Fuel tank/pickup question

seef158
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Fuel tank/pickup question

Postby seef158 » Tue Aug 14, 2018 9:07 pm

A few questions on fuel tank and pickup, first some background. I've been troubleshooting runability issues on my new to me 28 express with single 318. I've got it running reliably after fixing numerous issues, carb, timing, comdenser, wiring and a weak coil among some other things. Once I had it running well I found that it will run out of fuel above 2500 rpm. I pulled the fuel pick up out and the bottom of the copper pipe that sucks up the fuel was literally corroded away so badly that it was all sucked/caved in on itself and looked like Swiss cheese for all the small holes in it. It fell apart as soon as I touched it. There in lies the first question....

How far from the bottom of the tank should this tube be? I measured the tank and made up a new pickup pipe and left about 1/4 inch gap between the pipe and bottom of tank, at least that's what my measurement tells me.

Second question.... is there a good way to clean out the steel tank or should I just replace? I am getting constant rust out of the tank and it will actually plug the pick up at times. Since replacing the fuel pick up I can pull 3600 rpm and still be slowly gaining speed/rpm but it will still run out of fuel eventually. When I back out of the throttle it will stay running and if I blow back through the line there is a lot of resistance at first. Between that and the amount of crud in my rock catcher fuel filter I figure my pickup tube is just plugging up.

3rd question. Anyone replaced the tank on a 28 express? I'm looking for as close to plug and play as possible, and it appears I could get the old tank out through the rear deck hatch. If that's the case I would like to find something very similar in dimension so I could replace without pulling the deck up. Mine is the round steel tank, 65 gallon I believe.

Thanks in advance for any and all help.
1972 28' express single 318, working on getting the bugs worked out.
forest lake, mn
Duluth, mn
Washburn, wi

jralbert
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Re: Fuel tank/pickup question

Postby jralbert » Tue Aug 14, 2018 9:16 pm

also take a look at the fuel filter at the mouth of the carb. That is, where the fuel line enters the carb
-joel-
former owner 1988 '32 FB Sedan
Chesapeake Bay
twin 318 / 240 hp
Potomac MD

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Busia
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Re: Fuel tank/pickup question

Postby Busia » Tue Aug 14, 2018 11:11 pm

On my 32 I had a new aluminum tank welded up. You might measure your hatch and figure the maximum size that will fit. I would look at a fuel tank from a semi-tractor. Lots of them out there and you might find one cheap.
BUSIA
located in Ketchikan, Alaska. Gods country
32 foot Marinette express. (no fly bridge)
twin 350 Crusader (Chev 350) engines
1:1 Borg Warner velvet drive transmissions
Closed cooling (antifreeze in the engine)
Proud to be retired IBEW

seef158
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Re: Fuel tank/pickup question

Postby seef158 » Wed Aug 15, 2018 6:06 am

Thanks for replies guys. Screen filter at mouth of carb is clean, just had it rebuilt and double checked the screen again.

Would a tank from a semi be coast guard legal? I wondered about one and if insurance could deny a claim if there were ever an issue...?
1972 28' express single 318, working on getting the bugs worked out.
forest lake, mn
Duluth, mn
Washburn, wi

MetalHead
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Re: Fuel tank/pickup question

Postby MetalHead » Wed Aug 15, 2018 6:16 am

I know the sender should be 1 inch from the bottom, so I think in our boats below that should work. 1/2 to 3/4 inch. Further off the bottom means less chance to pickup crud. You should check around on getting another tank. You may be able to find someone dismantling a M that has a tank they would see cheap. I would want aluminum and certainly make sure it is in good shape, or just bite the bullet and have one made to fit.
1959 Family Cruiser - Sold - Gary Dick - 12/05/14
1963 Express 31x10 - Sold - Joe & Ginger Tabor - 01/21/2017
1963 Express 31x8.5 - In Dry Dock - Restore Underway
1987 Sportsman - On Rolling Slip - Ready To Go !!!
Big BigM 's Rule !!!
Columbiana, AL

MetalHead
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Re: Fuel tank/pickup question

Postby MetalHead » Wed Aug 15, 2018 6:18 am

Also make sure all your lines from the tank are new and the correct size. It could be that you have a diameter hose that is to small to keep up with the fuel pump. Is your pump electric or mechanical?
1959 Family Cruiser - Sold - Gary Dick - 12/05/14
1963 Express 31x10 - Sold - Joe & Ginger Tabor - 01/21/2017
1963 Express 31x8.5 - In Dry Dock - Restore Underway
1987 Sportsman - On Rolling Slip - Ready To Go !!!
Big BigM 's Rule !!!
Columbiana, AL

meltonhill
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Re: Fuel tank/pickup question

Postby meltonhill » Wed Aug 15, 2018 3:24 pm

Seef158 tractor trailer tank isn't uscg approved but it won't fit. I tried.

seef158
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Re: Fuel tank/pickup question

Postby seef158 » Wed Aug 15, 2018 8:25 pm

MetalHead wrote:Also make sure all your lines from the tank are new and the correct size. It could be that you have a diameter hose that is to small to keep up with the fuel pump. Is your pump electric or mechanical?


A fair amount of the line is still the original copper, there is a small amount of rubber line to plumb in the rock catcher and fuel/water separator and a stainless line from pump to carb. The rubber line is 5/16 and I think the stainless is 3/8, which seems like it should be plenty big? Am I thinking correct here? I want to say that the fuel line I'm my 454 in my 24' formula years ago was 5/16 and thankfully I know from experience this 318 requires far less fuel than that BBC did!
1972 28' express single 318, working on getting the bugs worked out.
forest lake, mn
Duluth, mn
Washburn, wi

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bcassedy
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Re: Fuel tank/pickup question

Postby bcassedy » Thu Aug 16, 2018 7:33 am

seef158 wrote:
MetalHead wrote:... I know from experience this 318 requires far less fuel than that BBC did!


:D Good point!!!

My 32' SB also has 5/16" from the tank up to where the fuel shutoff valves (including the distribution manifold & Perko fuel/water separator) are located (toward the front of the engine. From there it's a short run of marine grade rubber (MGR) fuel hose to the fuel/water separator canister fitting, a stub run of MGR to the Floscan meter, and then to the electric fuel pump. From the output of the fuel pump it's again 5/16" copper line to the inlet side of a steel fuel filter and again from the outlet side of the fuel filter up to the carb.

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

seef158
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Re: Fuel tank/pickup question

Postby seef158 » Thu Aug 16, 2018 1:08 pm

Thanks for verifying Bill. I've got the owner of my old 28 looking at the aluminum tank in his boat to see if he can get me some data, then I could order a tank I know will slide right into place.
1972 28' express single 318, working on getting the bugs worked out.
forest lake, mn
Duluth, mn
Washburn, wi