CONTINUOUSWAVE

I need a replacement gasoline hose assembly for my 1988 Montauk with the original 1988 Johnson 90 engine and the original 12-gallon metal tanks.

Q1: What size [rubber hose] do I need?

Q2: Where is the best place to order [a replacement gasoline hose assembly]?

Q3: Are there any complications to replace [a gasoline hose assembly between on-deck fuel tanks and the engine]?

In 1988 a Boston Whaler MONTAUK 17 would not have been delivered from the factory with an engine installed. The selling dealer would have installed the engine and done the rigging, including the fuel lines. There is not a standard Boston Whaler part that satisfies all possible arrangements of fuel tanks and engines that could have been rigged

Generally on a MONTAUK 17 the metal on-deck fuel tanks would have been two 6-gallons fuel tanks. The dealer selling the boat would have rigged the fuel tanks.

You give little information on how the fuel hose assembly is constructed.

Q4: At the fuel tank end of the "hose assembly" is there a quick-disconnect fuel hose fitting?

Q5: At the engine end of the "hose assembly" is there a quick-disconnect fuel hose fitting?

Q6: Does the path of the "hose assembly" from tank to engine remain above deck on your boat?

Q7: Does the path of the "hose assembly" from tank to engine run under the deck using the rigging tunnel?

I presume that the "hose assembly" will also contain an in-line primer bulb. If there isn't one, there should be.

Assuming there are quick disconnects at each end, you may be able to re-use the existing fittings if you examine them closely and find they are in excellent condition. If there are fittings and they need replacement, you need to find the appropriate replacement connectors for the tank or tanks and the engine.

The rubber fuel hose should conform to U.S. Coast Guard regulations. It should be marked with an identifier as "A1-15", with the date of manufacturer, and a declaration that the rubber hose is resistant degradation due to use of alcohol-gasoline blended fuels. There may also be more recent federal laws requiring compliance with permeability of the rubber.

For a good summary of the regulations that cover gasoline fuel hoses on boats, see

https://newboatbuilders.com/pages/fuel.html

As a recreational boater with an existing boat and fuel system, you are not subject to compliance with all of the regulations, but it would completely insane to ignore them and do otherwise.

I recommend you buy a new primer bulb, that you install the primer bulb so that its arrow indicating flow direction points skyward, and that the primer bulb be installed within a foot or two of the engine.

I recommend you use an OEM primer bulb. Contact you local Evinrude or Johnson dealer. Can sell you an OEM primer bulb. They can also sell you certified rubber gasoline fuel hose.

In order to assembly all of these components you will need to use the proper clamps. AVOID USING JUBILESS CLAMPS or WORN-GEAR STRAPS. The best clamps are Oetiker clamps. Nylon one-way compression clamps are also useful.

Kend wrote:Q1: What size [rubber hose] do I need?

The inside diameter of the fuel hose should meet the recommendations of the engine manufacturer. Check the operating guide for your engine to see what is recommended. If there is any doubt, use 3/8-inch ID fuel hose. The larger and heaver hose will be more resistant to damage.

The simplest method to construct a suitable replacement "hose assembly" will be to bring the existing hose assembly to your local Evinrude or Johnson dealer. Ask him to duplicate the assembly, but require that the primer bulb be located at the engine end of the hose. This method will ensure that the primer bulb won't end up buried in the rigging tunnel if you buy some pre-assembly hose and primer bulb kit.

The tanks are 12-gallon metal factory-supplied, the hose has quick connects on each end, and the hose goes below the deck through the tunnel and connects to the motor. The primer bulb is just outside the tunnel in the middle of the tanks under the seat.

I was assuming a fuel line kit that fits a Johnson motor where the hose is 3/8-inch and line 7-feet long would fit but wanted to make sure before I ordered one that is available on Amazon.

I would not order hose and primer via Amazon, but rather through an on-line marine retailer.

For alcohol resistant hose I suggest using

https://www.defender.com/product.jsp?id=4009639

and an OEM primer bulb. Use stainless steel clamps on your tank fitting, primer bulb, engine end.

Primer - OEM
https://www.crowleymarine.com/parts/755414.cfm

Ordering the items seperately allows you to place the primer bulb where you want it. Use the old hose assembly for the length.

Kend wrote:The tanks are 12-gallon metal factory-supplied...

I am sure some factory made those metal fuel tanks, but I am not quite sure that Boston Whaler provided them. In the 1988 catalogue I find a listing for a 6-gallon on-deck metal tank as an accessory, with an accessory fuel tank mat to go under the tank, and there are many prior citations of twin 6-gallon fuel tanks fitting under the reversible pilot seat in a MONTAUK.

The illustration of shows "6 GALLON FUEL TANK G5-9056-00" and includes the fuel hose and primer bulb. The illustration also clearly shows that the primer bulb is located at the engine-end of those.

But that's neither here nor there; if you can adapt a new hose and primer bulb to the existing fittings, you need not worry about finding new fittings to match the ones on the "factory" tanks.

If you buy a pre-fabricated hose the primer bulb position will be already determined. If the primer is located properly, it should be much closer to the end of the hose in the direction that the flow arrow points.