Fuel tank expansion due to ethanol

[gstallons]

Let me throw this in . I do have a two tank system on the black frame . with the red tank (NEW) having only non-ethanol fuel only used . The tank still was a JOB to remove / install with paint rubbed off in places I didn't like . I am going to say mods to the front tank pucks are the only way to go w/o aluminum .

[Lucky Phil]

16 hours ago, gstallons said:

Let me throw this in . I do have a two tank system on the black frame . with the red tank (NEW) having only non-ethanol fuel only used . The tank still was a JOB to remove / install with paint rubbed off in places I didn't like . I am going to say mods to the front tank pucks are the only way to go w/o aluminum .

The std tank benefits from greasing the rubber pucks when installing the tank. My greeny tank is the same size as the day it left the factory, never seen ethanol though.

Ciao 

[po18guy]

OK, frame spuds on an eccentric. Or spring-loaded fore-aft spuds. Don't want the tank loose, but don't want it to  "banana" from being squeezed. 

I have a 1982 650 Seca with a tank I coated in 1983 (new replacement) with aircraft tank slushing compound. Fuller-O'Brien used to make it. It's still there. Still rubbery-tacky.

Chuck will know.

[Lucky Phil]

4 hours ago, po18guy said:

OK, frame spuds on an eccentric. Or spring-loaded fore-aft spuds. Don't want the tank loose, but don't want it to  "banana" from being squeezed. 

I have a 1982 650 Seca with a tank I coated in 1983 (new replacement) with aircraft tank slushing compound. Fuller-O'Brien used to make it. It's still there. Still rubbery-tacky.

Chuck will know.

Here's what I did with the V11/V10 front tank mount. I could design a simpler setup for a std V11 with fore and aft adjustability but it would raise the front of the tank maybe 10mm which wouldn't matter and probably be hard to pick. My V11/V10 mount raised the tank 40mm which was necessary so I thought I may as well make it adjustable.

The tank sealant I used on the commercial jet fuel tanks for 40 years was PR-1422. The "A" was the runny one and the "B" the non runny version.

Ciao 

[po18guy]

Yes, very cool, that. Will have to pull my tank to see how they messed up (designed) the black frames. Ugh. Well, it ain't running anyway.

Say, any room for a 12V computer fan atop that rectifier? I know that on Kwackers, they die a lot from heat.

[Lucky Phil]

35 minutes ago, po18guy said:

Yes, very cool, that. Will have to pull my tank to see how they messed up (designed) the black frames. Ugh. Well, it ain't running anyway.

Say, any room for a 12V computer fan atop that rectifier? I know that on Kwackers, they die a lot from heat.

Probably would be there's quite a bit of room under there now which helps the cooling but I'll see how it goes. Its in a way better location than my 1198 and they seem to last ok. 

Ciao

[po18guy]

For those so inclined...I just received this tank sealer special from KBS Coatings. Coupon code J121 will get 15% off. They describe fiberglass tanks in their instructions, but it seems that nylon would also be treatable. 

[Tom in Virginia]

On 1/29/2021 at 5:08 AM, Lucky Phil said:

Here's what I did with the V11/V10 front tank mount. I could design a simpler setup for a std V11 with fore and aft adjustability but it would raise the front of the tank maybe 10mm which wouldn't matter and probably be hard to pick. My V11/V10 mount raised the tank 40mm which was necessary so I thought I may as well make it adjustable.

The tank sealant I used on the commercial jet fuel tanks for 40 years was PR-1422. The "A" was the runny one and the "B" the non runny version.

Ciao 

Now that is simply art there Lucky Phil!

 

[gstallons]

I cut an arc 10mm thick off the pucks and about 1/3 around . Drilled and pinned them so they wouldn't spin and installed the tank . P.S. the leak was at the retaining nut . Installed another sensor (used) from a 2000 tank & had to swap connector because it was DIFFERENT . 

 BTW , the tank fell onto the bike !

 

 

[Lucky Phil]

14 minutes ago, Tom in Virginia said:

Now that is simply art there Lucky Phil!

 

It took me a while to design it, I'm not fast like that. All the fasteners and bushes are Titanium. The 4 nuts on the on the 6mm fore/aft adjustment bolts are superficious and I may remove them at some point for a neater look. The base of the vertical legs rest on the frame top rail to control any possibility of any rocking movement. I wanted something that could be restored to original without any welding etc.

Ciao 

[docc]

1 hour ago, gstallons said:

I cut an arc 10mm thick off the pucks and about 1/3 around . Drilled and pinned them so they wouldn't spin and installed the tank . P.S. the leak was at the retaining nut . Installed another sensor (used) from a 2000 tank & had to swap connector because it was DIFFERENT . 

 BTW , the tank fell onto the bike !

 

 

WHAAAAT!?!? No beers?

[gstallons]

That's right ....... Anyone removing their fuel tank needs to do this. It also gave me clearance at the rear of the BRAND NEW PRISTINE condition tank I installed  couple of years ago that rubbed the paint off in a few places from expansion . 

I am still not smart enough to post pics , but I ground down to the top of the lettering on the pucks .

[Lucky Phil]

On 10/8/2020 at 4:08 PM, po18guy said:

Plastic contains chemicals which, by class, are known as plasticizers. They lend the flexibility and resilience to the base material. With heat and time, these plasticizers migrate out, through oxidation, heat cycles, sunlight (UV) or exosure to other chemicals and solvents. Thus old plastic of virtually all types becomes brittle. It usually shrinks, as its component parts leech out. But Guzzi tanks expand. That is from the chemical content of the gasoline  which they store. Ever clean rubber parts with alcohol? Some types will blow up like a balloon. Add that alcohol to gasoline and you get the same result.

It's not that. The reasons have been identified, and it's water. The nylon tank material absorbs water and swells and fuels that contain ethanol are more hydroscopic than straight fuel and have a higher moisture content and therefore swell the tank.

Leaving them dry for a few months in a warm dry environment pretty much brings them back 100% as the water leaches out of the Nylon tank material. 

Ciao