Fuel line questions

[sevy]

So...I have read the other fuel line threads, and I am still befuddled. I understand that you are making new lines out of 5/16 steel brake lines, but my question is what are the ends?
The current set up on my Cub was obviously jury rigged by some previous owner, and while it has not been leaking, I wanted to replace it with the correct set up, especially since my exhaust goes to the rear and not up (the tractor's exhaust, not mine )

Currently, this is my sight glass body:





And this is the end which attaches (with a ferrule):



Looking at the inside of the sight glass body, I don't see how a regular flared end would seal?

At the carb end, There is a brass pipe fitting (tapered I think), which then screws to a brass compression fitting with a ferrule, just like the other end. Here is the carb body:



Again, I don't see how a flared end would seal in there.
I suspect someone buggered these all up at one time, but I would like to put it back to stock. I bought some packing thread with graphite to help seal the shut off, and a new sight glass gasket from NAPA made of rubber. The last few cork gaskets I got from IH warped badly and then leaked almost immediately. I will use some Blue Hylomar on the upper side of the gasket to keep it on the housing better, as trying to reattach the glass after emptying debris with the tank in place requires more hands and dexterity than I apparently possess, and my pet octopus just died, so there is that as well

Any suggestions would be most appreciated!

[John *.?-!.* cub owner]

The way is to cut the ends off the brake lines, bend them to shape, then put the ferule ends on. The ferules and nuts are available at most any auto parts place, just take your old one so they can see for sure what you need. I prefer the lines from Autozone, they are easier to bend and have the nice black anodized coating, but that is just my preference.

[sevy]

Thank you for that! So, the ferruled ends were actually the original connections, or is this just the easiest way to use what I have already got in place?

[Bob McCarty]

From TM Tractor, here is the correct fitting: http://www.tmtractor.com/new/fl/512fp.htm
The threads are 1/2-20 although they look like a pipe thread and often get stripped out and need to be helicoiled.

Bob

[staninlowerAL]

John has you covered. The OEM fuel shutoff valve fuel outlet and carb inlet are 1/2 x 20 thread, not tapered so if you have something different then it's been jury-rigged. It is possible to use a 5/16 compression union fitting in these locations but you wil have to discard one of the compression nuts and ferrules then rethread the end that screws into the carb and fuel shutoff with a 1/2 x 20 bolt die nut. The advantage of this type connection is that you will probably not have to screw anything back into the carb or fuel shutoff, which both are notorious for easy crossthreading and damaging the soft metal. The other option to correct bad threads is to use a helicoil. Just my 2 cents worth. Sta

[sevy]

Thanks! I think I will get the helicoil at the carb end to get rid of the two pieces that are there now. The other end is apparently okay. The ferrules are actually a better deal, since I won't have to worry about finding my old flaring tool!

[Bob McCarty]

Sevy, The helicoil is a little tricky to do. Rick Prentice came up with a pilot guide to allow an end mill to cut the ID of the inlet to the correct size for the STI tap. If it's crooked at all, the fitting will not go in straight. There are lots of forum members that have the guide and I'd suggest you find one close to you to do the helicoil. Until then, continue with what you have.

Bob

[sevy]

Okay, will do. Thanks!

[Rudi]

this is my solution and it is now a standard upgrade for any Cub I purchase - How To Upgrade A Cub Fuel System .. I have one on the waiting list right now ..

[sevy]

I used three different pulley sizes for bending jigs, and with some careful effort and patience was able to create a steel fuel line that works perfectly. I took the carb apart and cleaned it with some Mercury/Johnson outboard cleaning spray, which I then washed off with water, and finally sprayed the water out of the orifices with carb cleaner (I didn't have a compressor available). It started instantly and has never run so well, so I think the carb had some snot inside, and the improved airtight fuel line can't have hurt either.
Time to get the sickle bar mower installed and get my fields cut!
Thanks for the help!

[pickerandsinger]

The way is to cut the ends off the brake lines, bend them to shape, then put the ferule ends on. The ferules and nuts are available at most any auto parts place, just take your old one so they can see for sure what you need. I prefer the lines from Autozone, they are easier to bend and have the nice black anodized coating, but that is just my preference.

……NAPA has a dark grey line that is similar to what John mentioned from Auto Zone, that I have used and it bends nicely for a steel line if you don't have access to Autozone…Dave

[sevy]

I forgot to mention another issue that I solved when I was doing this project, and that was the shutoff for the sight glass. Until I took it apart, I didn't realize that when opening the shutoff it needs to be unscrewed all the way until the brass ridge inside seats on the collar so as to prevent air from getting by. I had always just opened it a turn or so, and this may have contributed to the rough running I was experiencing?
Just started cutting my hay for this season, and it runs flawlessly now. Really a perfect design for the Adirondack "fields" I mow to keep them from going to brush, as everything is side hill and full of big rocks and boulders. The cub sits high enough to clear most of these, and the visibility looking down on the sickle bar in front of you allows you to lift the bar and miss most of the stuff before you hit it. After several hours of this rough ground mowing, I feel like I have been in a gym all day, as you take quite a pounding just staying on board!