Rust in tank

[twotimeGSr]

Greetings.. I am getting ready to remove the carbs from my 79 gs850 because my #2 cyl is pretty non-functional. I pulled the #2 plug wire today and ran the engine... plenty of spark from the wire, did the same with #1 (runs good) and the spark strength is pretty equal... so I think the ignition is ok for now (or at least not the issue at hand). Anyway I am leaning towards a carb issue... but maybe a clog so I am looking for signs of rust.

I took a scope and looked in the gas tank. It has what appears to be light surface rust covering maybe 3-10% of the tank bottom with very slight possible pitting .. all on the top area of the bottom arch above the frame on the back half of the tank. No rust on the emblem areas or elsewhere. I don't think this would have clogged the carbs.. but I really don't know how it might disperse from the tank or accumulate in the carb.

How much rust is too much?

I had treated a badly rusted (flaking) tank on an Alfa Romeo Spider with POR-15 back in 2002.

Are there better and/or easier products than POR-15? and does anyone know how fast this rust might develop into a significant concern?

Thanks much,

tp

[Nessism]

There should be NO rust in the gas tank.

Tons of different threads in the archives about how to derust a tank. Search feature is your best friend.

[1948man]

Google up Caswell Coating. I used that and have had good results.

[twotimeGSr]

Lots of info.. many differing opinions amongst GS members! Caswell has a couple that might be very easy. I'll take my time and keep researching. Thanks guys!

tp

[1_v8_merc]

I've been running my 650 for years with some flash rust in the tank.
It was WAY worse when I first got it, so a little flash residue ain't that bad.
Usually it will slowly burn threw the system as you fill up the tank multiple times and ride a lot more.

I always run a secondary fuel filter, just incase something bigger gets in the line.

[twotimeGSr]

I know that rust is oxidation... but on a tank with little rust why would it begin rusting again after cleaned out? I assume... maybe incorrectly that mine started rusting from sitting so long and condensation occurred. Is there a coating from the factory that protects it when new but wears off after a period of time?

[Nessism]

No coating on the inside from new other than maybe a mild phosphate.

If your tank is just mildly rusted I suggest EvapoRust. Soak, rotate, soak, repeat until clean. It's good stuff.

[michplo]

Remove rust using electrolysis

I prefer to remove rust using electrolysis,make some search on the net and it has a tonne of info on that.My oncle did is tank last year's and it was amazing to saw wath was in that tank....il use that methode a lot a work to clean rusty tools car part's ect.. i hope it will help.. good luck.

Michel,

[frijoles-and-beans]

No coating on the inside from new other than maybe a mild phosphate.

If your tank is just mildly rusted I suggest EvapoRust. Soak, rotate, soak, repeat until clean. It's good stuff.

EvapoRust is really good stuff. I cleaned mine out a few months ago with the help of Cliff's tutorial about it. Look it up, because it's the way to go. I don't have a bit of rust in it right now.

[dieseln]

I've been using distilled vinegar for gas tank rust removal. I think I got the idea from this site. Gotta say - extremely happy with results. Vinegar is cheap and safe. 4 days soaking works miracles. Flush tank with the strongest water spray you have (i use a garden hose). Then spray interior of tank with a lib'ral dose of WD40 to prevent flashing. Just before you're ready to use the tank do a quick flush with a little gas.

[twotimeGSr]

What a great idea. It works great in the dishwasher too.

thx,

tp

[Guest]

What a great idea. It works great in the dishwasher too.

thx,

tp

Also works well in a coffee pot.