Captain Obvious

Welcome to old Z ownership.

Once you have shorted out the 5 Ohm resistor, it really doesn't matter if you leave it there or clip it out. However, I have no idea as to the validity of that "fix". Without doing some reverse engineering I cannot provide any input into what that modification does or if it's really a good idea or not. The guy in that video seemed confident in it, but I'm not confident in his confidence. He said something about "running the numbers" and "that resistor in there reduces the voltage"... Well, without seeing a schematic, I'm not sure at all what that means. Might be harmless, might not. Is this a common thing that a lot of people mess with? I might have a spare tach around here somewhere...

So that was "Physics" class? Potentially followed by "Pre-Med"? Haha!! What's your build month/year on your door jamb plate? If you've got a full sized spare, I'm thinking that here in the US, we could call your car a 76, not a 77.

Got your DM and I'll get some springs out to you. Have you verified that your distributor is actually supposed to have two springs? I find it hard to believe it wouldn't, but stranger things have happened. Haha!

Now THERE'S something you don't see every day!

Glad to help. To summarize the sealant the sealant stuff... I've never seen a silicone RTV sealant that said it was recommended to be used in a gasoline environment. All of the ones I've looked at say "not for head gaskets or for contact with gasoline". And while the RTV stuff won't instantly dissolve or burn down, fall over, and sink into the swamp... You can do better. I tried that Motoseal stuff because the package actually said "Gasoline resistant" on it and I've been satisfied in those applications. I'm sure there are other options. All that said... I would NOT use the Motoseal between your carb domes and the bodies. I'd be worried that it would work TOO well and you wouldn't be able to get the domes back off easily. For that application, you want something that doesn't work "as well".

The trick is that the Motoseal is not an RTV (like the Ultra or Supra Grey stuff). Instead, it is a solvent evaporation cure based sealant and not a silicone. Once the solvent evaporates, the rubbery solids remains are not particularly soluble in gasoline. According to the MSDS, it mostly uses the following: XYLENE 2-BUTOXYETHANOL ETHYL BENZENE If you can't find that brand name, there's got to be something within your shores that is similar. Finding it is the trick though.

Neither of those are what I recommend for gasoline intensive applications. Both of those are the grey RTV silicone that I used to use everywhere before I discovered the MotoSeal. (The Ultra Grey is what they cell it here. And from what I can tell, the "Supra" (not Super) is what they call it elsewhere on the globe but it's the same RTV.) I took a look at ebay UK and found the stuff, but I didn't find anything IN the UK. It's all shipped from the US or Lithuania. I'm guessing they don't sell it in the UK. Here's a pic from your ebay of the MotoSeal: And another pic of the same stuff in a different package:

No problem. Good luck with the parts and I hope they have what they say they do! Let me know if you need a spring or two if the other stuff doesn't pan out.

Thanks Wayne! So AK, I'm not sure if you've got the access hole or not. Your sheet metal deck looks different than mine. Starting in 77 they put the stiffener frame rails on the interior side (top side) instead of underneath (gas tank side). My guess is that since they had to use the raised floor for the spare tire anyway, they figured they had the room and moved the stiffener braces. It doesn't look like you've got those braces. Another way to tell... Do you have a full sized spare, or the collapsible inflatable one? I'm thinking you've got the full sized spare and rear decking that we would call "76" over here. There's no guarantee that what we call "77" over here has to be the same as what you got in the UK.

So I'm confused then... If you got the "improved" 77-78 cars, it sounds like (other than the engine), it's the same thing I have. So why don't you have that convenient access port-hole in the rear deck for the fuel sender unit? is yours an early 77 or something?

Well I found the distributor basket case I was thinking about, and it's a D6K82, so I was apparently very wrong about it being from a 240. In fact, the info I have indicates it's at the complete other end of the spectrum and came from an 83 Non-turbo. But here's the good news... The mechanical advance specs are similar to your D612, and if your distributor is SUPPOSED to have two springs, then I would assume that using one spring from my basket case is going to be way closer to the original design than just one spring. in yours So short story? Whatever you want from this distributor is yours for the shipping. Just let me know.

Well honestly, I was mostly kidding since @AK260 left me little choice with my first comment. But some more detail? I'm no sealant expert, but I think that in the application where AK used RTV silicone, it'll be "fine". It's not bathed in gasoline, and it's what I would consider a "low stress" application. I wouldn't use it to seal the fuel bowl gaskets or the carb to intake manifold, but at the end of that throttle shaft, I think it will be good enough. So after posting last night, I was able to poke around on the computer a little and found some detail about my testing and my pics. I don't remember what type of carb I was messing with that spurred me into the experiments, but I did the following... I put a dab of both Permatex Ultra-Gray silicone (my go-to) and MotoSeal on an index card and let them both cure for a couple days. Looked like this: Then I cut the little dabs out of the index card and gave them a couple day immersion bath in gasoline: Then I took them out and gave them and compared the results. Here's the ultra-scientific "poke test": MotoSeal after poking: Silicone poke: Silicone after poke: And here's the summary result: And then after the soaking, I let them sit on the bench and dry out for a couple more days, and here's the results of that: So after that testing, I've stopped using the Ultra-Gray and have switched over to MotoSeal in gasoline intensive applications,. I still use the Ultra-Gray for most everything else that doesn't involve potential direct exposure to gasoline.

I used to use that silicone RTV style for pretty much everything, but a couple years ago I switched over to Pertmatex MotoSeal for gasoline intensive applications. I don't know if you've got something similar on your part of the globe, but I assume you could find something. I ran some tests on both in gasoline, and the MotoSeal came out to be the clear winner. I think I've got some pics around here somewhere if I could only find them...

You used the wrong paste.

Haha!! Glad to help! Advice? Don't try to operate with just one spring. That will throw off the mechanical advance curve. Too much advance at too low of an RPM. I think distributors are easy to find. Might be easier to replace the whole thing than to get one spring. I've got a 240 distributor that came to me disassembled and incomplete... Don't know what year it's from though. What is the number on the side of yours?

Those are later 280 rails. 77-78 only I believe.

Haha! Probably took a lot of testing and revising to get that just right! So you don't have that 77 style hatch? I knew the UK stopped engine sizes and carb evolution with the 260, but I thought the rest of the car was the same as the US. So your entire car, body stampings, electrical, all that? All that stagnated* in 1974 and held through until 79? * Not intended to be derogatory. Used for description only.

@AK260, I had a few spare minutes yesterday, so I took a quick preliminary look at my fuel gauge system. Not sure if all the years have this, but my 77 has a convenient access port in the rear deck to get to the tank sender unit: Take the screws out and pop the cover: I pulled the wiring up a little and found the connector between the body harness and the sender unit. Looks a little crusty, but it's not green. Disconnected it and then took turns grounding the gauge connection and the "FUEL" warning lamp connection: Here's what my fuel gauge does when the sender wire is grounded. Clearly my gauge itself and all the connections leading back to the sender are fine: And just since I was working back there, I verified that my fuel lamp works when I ground the other wire: So I cleaned up that connector and put it back together. I don't know if doing just that will have much effect on the needle position on my gauge. I'm assuming that most of my issue is within the sender unit inside the tank and I'm not going to pull that to mess with it until I'm really ready. I won't know if simply cleaning that one connector up did anything until I fill up next time. I'll keep you posted.

I don't have a copy of the 71, but I found some adjustment info in the 72 manual. EC-19 and EC-20.

Oh, and remember... That's just one gauge that I had laying around. I have no idea how much variability there would be if I were to test a bunch of them and average the results. I suspect the gauges themselves are relatively consistent, but without testing, that's speculation.

I have the same situation. Never gets to F, and I still have about three gallons in the tank* when the needle is on "E". I need to clean some contacts as well, but it's just further down the priority list. *estimated knowing the claimed FEM tank volume versus how much I can put in at fill-up.

I made that picture. I hooked the gauge up on the bench and tested it and that's what I got.

Yeah, that's early alright! I bet those are the original carbs that came on that 240. Even if you do change to something different, keep those in a box on a shelf somewhere. If it were me, I'd pick up a set of cheap round tops and do the refurb work to them myself. But I've been into them before and I ain't skeered. If you got the money and want someone else to stand behind the work, then ZT seem to be the go-to guys. One thing to remember... If you decide to go with round tops, you'll also need the linkage bits that connect the front carb to the back carb. The round tops are narrower than the flat-tops and your original flat-top linkage will be too short. But in all honesty, I'd pick up a pair of later generation flat tops and go down with the ship. Haha!!

It was bugging me, so I had another look. 1974 FSM Engine Tune-Up section. ET-16. Thorough description of the system along with way too complicate adjustment procedures. I stand by my "between squat and too long", but if you want to follow the factory's procedure... Their description is on ET-21 and 22. Good luck.