1973 Gulfstar 36 trawler fuel level

This may have been covered before but I couldn’t locate it. Can Anyone with a Gulfstar 36 trawler give me a little help. I am new to the boat and looking to find away to know how much fuel is in the tanks since obviously they didn’t come with a gauge. In the galley there is an access in the floor that has what appears to be some sort of access cap. It looks to be about 1 1/2 inch or so. I don’t want to open it without knowing what it is. Is it the fuel tank or something else ?? I know the tank is in the keel section and is glassed into the boat. And all the hoses and connections are just inside the access door under the galley steps.

Fuel level

Did you ever get the info you needed? I am in the same predicament. Bigger question that I have: How many gallons of fuel will my 1972 36' Gulfstar hold? I want to add fuel stabilizer for winter storage and have no idea of how much.

Yamahajer said:

Did you ever get the info you needed? I am in the same predicament. Bigger question that I have: How many gallons of fuel will my 1972 36' Gulfstar hold? I want to add fuel stabilizer for winter storage and have no idea of how much.

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The info I have lists your boat as 250 gallons total

PierreR, what is the source for that info. I have, from various sources, gotten numbers from 100 gal. to 250 gal. Were there various tank configurations/sizes available in that boat?

Yamahajer said:

PierreR, what is the source for that info. I have, from various sources, gotten numbers from 100 gal. to 250 gal. Were there various tank configurations/sizes available in that boat?

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If you can get access your tanks and measure to get dimensions, you can calculate the volume

Didn't those boats have integral FG tanks? If so it's probably hard to estimate, and could have varied through the production cycle.

tank capacity

Yes, the fuel tank is fiberglass and is built into the keel of the boat, below the galley floor. I'm pretty good with geometry, but given the location and shape of the tank, I don't think measuring is possible. I was just hoping someone else with a '72 36' Gulfstar, or a prior owner, might have the info I need.

jedmondson848 said:

This may have been covered before but I couldn’t locate it. Can Anyone with a Gulfstar 36 trawler give me a little help. I am new to the boat and looking to find away to know how much fuel is in the tanks since obviously they didn’t come with a gauge. In the galley there is an access in the floor that has what appears to be some sort of access cap. It looks to be about 1 1/2 inch or so. I don’t want to open it without knowing what it is. Is it the fuel tank or something else ?? I know the tank is in the keel section and is glassed into the boat. And all the hoses and connections are just inside the access door under the galley steps.

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This is a list exactly made by an german official of my fuel tank GS36mark1 trawler 1974
Succes

Apparently all the 1972 36' Gulfstars may not have the same fuel tank configuration. I helped a friend change oil on his twin engine version this weekend and his tank is just forward of his engines, with an access cap to do a "stick" measurement of fuel level, accessed via the panel under the steps to the galley. The access panel in his galley floor goes to his water tank. My single engine version has the water tanks under the back bunks (may be a retrofit) and I do not have the cap to do a fuel measurement like his. I now use an electrician's "snake" (used to pull wire), inserted through the deck fuel fill fitting, to get an approximate fuel level. Not extremely accurate, but with a 250 gallon capacity, close is good enough.

jedmondson848 said:

This may have been covered before but I couldn’t locate it. Can Anyone with a Gulfstar 36 trawler give me a little help. I am new to the boat and looking to find away to know how much fuel is in the tanks since obviously they didn’t come with a gauge. In the galley there is an access in the floor that has what appears to be some sort of access cap. It looks to be about 1 1/2 inch or so. I don’t want to open it without knowing what it is. Is it the fuel tank or something else ?? I know the tank is in the keel section and is glassed into the boat. And all the hoses and connections are just inside the access door under the galley steps.

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I recently purchased a 1980 Gufstar 44 Motor Cruiser that has a similar configuration, but a larger tank that is accessed in the engine room. Your tank should have something like a 1.5-in bronze dust cap that covers a smaller 1.0-in threaded fitting. It seems like the cap is used to hand-tighten/loosen the plug for the inspection port. Originally, there should have been a metal Tee-tool that looks like an old-fashioned folding ruler that has marks for every 25 gallons of fuel. You unfold and drop the tool into the inspection port and measure the level like a dip stick on an engine. I had an older Pacemaker 33 aft cabin that only had a wooden rod to make the same kind of measurement. The problem on the GS is that the tank follows the Vee of the hull, so measurements will not be linear. I recall seeing a post somewhere else where someone bought a boat, saw the tool, didn't recognize what it was for, and tossed it! If you can find someone with the tool, hopefully they can give you the measurements vs. tank volume.