Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

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tomolalla
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Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby tomolalla » Wed Jun 08, 2022 12:32 pm

I purchased the white 22-gallon on- deck Moeller fuel tank (031626) for my 2014 Montauk 170 with the same year Mercury 90-HP engine. I recently purchased this boat and now realize it was not rigged with a primer bulb.

Q1: Does this tank need a primer bulb inline to the engine?

So far the two 6-gallon tanks are working well without a primer bulb but [I am] not sure [the engine can self-prime from] this larger 22-gallon tank.

Q2: can the existing anchors for the 6-gallon on-deck fuel tank be used for the 22-gallon fuel tank?

It looks they may work if repositioned and longer straps are used.

I have the permanent hold down kit on order but now see that it will be hard to install the pair on the bow side due to the fiberglass seat.

Q3: if I seal all the connections with double clamps and use some sealing compound do I still need to pressure test the tank as Moeller recommends?

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Phil T
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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby Phil T » Wed Jun 08, 2022 2:25 pm

Typically an inline primer bulb is installed.

There is a brass 1/4" NPT fitting that connects the tank to the hose needs to have yellow teflon tape (gas rated) on the threads.

A single stainless hose, Oetiker, pinch or snap clamp will work.

A pressure test is not necessary.
1992 Outrage 17
2019 E-TEC 90
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tomolalla
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Re: Fuel Hose Path: Width of Rigging Tunnel

Postby tomolalla » Wed Jun 08, 2022 2:42 pm

It looks like I'll need to relocate where the fuel hose emerges from below deck under the seat.

If there is away around drilling a hole, let me know.

Q4: If I do drill a new hole a few inches to the starboard, how much leeway do I have before I run out of room in the rigging tunnel?

I hate drilling holes but this looks to be a necessity to have the tank fit tight up against the forward end of the seat.

jimh
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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby jimh » Thu Sep 01, 2022 9:52 am

Using a tape sealer on threaded fuel system joints is not recommended. The tape may shred and debris could enter the fuel system. This is particularly true for on-deck tanks where there is no downstream large canister type fuel filter. Tape may work, put the installation of the tape must be carefully done.

A paste sealant is preferred for that reason. For recommended sealants see

How to properly seal fuel fittings and fuel Lines
https://support.jamestowndistributors.c ... fuel-Lines

jimh
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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby jimh » Thu Sep 01, 2022 9:57 am

Modern engines with electrically-operated fuel pumps may not need the traditional in-line primer bulb.

If you do install a primer bulb, follow the advice given in

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

More advice on fuel tanks can be found at

On-deck Fuel Tanks
https://continuouswave.com/whaler/refer ... lTank.html

Straps are usually run through a Footman’s Loop fitting, sized for the width of the strap. For more about these see

MONTAUK 17 Fuel Tank Tiedowns
https://continuouswave.com/forum/viewtopic.php?t=4484

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Phil T
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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby Phil T » Thu Sep 01, 2022 9:58 am

I have been using gas-rated teflon tape for over a decade on 3 boats without a single concern.

I respectfully disagree with Jim.

Ensuring proper paste coverage is an added chore.
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jimh
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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby jimh » Thu Sep 01, 2022 9:59 am

Do not use worm gear clamps on rubber fuel hoses. Use Oetiker clamps or nylon ratchet clamps.

Oetiker Clamps
https://www.oetiker.com/en-us/

Nylon ratchet hose clamps
https://www.freshwatersystems.com/produ ... o-0-776-od

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Re: Primer Bulb, Fuel Tank Hold Down, Fuel System Testing

Postby jimh » Thu Sep 01, 2022 10:00 am

Phil T wrote:I have been using gas-rated teflon tape for over a decade on three boats without a single concern
Yes, but you are a skilled and careful installer.

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Re: Fuel Hose Path: Width of Rigging Tunnel

Postby jimh » Thu Sep 01, 2022 11:24 am

tomolalla wrote:Q4: If I do drill a new hole a few inches to the starboard, how much leeway do I have before I run out of room in the rigging tunnel?
You are in the best position to assess the width of the rigging tunnel. I would expect you could visually gauge the width from the access under the console or at the transom. Or, insert a small stiff wire (from a coat hanger perhaps) into the existing fuel hose deck opening and feel for the walls of the rigging tunnel.

I don’t think drilling a new hole far off center should be necessary. The width of the rigging tunnel is probably only three inches. An off-center hole would also look oddly placed.