2-piece gas tank reseal

[Bar Nuthin 3,336]

The 754 has had the fuel tank apart and whoever did it used some kind of gummy sealant on both sides of the gasket. I noticed that it randomly shed drips of gasoline. By randomly, Maybe a drop or two one day - then dry for 3 or 4 days, then a drip - not necessarily in the same location.

So, I took it off today and opened it up. The first thing I noticed is that none of the Allen head screws holding together were very tight.

The second thing I noticed is that one of the threaded holes appears to have been repaired with JB Weld (or something similar).

Perhaps that was their reasoning for not over-tightening the screws. The gasket is still perfectly flat with no indentation from being compressed, and the use of whatever kind of gasket varnish it was coated in.

 

Anyway, the repaired crack appears to be contained to the inner side of the tank and everything else seems okay to my unexperienced eyes.

I'm ordering a new gasket but looking for tips or advice from anyone who has had these tanks apart, or experienced anything similar.

 

EDIT: I see Lowell references "Permatex Aviation Sealant" - possibly the goop I found on my tank?  Anyone using something better?

 

 

 

 

 

Edited 13 hours ago by Bar Nuthin

[Racinbob 13,207]

I've had several of those 2 piece tanks and never one that didn't leak to some extent. I don't think there's a gasket coating that exists that will permanently stop the issue. Really it's just a bad design. Wheel Horse came out with a service bulletin on it which involved actually installing an inner tank to solve the issue. I think I found a better method.

 

 

There's many fuel tank liners out there and they will likely work as well but I've never tried them so I can't vouch for them but I know this stuff works. I think I can say permanent  because I've never had one leak after using it.

 

The key to it is cleanliness. I removed the old gasket and cleaned everything until it was sterile. I reassembled it and did some more cleaning. I let it sit in the sun several days to make sure any trace of moisture was gone. I plugged the threaded hole with a nylon fitting. I used maybe a quarter cup of Red Kote and swirled it around the edge where the two pieces meet. It doesn't take much. You don't need to coat the entire tank, just where the seal is. I let it dry several days and repeated. When I was done with the sealer I let it dry for many days. The latest one I've done is my current 854 and that's been 8 years now. 

 

 

 

[sqrlgtr 4,043]

but the sealer I use is called "KREEM" and I just go ahead and do entire tank. 

[WHX?? 58,276]

I used this KBS product on a 502 two piecer that @Andy N. now has. I was too sceered to take it apart for fear of bad threads. 'Sides figured by the time I got a gasket from Lowell and Permatex and possibly dealing with bad threads i was ahead. 

  I was sold on this brand since I used it before on a Tecky oval tank that was full of pin holes with great luck. . I soldered up the biggest holes and the ones I missed had the seal gooing out which I considered a good sign. 

 

The big thing with this product is use all three components and follow the destructions to the letter. 

 

https://www.amazon.com/KBS-Coatings-52000-Sealer-Gallon/dp/B000IBDIX2/ref=sr_1_1?crid=176XR3BJQCOI&dib=eyJ2IjoiMSJ9.VRrcUbU1iANAvxPODhOQO3xt4DcrZWHcPSX9eZkdvpHNP0AC30S3mP6VPjtv37JPU2A2RJNaGbc8AmnTHRce8DIMeiJSqdUGig2reSj9k6XZhdY1NzqYLYl4jql6C5yxmVYB0ZFbrT28pgq5FqILHabaGezHzaV1IZ2vFvNV3whPFCC_HFrMsqdB4A_bMmbNBSp9eb_Ari5mNfQ_9LednHWKBRRpZeGOY_7yRFFb17yWDM2Gi2bqk0CWJ30gDQHETMdV444TCG6aL54YwpIM6xTZ2Ic3zOJz_dFeuT-MWjM.xIbyvN4P2rS1Xo9cNfEOAlhKVgq439WeW2G6P6b43vI&dib_tag=se&keywords=kbs+tank+sealer+kit&qid=1792930810&sprefix=kbs+tank%2Caps%2C205&sr=8-1&ufe=app_do%3Aamzn1.fos.9fe8cbfa-bf43-43d1-a707-3f4e65a4b666

[ri702bill 13,144]

4 hours ago, Racinbob said:

Wheel Horse came out with a service bulletin on it which involved actually installing an inner tank to solve the issue. I think I found a better method.

The issues with that "approved" method - it ruined an otherwise good tank. The inner tank was most likely meant for a walk behind lawnmower - it held a QUART of gas! IMHO - not really a fix. Perhaps they should have just ponied up and brought back the 701 / 702 one piece tank??

[Handy Don 17,528]

2 hours ago, ri702bill said:

Perhaps they should have just ponied up and brought back the 701 / 702 one piece tank??

As you are very aware, aluminum castings like the 701/702 tank are very challenging to manufacture. I’m betting the two-piece, even with the extra parts and labor to assemble, was substantially less expensive and, I’d suspect that the vendor that made the one-piece tanks had shut down their line. 

No big surprise that so many fuel tanks today are blow-molded plastic. 

[Bar Nuthin 3,336]

Currently, I think my plan is to ..

1. Glass bead (fine) the tank inside and out to clean up any corrosion
2. Install the gasket ($10 eBay) dry with no goop
3. Red Seal the inside of the tank
4. Apply a satin (or matte) 2K clearcoat to the outside of the tank.

Thoughts?

Edited 1 hour ago by Bar Nuthin

[Racinbob 13,207]

3 hours ago, ri702bill said:

The issues with that "approved" method - it ruined an otherwise good tank. The inner tank was most likely meant for a walk behind lawnmower - it held a QUART of gas! IMHO - not really a fix. Perhaps they should have just ponied up and brought back the 701 / 702 one piece tank??

 

I agree but it's what they did back then. They did address the reduced capacity. The original was 4 quarts, the replacement 2 quarts. They mentioned if that was a problem to seal the tank. The problem back then could have been not having the selection of tank sealers that we have now.

 

47 minutes ago, Bar Nuthin said:

Currently, I think my plan is to ..

1. Glass bead (fine) the tank inside and out to clean up any corrosion
2. Install the gasket ($10 eBay) dry with no goop
3. Red Seal the inside of the tank
4. Apply a satin (or matte) 2K clearcoat to the outside of the tank.

Thoughts?

 

I like that idea. I've done it with gasket goop and without and also without removing the bottom plate. Same results with all. 

 

Edit Check out Bulletin #348 if you want to see the old Wheel Horse fix. 

Edited 43 minutes ago by Racinbob

[Handy Don 17,528]

27 minutes ago, Bar Nuthin said:

Thoughts?

I was faced with a slow leak at the seam of the two-piece tank on my 854. I eventually realized it had been very slightly dented, probably due to an impact. I was able to remove all but one of the screws holding the bottom (they were not stainless Allens like you have). At that point, to truncate my loss, I gave up and, because I wasn’t trying for authenticity, went with a 702 tank which then led to making a custom dashboard.
Your plan sounds good. There are very few sealants/adhesives/fillers that are truly impervious to gasoline so sticking (pun intended) with one that is should reward you. 

[ri702bill 13,144]

Some folks have had good sucess TIG welding the base to the body.... some folks.

IMHO - this is not a Saturday afternoon backyard project to try out that new HFT Welder. 

Welding the thin base requires a good machine and the skill to weld it.

The use of RedKote or a comparable epoxy sealer is a sound idea.

Edited 39 minutes ago by ri702bill