause the fuel hose to collapse?
Q2: Could dry rot in a fuel house cause the primer bulb to collapse?
Q3: Should the primer bulb in a fuel hose be located at the fuel tank end of the hose?
Q4: Should the primer bulb in a fuel hose be located at the fuel-water separator filter end of the hose?

LONG BACK STORY:
In June 2021 we bought a 1993 Montauk in great condition that was re-powered in 2006 with an E-TEC 90. On the second outing and prior to launching, a small amount of fuel was seen on the deck behind the fuel tanks. The fuel tanks are well maintained [and are] original to the boat. The day before the fuel tanks were filled.

[The small amount of fuel seen on deck was thought to be from] a slight leak around [a tank level] gauge.

The engine was started normally. We had an uneventful trip to the sandbar. On the return trip the engine stalled after about five minutes at idle speed and one minute at 3,000 RPM.

Upon inspection, the fuel line was dry rotted and leaking next to the tank connector.

After an onboard repair, I noticed the primer bulb stayed flat when I pumped it. The only way to get it to re-inflate was to take the connector off the tank. This happened with both tanks. The bulb is next to the connector at the tank.

There is a fuel-water separator filter mounted above the sump.

After a few pumps the engine started and ran about five minutes before stalling again. This happened twice, both times with the bulb being flat. After the third stall the boat ran at 3000 RPM for about 1r minutes back to the landing.

EVEN MORE BACKSTORY:
Previously I owned a 1989 15 Super Sport.

jimh
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Re: Fuel Hose and Primer Bulb

Postby jimh » Sun Jun 20, 2021 9:00 am

For advice on how to use the fuel hose primer bulb as a diagnostic indicator, read my 17-year-old article in REFERENCE at

A Primer on Primers
https://continuouswave.com/whaler/reference/primer.html

HINT: if a primer bulb collapses after the engine has been running, the cause of primer bulb collapse is probably an obstruction or blockage in the fuel hose that it UPSTREAM of the primer bulb.

The article linked above gives advice on the best location for a primer bulb in a fuel line.

jimh
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Re: Fuel Hose and Primer Bulb

Postby jimh » Sun Jun 20, 2021 9:05 am

Regarding what might cause a rubber fuel hose to collapse, I don't exactly know what the condition "dry rot" means with regard to rubber.

A frequent problem seen in rubber fuel hoses, particularly fuel hoses that have a silvery metallic outer jacket, is for the inner liner that surrounds the passage in the hose to collapse under suction, causing an obstruction. If you have a fuel hose with a silver outer jacket, you should immediate remove those hoses and replace them with Evinrude OEM rubber fuel hose.

Any rubber hose made after c.1987 should be clearly marked with the legend "ALCOHOL RESISTANT" if the fuel hose is resistant to decay caused by use of alcohol-gasoline or ethanol-gasoline blended fuels.

Inspect the fuel hoses on your 1993 MONTAUK 17 to determine if they are marked with "ALCOHOL RESISTANT" labeling.

In the overall expense of boating a new six or eight foot section of rubber fuel hose is a trivial expense, so if there is any indication that the 28-year-old rubber fuel hose is in poor condition--which seems like a very good inference from your narrative---replace the fuel hose. immediatell. If replacing the fuel hose, replace the primer bulb. The Evinrude OEM fuel hose and OEM primer bulb are very quality parts; I recommend you buy those OEM parts from an authorized dealer.

Do not underestimate the amount of VERY EXPENSIVE DAMAGE that WILL OCCUR if you operate the E-TEC engine from a fuel supply that has a blockage and causes the E-TEC to run out of fuel and stall. Operating the very expensive fuel injectors in an E-TEC without proper lubrication and cooling from the fuel will harm the fuel injectors.

jimh
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Re: Fuel Hose and Primer Bulb

Postby jimh » Sun Jun 20, 2021 9:20 am

With regard to an E-TEC engine: the E-TEC engine has its own fuel pump. The electric fuel pump will run as soon as the ignition key switch is turned to RUN from OFF. The electric fuel pump will run until the fuel-vapor separator tank is filled. You can generally hear this pump running when the key is in RUN and the engine has not been started.

If there is an obstruction in the fuel line and no fuel is flowing to the engine, the electric fuel pump will be running dry. This condition can cause damage to the fuel pump. The fuel pump is part of the fuel-vapor separator tank. If the fuel pump is damaged, you may have to buy the entire fuel-vapor separator tank and fuel pump assembly to replace the damaged pump. This will be a very expensive repair.

One of the WORST possible conditions in which an E-TEC engine can be run is with a blockage in the fuel supply that limits or stops the flow of fuel to the engine.

Trainerjim
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Re: Fuel Hose and Primer Bulb

Postby Trainerjim » Sun Jun 20, 2021 11:17 am

Jim, thank you for the very informative replies. I plan on replacing the fuel line and doing a better inspection of the [on-deck fuel] tanks. I will look to find the OEM lines. The lines on the boat are OMC. It is probably time to replace the original metal tanks.

Jim

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Phil T
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Re: Fuel Hose and Primer Bulb

Postby Phil T » Sun Jun 20, 2021 1:54 pm

When repowering it is always wise to replace all components of the fuel system from the engine to the tank. I just did this in May.

Ensure you replace the fuel hose with a marine rated hose that is black (not grey or blue) and has "alcohol resistant" stamped on the outside.

Install a OEM bulb (BPR, Mercury, Yamaha, Suzuki et.al) and not aftermarket (Sierra etc.).
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

jimh
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Re: Fuel Hose and Primer Bulb

Postby jimh » Sun Jun 20, 2021 2:00 pm

Another source of obstruction in the fuel system is a debris in the fuel tank that has collected at the bottom of the fuel pick-up tube. Some fuel tanks incorporate a mesh screen at the fuel pick-up point; the screen could be full of debris.

Don SSDD
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Re: Fuel Hose and Primer Bulb

Postby Don SSDD » Mon Jun 21, 2021 6:46 am

For the benefit of others reading this posting, not all gray hose is questionable quality, there is some that is very good quality and has the liner imbedded in the outer skin so that it cannot delaminate.

Look for posts on here about this gray line and you’ll find pictures of the good hose and bad hose.
[Moderator's note: if you want to refer to other articles, please give the URL to those articles. Do not ask the readers to search for them.]

On my Outrage, the hoses used on the in hull aluminum fuel tank are in some tight spaces and the good gray hose is much easier to install than the black original style rubber hose, it is thinner and the outer skin is more slippery. I installed this gray hose before finding out on here there was a possible concern with delamination of the liner. Luckily, the hose I bought was the later gray hose with the correct liner.

For a Montauk, all hoses are easy to install so the original style hose will work fine.

Don
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia

jimh
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Re: Fuel Hose and Primer Bulb

Postby jimh » Mon Jun 21, 2021 8:44 am

Don SSDD wrote:For the benefit of others reading this posting, not all gray hose is questionable quality...

The occurrence of collapsed fuel hose liners in hoses with gray metallic color was extremely common while those low-quality hoses were being manufactured by aftermarket suppliers. The failures were closely associated with use of ethanol-gasoline blended fuels.

Recommendations for continued use of a fuel hose with gray color should include a specific manufacturer and model of hose.

Don SSDD
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Location: Nova Scotia

Re: Fuel Hose and Primer Bulb

Postby Don SSDD » Wed Jun 23, 2021 10:47 am

https://continuouswave.com/forum/viewto ... f=6&t=3782

The above is a discussion on CW from 2018 regarding gray hose, I have the Trident gray hose, uscg and epa rated.
1986 Outrage 18 with 2001 Honda 130 HP
Former Owner 1991 Guardian 19 with 1994 Evinrude V4 140HP
Former owner 1987 Montauk with 1998 Mercury 90HP
Nova Scotia