Fuel gauge in 1974 MT

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nodestination

Senior Member
Joined
Apr 28, 2016
Messages
199
Location
usa
Vessel Name
No Destination
Vessel Make
1972 GulfStar Trawler 36
Hello. I still have original ( to the best of my knowledge) fuel tanks in my 1974 MT 34. Not knowing of how much fuel I have, is mine most concern. Where I can find the sight glass fuel gauge?. Each tank have a plug at the bottom and I am planing to put a valve, so I can drain some water. That small stick is hard to read. Thanks.
 
I use only my hour meter. after the first yrear of owning this boat, I knew the consumption per hour, easy to look in the log for the hours at the last fill up, calculate the # of gals used, check that when fuelling. Quickly found I was always very close to bang on when filling up.

Don't need no stinkin fuel fuage!
 
There probably are no sight tubes on those tanks. Dip sticks in the fill openings is the usual way, or have gauges installed. I hope you get the tanks drained before putting valves on the bottom. And while doing that, get the tanks opened up for cleaning and inspection. Have you had the boat long? Tanks could be full of crud as well as water. Just went thru this myself on my 78 CHB. Drained, access ports installed, cleaned, fuel polished and refilled. Tank guys said my original tanks were good, at least for now, but they are still old tanks.
 
I use bare wood dip sticks. Fuel wet area is easy to see and drys before being used again. And I have old eyes. My tanks are 1942. No water in the tank, no rust or crud.
 
"That small stick is hard to read."

get a better stick.
 
Thanks for the info. My problem is, that I have no idea of how much fuel I have. The previous owners said that I should have no more that half of a tank(each), but when I try to put a fuel in, I only out 7 gallons and overflow. No way for me to get all the fuel out. Does any one know the size of the plug on the bottom of a tank?. I may have to do a quick switch ( plug for valve).
 
Call a tank repair or fuel polishing firm and have them come pump the fuel out. Do not attempt to make a quick switch on the bottom of the tank. You could wind up with all your fuel in the bilge.
 
Few years ago, I do not know when, someone invented simple device called "oil pan". Fits good under the tank. Is the plastic "thing" that you catch a oil when you drain a engine. I need to know the size of the plug, so I know what valve to buy. I do not think, that the fuel polishing company know the plug size.
 
"I need to know the size of the plug, so I know what valve to buy"

Go take a couple of different size plugs with you and see which matches.
 
Few years ago, I do not know when, someone invented simple device called "oil pan". Fits good under the tank. Is the plastic "thing" that you catch a oil when you drain a engine. I need to know the size of the plug, so I know what valve to buy. I do not think, that the fuel polishing company know the plug size.

You could do that. Have the valve all gooped up with rector seal or Teflon, or whatever your choice of sealer is. Have an assistant ready to hand the valve to you cause you'll need both hands to remove the plug and cover the hole.
Put a bunch of oil diapers around to catch the spray and dribble. Then screw in the valve.
Make sure you have clearance to doo all this.
I did something similar when I changed out my old autopilot. I only lost a few drops of oil.
But I was lucky in that the threads were good, I didn't fumble and I had a good assistant.
 
We are talking about a fuel tank here right? A little more risky than auto pilot oil. Sure a guy might get lucky and have your new fitting screw right in, but one time on the first oil change on a brand new truck, the plug stripped the threads on the way out! Guess what, it would NOT go back in. Not something I would attempt on a fuel tank unless I knew for certain it was almost empty. But whatever.
 
I just do not want to spend few hundreds of dollars on fuel polishing service. First will go water then fuel. Maybe I get lucky. Wooden plug may work in emergency. Can not find on internet the plug size.
 
Maybe you get lucky, maybe not. Depends on how your luck runs. My old man who had just watched a Japanese torpedo sail UNDER the keel of the fortunately shallow draft wooden ship he was on in the South Pacific during WWII told a friend, "I would rather be lucky than smart".
 
As you can see, I am not that bright. Counting on luck on my side.
 
All Marine Traders are different.
That said, look at the top of the fuel tanks by the pickups (which should be on the top). There should be a plug with a wire handle sticking out of it. This is the dip stick.

The starboard side should be easily seen and removed by picking up the cushion and plywood. There should be an access port to the dipstick.

The port side is more difficult. You need to remove the rear settee drawer and possibly the cushion and plywood. There should be a hole in the flooring to remove the dip stick.

Trying to pull a quick switcheroo under 1/2 tank of diesel is not such a good idea. MT made all their parts in Asia. US plugs may or may not fit and will definately be a tough fit. If you insist, try to create a vacuum in the tank to hold the fuel back. A Novena would be good too.
 
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