73 atc70 project

[Tomcall]

Matt
I just ordered an oem cap. Wish me luck

[MattDragontamer]

So did ya get it yet?

[Tomcall]

Matt
Yes, I did and no difference.
Another thing I tried was ordering a gas cap for the 78-80 atc70. It is a little different style and I tried with shaking the trike and it was ok, but I need to go for a test ride to be sure. Someone had told me about a cap that screws in 90 degrees and has a ket that you keep turning to crank the cap down. He said he saw it on ebay, but I have not been able to find it. I wrote him but no response yet.
I'll let you know how the test ride goes.

[MattDragontamer]

For your case, you should be able to bend the lock tabs in the gas cap if it will give you the seal.

[Tomcall]

Been awhile - Well still leaks gas and tried all the ideas except cutting out the top and getting a good opening off another tank and having it brazed on.
Meanwhile I did find another stock tank that has only a small dent and rusted inside. It has 74 decals but the tanks seem identical for 73 and 74. I am going to try fixing the dent with "lab metal". Someone mentioned it another thread on here and I watched several u-tube videos about it.
I have had terrific results using "evaporust" to remove the inside rust. I'll then coat it with "red coat".
I will look into finding and old beat up atc 70 rank to use to repair the black tank.

Meanwhile I installed steel braided fuel lines. What do you think? I'm not sure about it. i may go with the red braided lines instead.

[Flyingw]

Tom, did you get the ignition problems resolved?

[danbur55]

would double gasket the cap do anything? is there a way to pressurize the tank to maybe force the tank to rise up a little but not sure that would do any good for sealing the cap

[Tomcall]

Jim-
I have this 70 running fine with the cdi unit installed. It is interesting that I can turn the pilot screw all the way in and get higher rpms??? When I called Spanglers they said so what's the problem!!!! I said it's not normal that's the problem. Ended up talking about a possible air leak. They suggested spraying carb cleaner on the manifold and whatever to see if it increased the rpms and that would indicate a leak. I tried that and no change in rpms. I swapped pilot screws with my 74 and no difference. I give up on that. It runs really strong so f**k it. It's the 74 atc70 that has given me ignition fits. I ordered and just received a new ignition coil today. I will let you know if that does the trick.

danbur55 - I tried double up on the gasket but it leaves no room to grab the tank. I don't know about pressurizing, but when you look at the opening it just looks almost like it's worn down as much as pushed down.

[coolpool]

That sucks about your gas cap. I too have a slight "in-nee" gas cap on my 73. The picture Matt supplied was an ugly OEM replacement that worked for me since all old style caps leaked. We really thought that would do it with the thicker gasket for your issue. I've attached a picture with a crude tool design that may allow you to "pop" up your filler neck slightly. Basically it's a collapsible cross that spreads open once inside then has a slide attached to a flexible shaft. I know it's a pretty small opening, but if you use strong enough materials it may work. Grasping for straws here

[crazycooter]

Cool trike! I have a few 70's too and love them.
"coolpool" has what looks like a good fix. I have also had a sealing issues and just used a body and a u shaped tool I made that acted like the dolly that fit on in side of the sealing surface and moved it around to line up to where I was ing.Then use a straight edge all the way around to make sure its nice and flat.
You would need to remove that stuff that looks like its JB weld first and and dolly clean steel.
Like somebody else said earlier, you can play with the tension of the seal on the tank buy bending the tabs on the cap. Also make sure the area the tabs contact are the same and undamaged.
Turing the Pilot screw all the way on on lots of these smaller bore motors sometimes wont actually make it stall out, it will just lean it out and cause higher rpm.
If its too far gone you can buy this for $7 and weld on:
http://www.lowbrowcustoms.com/p3138/...-weld-in-bung/

[Tomcall]

coolpool
That is a good idea, thanks. I had used a bearing puller, but it only grabs the edges and it moved it just a little. Your idea would grab the whole top part of the opening.
What material did you use for this idea?

crazycooter
I didn't know you could buy the bung. Thanks for that link. I did buy the bung and will use it as a last resort.

[coolpool]

coolpool
That is a good idea, thanks. I had used a bearing puller, but it only grabs the edges and it moved it just a little. Your idea would grab the whole top part of the opening.
What material did you use for this idea?

crazycooter
I didn't know you could buy the bung. Thanks for that link. I did buy the bung and will use it as a last resort.

I haven't actually built one Tomcall and I know it's size will be a challenge, I drew this up as a suggestion for your situation. My leak has stopped with the new style of cap.

[Tomcall]

coolpool,
I get it. I was going to ask if I could rent it from you. lol

[Tomcall]

Well, time goes by doesn't it.
So I did purchase the bung and vented fuel cap. It is larger than stock and so is the fuel cap. Thanks to Mr. Richard the bung was installed. He did a very nice job. It has red coat on the inside and he managed to barely mess with it. From there it need some body work and re-paint. Turns out the tank had a lot of work previously done to it as Mr. Richard discovered installing the bung. Powder coating never would have worked. I saw the tank last Friday, but it was not done drying and they still need to put the decals on and then clear coat. Hope to have it back this Monday evening. The body shop has done a very nice job filling in around the bung. I will post some pics when I get it back.
Thanks again Mr. Richard for your fine skills and suggestions.

[lyon76]

That is a nice 70 man!!!