6 hole fuel sender replacement options

[sixdeep]

I've just removed a rusted out sender from my boat. It has a 6 bolt flange. 60mm diameter and equal bolt spacing of 30mm. Tank hole is 45mm. I found a VDO adapter to run a 5 bolt flange sender but the hole for that is 54mm so its not going to work.

Anyone know if you can still get a 6 bolt sender or where i could get an adapter that would work? The current 6 bolt setup seems to have studs welded on it. Thought about maybe redrilling a 5 hole for my setup but that seems a bit sketchy

 

[skyking897]

Re: 6 hole fuel sender replacement options

I had to replace the sender in my port tank last year. After much searching for the right sender, I ended up using a universal one that matched my gauge. I had to drill new holes in the tank to make it fit. I packed the drill flutes with grease to catch any aluminium bits as well as sticking masking tape on the underside of the hole. Never got any bits in the tank this way. The new gasket covered the old holes and that alone probably would have prevented any fuel leaking but I used a product called "GOOP" to coat all over the sending unit flange and screws. It is impervious to gasoline and have not had any leaks.

 

[UncleWillie]

Re: 6 hole fuel sender replacement options

Keep in mind that fuel send bolt holes are often NOT evenly spaced.
You may need to rotate the sender until you find the matching spacing.
The offset is subtle but critical.

 

[Texasmark]

Re: 6 hole fuel sender replacement options

Why not get an aluminum piece of material of 1/8" or so of whatever diameter you choose and match drill/tap mounting holes to agree with your float flange. Rough up and degrease the underside of the alum and attach it to the tank with JB weld, or some other appropriate adhesive, ensuring that you properly clean and rough up the tank's receiving surface. Ought to be a walk in the park and cost you really nothing if you have the scrap material around and a drill and tap.

Mark

 

[Streetgang]

Re: 6 hole fuel sender replacement options

I may have surfed through here a bit later for the OP but will throw my 2 cents out in case it helps anyone down the road.

My company makes tanks (not boat type) and we install standard 5 hole, weld flanges and many times the sending units. We purchase s/u direct from the mfr. so for reference you can get your feet wet pretty good by visiting their web sites to look over the product lines they offer. Rochester Gauge, ISSPRO, Moeller Marine and Teleflex. You can not purchase from them but would need to find a distributor such as the fine folks here at Iboats.

The OP is up a bit of a creek with this old style and perhaps some of the workarounds mentioned above are the best solution as everything else gets a bit costly and confusing. Even though the old unit is rusted up it may be worth some effort to try and clean it up.

In general, a 5 hole sending unit flange and sending unit are designed so there is only one specific match when assembling together. The reason is to take into account direction of swing arm on sending unit so that it does not hit sides, baffle if any and end of tank let alone the drawtube or other internals. Edit I now see you can adjust the float arm in 90 degree increments.

Also, the fuel gauge and the sending unit must have matching OHM ranges in order to read accurately. A very common OHM range is 33-240 ohms. It is also referred to as a Stewart Warner style. But, keep in mind there are others such as 0-90, etc.

There are also a variety of sending units you will need to consider. Some have an adjustable stem and adjustable swing arm. Others, only have an adjustable swing arm and finally some are fixed with no adjustment. No matter the type you will need to insure it doesnt interfere when installed.

I could probably comp you a sending unit flange but that still doesnt solve your problem. Correct method to install would be to have it welded to tank and then tested which is going to run some bucks. I am guessing the tank and boat is older so tank may be terne plate / galvanized and welders dont like working on them as bad fumes let alone s/u flanges are commonly carbon steel or aluminum so dis-similar materials. Then tank would need pressure testing.

I did some searching on web and can find some 6 bolt sending units, looks like Willys Jeep and and some others used them but pricey. Remember would still have to match OHM range to gauge and them make sure could be adjusted.......

I think in one of the sticky notes, just cant remember which forum are a listing of boat salvage yards so possibly could find the exact same s/u but will leave that to you.

Good luck. Just trying to keep the waters clear and hope I havent made this too murky.

 

[81_chapparel194]

Re: 6 hole fuel sender replacement options

Also, the fuel gauge and the sending unit must have matching OHM ranges in order to read accurately. A very common OHM range is 33-240 ohms. It is also referred to as a Stewart Warner style. But, keep in mind there are others such as 0-90, etc.)

not meaning to hijack.. apologies in advance.

a quick question since i am about to replace my sending unit (5 hole) how do i know what my meter ohm range is? should i replace both together? as i can buy a s/u and guage for not much more than a s/u alone. i assume my current set up is the 33-240 ohms but not 100% sure is the guage stamped maybe to tell me?

thread unhijack) but this question could be valuable for the OP also

 

[Streetgang]

Re: 6 hole fuel sender replacement options

Update:

I made a mistake in info above when saying the swing arm is is a fixed position, hence the very specific 5 hole pattern. After looking over the offerings in the fuel tanks section of Iboats I see they have a wide variety of mfrs. units and most have ability to change position of swing arm in 90 degree increments, so can miss bulkheads, baffles, drawtubes, heads, etc. My experience is mostly from OE side and I was negligent in not checking specs for aftermarket.

I also checked and looks like ohm ranges on Iboats are primarily 33-240, although you should verify that yourself when checking.

Unless your old s/u is totally shot you can put an OHM meter on and run the float arm through its cylce and read the resistance. I am betting most of the gauges here on Iboats are 33-240 so probably threw too much info out here and muddied the waters.

My apologies.

 

[sixdeep]

Re: 6 hole fuel sender replacement options

Thanks for the info guys. When i say the original unit is rusted up i mean its now 1 piece of rust, looks like its been laying in salt water since the titanic went down, in fact i think the titanic is in better condition.
The fuel tank is a large in floor stainless steel unit. I've ordered one of these WEMA solid state units with matching gauge.

I think i'll either cover the original hole with an aluminium plate and drill a new hole for the 5 bolt unit or i may be able fit the 5 bolt on top of this blanking plate depending on clearance to the floor cover.