Tank "gelcoat" blisters

[grumpyguzzi]

Anybody else seen this? My brother "gifted" this 2011 Norge to me and he says it's because the tank is plastic and is always expanding & contracting. Just curious. It's got some minor road rash on the left side (I didn't do it) that I'm attending to also. Don't know if I'll attempt to fix the side case or just see if I can find another one. If the Norge badge will come off easy that will be a quick fix.

[Ratso88]

Check the fuel tank vents to ensure they are not clogged. There may be a check valve to prevent fuel leaking on you if you're upside down, feel free to replace it with a brass barbed connection, some just forget how to work. You don't plan on being upside down under the bike do you?
That should fix the expanding tank issue.

The plastic tank paint blistering repair is something I have no experience with on Guzzis.
Other bikes, non plastic tanks, I've used Caswell Fuel Tank Sealer with good results.

Some more experienced hands will come along soon and set you on the correct course.

[lucky phil]

Anybody else seen this? My brother "gifted" this 2011 Norge to me and he says it's because the tank is plastic and is always expanding & contracting. Just curious. It's got some minor road rash on the left side (I didn't do it) that I'm attending to also. Don't know if I'll attempt to fix the side case or just see if I can find another one. If the Norge badge will come off easy that will be a quick fix.

The plastic tank is affected by Ethanol fuel and it has damaged the paint. It's actually the water in the fuel that does the damage not the actual Ethanol. The Ethanol attracts the water and then it swells the tank and permeates through in some cases. You need to remove the tank empty out of all fuel and leave it to dry out in a warm dry area for a few months. The tanks generally contract again to much the same as when new.The paint is ruined and must be removed by blasting and the tank preferably coated internally and then repainted. Different people have had different results with coating nylon tanks. Some succeed and some fail it seems a bit hit and miss.
Easier to buy a good second hand tank I think and dont use Etanol fuel if at all possible.

Ciao

[Motormike]

Very common sight on the old tube frame Buell's with their plastic fuel tanks.  Over time (usually several years) the fuel vapors permeate through the tank material until they reach the paint membrane...presto, a bubble!  And then another, and another, till your tank looks like it has small pox.  For years, I would pop them like a zit and smooch the pant back down.  Finally gave up and Caswell coated the inside of the tank and had it repainted.  That has lasted for over ten years.  Look up Permeability and plastics.  You'd be surprised what gas fumes are able to leach through, given enough time.

[Bert Remington]

I second lucky phil -- replace the tank.  A quick test to confirm this is necessary.  Remove the seat then remove the bolt at the rear holding it down.  Lift the tank up a few inches then let it down.  Insert the bolt.  If you can screw it back in without difficulty your tank is blistered but not expanded.  If you need to push hard to insert the bolt your tank has expanded and you need to replace it.  I had to use a tie down strap to force my tank into place.  Bought a flawless replacement for $150 (marked for a Breva but they're all the same) but then a few months later managed a right hand driveway tipover into a fence post so no longer flawless.

DON'T DON'T buy a replacement tank that has any bubbles no matter how small.  Preferably a 2013 or later tank.

Replacing the tank is easy.  Just swap over the fuel pump and cap being careful with the gaskets and tightening torque (incremental multiple times until you reach final torque -- don't overtighten).  As described above just combine the two vent lines into one and run behind right side of transmission.

The Norge is Italian gorgeous but it is a Moto Guzzi (Making Mechanics Out of Riders Since 1921).  Buy a service manual and a set of T-handle hex wrenches...as a starting point.  And do an end-to-end fastener check.  Many of mine were misplaced or simply wrong so I moved the hidden ones to visible locations and put ordinary fasteners in the hidden places.  I'm serious about end-to-end -- every nook and cranny.   Much cheaper than buying replacement fasteners.

And what did I do with my Norge?  Gave it to a nephew 1,000 miles away.

[GeorgiaGuzzi]

Has anyone tried vinyl wrap on an effected tank? My Quota has this problem and I’m considering having the bike wrapped dark metallic green. 

[Bisbonian]

Has anyone tried vinyl wrap on an effected tank? My Quota has this problem and I’m considering having the bike wrapped dark metallic green.

Your Quota likely doesn't use the same sort of plastic the CARC bikes do. I think it has more flexible, dirtbike-like, plastic. A lot of the dirt bike stuff is quite porous and fumes escape easily.

[Bulldog9]

I had several of these on my Mahogany Brown Norge. I put the bike out in the sun, then took a sewing needle, punctured the bubble and pressed it smooth with a damp cloth. You could see 'something' but was much better than the bubble. I have several on the Griso as well and need to do the same, though I am considering painting it or getting it wrapped.  All in all, I've started appreciating patina on my bikes. Long gone are the days of gliptone spray wax after every tide top to bottom and fixing every little thing....  Perhaps it is because my own chasis is no longer shiney and new............. 

[skippy]

Well now all of you got me to thinking. Have any you removed the Evap system from your bikes? I know it was the thing to do quite a while ago on some of the early injected bikes but for the life of me I can't remember why other than maybe a check valve that would stick and cause some issues.
I really can't remember.
I do know that I removed it from my 03 Stone and my 06 B11 Breva. The Breva has not shown any signs of blistering paint or expanding tank or any such stuff. So that got my to wondering if it may be attributed the lack of the Evap system and all of that stuff.
On a side note, I would expect that Moto Guzzi and everyone else for that matter to have figured out how to make an Evap system by now that wouldn't succumb to the ill effects of crappy ethanol fuel by now but I may be wishing for too much.
Has anyone chucked their canister in the bin on a V85 yet? Does anyone remember why we chucked them in the bin 10-20 years ago?

Skippy

[grumpyguzzi]

The Norge is Italian gorgeous but it is a Moto Guzzi (Making Mechanics Out of Riders Since 1921).  Buy a service manual and a set of T-handle hex wrenches...as a starting point.  And do an end-to-end fastener check.  Many of mine were misplaced or simply wrong so I moved the hidden ones to visible locations and put ordinary fasteners in the hidden places.  I'm serious about end-to-end -- every nook and cranny.   Much cheaper than buying replacement fasteners.

And what did I do with my Norge?  Gave it to a nephew 1,000 miles away.

Very funny 

Thanks for all the input. First bike since I took a Honda Civic on head to head 11 years ago with my Suzuki GS1000G. I'm not sure I can leave it drying out for a few months. I'm going to have to pull the tank anyway since the oil pressure warning light is coming. There's an oil leak that seems to be eminating from up there somewhere. Since it is an Italian bike, I check the oil before and after every ride. It's had nothing but ethanol free fuel since I got it back in March. Of course, the damage was already done.

[Motormike]

for what it's worth, when the plastic tank on my 97 Buell began to bubble, I had it stripped and repainted.  The painter first used an epoxy based primer in an effort to "seal" the tank from the gas vapors that leach through, causing the bubbles.  That was at least 12 years ago and not a bubble or paint flaw since. 

[Bert Remington]

grumpy -- some not too bad news and some probably bad news.

First, the oil sensor is checked once when the ignition is first turned on (must be 0 ohms) and checked continuously when running (must be something non-zero).

The oil sensor is a fairly common part you can buy at Napa, etc.  The key determinant is the electrical connector. I used this for my 2012 Norge: https://www.napaonline.com/en/p/ECHOP6144?interchange=1  Easy to replace.  Access is terrible.  It will take longer than you expect.  You will get intimate with your Norge.  I used pipe sealant even though MG says don't.  USE A TORQUE WRENCH or you could be left with a leak: loose threads or stripped threads.

Here's some helpful articles:

https://wildguzzi.com/forum/index.php?topic=77673.0

https://wildguzzi.com/forum/index.php?topic=84048.0

http://blog.road2ride.com/search?updated-min=2015-01-01T00:00:00-05:00&updated-max=2016-01-01T00:00:00-05:00&max-results=10

http://blog.road2ride.com/2016/01/

Now the probably bad news.  Your oil pressure problem could be caused by a failing sump gasket.  Sometimes the oil galley surrounds get a bit weak and lose pressure.  More likely for the 8V.  Easier access than oil pressure switch.  But there are surprises.  Spend some time researching first.

[Tim Henry]

My friend in Jacksonville beach has an early norge he's afraid to remove the tank because it swelled so bad he's never going to get it back on without major damage he parked it in his shop because of a oil switch major leak. So be careful with it BTW my 15 griso tank bu bbled too and was replaced under warranty
It didn't like 89 ethanol free so 93 was it until I totaled it 4 months back I'm sure it would have done same again as it was starting to fade again to more of an orange copper color

[Bert Remington]

Apparently the Breva and Norge tanks are interchangeable.  My replacement tank was marked Breva.  Perfect fit.  Replacement tanks aren't that expensive on eBay although I was lucky and found a NOS item albeit unpacked.

I used a ratcheting tie down strap to install the original tank which I needed to remove to SURPRISE replace the leaking oil pressure sensor.  The tank was the easy part.

[Tim Henry]

I'll pass this on to him he just seamed to be pissed off at it beyond reason maybe I'll be able to change the mindset but I'm definitely liking the good old steel tank on the Calvin I got from antmanbee

[blackcat]

My 07 Norge has expanded but no bubbles and I can no longer attach the rear bolt and it's been that way for years.  I recently read that one way to deal with the expansion is to drain the gas tank and let it completely dry out, like over the winter and it should contract.  Then use non-ethanol gas from then on out if possible.

I also picked up a brand new Breva tank for chump change a few years ago, but without any blistering in the original tank I see no reason to swap tanks.

[Mayor_of_BBQ]

WHile you have the tank empty and off, chase out the drain hole/tube from around the filer neck out the bottom of the tank. A thin wire (bicycle shifter cable?) chucked into your drill should work.  these are known to accumulate some crud and plug up over time... even if it is draining now, no harm in cleaning it out a bit.  If it clogs, water from rain or washing will sit in the ring and slowly drain past the fuel cap gasket and into your gas...  that deff exacerbates the swelling/bubbling issue if you have a few mm of H2O sitting in the bottom of your tank

Ive been lucky with my Breva, I can't get ethanol free gas reliably, but ive only had minimal swelling and no bubbles so far 

[dguzzi]

I'd like to have one of those tanks, but I'm always to far away.

(its for science...)

[ohiorider]

I have to ask.  Do all these CARC bikes with blistering/bubbling tanks still have the USA emissions systems installed?  With the fuel tank vapor hoses that go into the charcoal canister?  With said hose with the in-line pressure release valve that sometimes doesn't want to release?  That causes pressure to build in the tank.  And squeals like a pig when it does release?  Especially when bike sits in the sun?  You know where I'm going with this.  So don't ask.  Just think thru it.

Bob

[grumpyguzzi]

grumpy -- some not too bad news and some probably bad news.

First, the oil sensor is checked once when the ignition is first turned on (must be 0 ohms) and checked continuously when running (must be something non-zero).

The oil sensor is a fairly common part you can buy at Napa, etc.  The key determinant is the electrical connector. I used this for my 2012 Norge: https://www.napaonline.com/en/p/ECHOP6144?interchange=1  Easy to replace.  Access is terrible.  It will take longer than you expect.  You will get intimate with your Norge.  I used pipe sealant even though MG says don't.  USE A TORQUE WRENCH or you could be left with a leak: loose threads or stripped threads.
Here's some helpful articles:

https://wildguzzi.com/forum/index.php?topic=77673.0

https://wildguzzi.com/forum/index.php?topic=84048.0

http://blog.road2ride.com/search?updated-min=2015-01-01T00:00:00-05:00&updated-max=2016-01-01T00:00:00-05:00&max-results=10

http://blog.road2ride.com/2016/01/

Now the probably bad news.  Your oil pressure problem could be caused by a failing sump gasket.  Sometimes the oil galley surrounds get a bit weak and lose pressure.  More likely for the 8V.  Easier access than oil pressure switch.  But there are surprises.  Spend some time researching first.

Thanks Bert! I'm already way more intimate with this thing than I ever want to be  and I own 3 torque wrenches. I'm pschycing myself up to tackle it.

[grumpyguzzi]

for what it's worth, when the plastic tank on my 97 Buell began to bubble, I had it stripped and repainted.  The painter first used an epoxy based primer in an effort to "seal" the tank from the gas vapors that leach through, causing the bubbles.  That was at least 12 years ago and not a bubble or paint flaw since.

Sounds like that's worth a try. I have to do some refinish work on the left bag and a little on the fairing to deal with some road rash from the previous owner.