rusty tank

[asphaltwheelies]

hi fullas and maybe gals just wondering what is the best way to remove rust and shit from the inside of my 93 kdx200 2 stroke petrol tank?.. i have the oil injection system removed and i think the new to me tank has been sitting for a while with the gas cap detached .. maybe gun cleaning solvents will work ?

[OLHILLBILLY]

Rust? In a plastic tank? Oil injection on a KDX200? Whaa...

[asphaltwheelies]

its definitely a steel tank and I've been told i have a Japan import because of the smaller carb, steel tank etc.. great bike apart from the daym weak powervalve assembly

[asphaltwheelies]

i bought an 89 kdx200 for parts but i found out the hard way they have different tank, forks, carb etc.. and on my rideable kdx the chassis number has the last 2 numbers grinded off but pretty sure its 93

[asphaltwheelies]

and while were at it, is there any way to tell if my blue forks are off a kdx or kx250.. ive been told the blue forks are kx250 91-93? not sure and despite my user name here i do slay the trails here in NZ..

[OLHILLBILLY]

Little research and I found that the '90's metal tank bikes were the SR (street legal dual sport version) European KDXs. Also see that most folks s**t can the metal tanks, take the SR oil injection stuff off (as you have done), and use E model plastic tanks.

[asphaltwheelies]

cheers for the info mate i wilt have to look into the plastic tanks etc..

[OLHILLBILLY]

and while were at it, is there any way to tell if my blue forks are off a kdx or kx250.. ive been told the blue forks are kx250 91-93? not sure and despite my user name here i do slay the trails here in NZ..

93-94 KDX200 had the blue USD forks too. Believe the lower tubes were 41mm on the KDX 200 versions. 43mm on the KDX 250 and KX250. KDX versions don't have a rebound adjustment either.

[asphaltwheelies]

found out they are in fact kdx200 forks ..(thought so).thanks to you many times ol hill billy i couldn't have done it without you... wish i had some moon shine to shout ya lol ride on

[knudsen]

On the steely, just soak in vinegar a day or two. Flush the shit out of it once the rust is gone.

[motoxvet]

On the steely, just soak in vinegar a day or two. Flush the shit out of it once the rust is gone.

Then, immediately coat it with a little oil or it will flash rust overnight.  Forget about Kreem.  I got several kits for almost nothing and it turns out that's what they were worth.  You don't have to coat it with anything like Kreem.  It will be bare steel - just like from the factory.  Just don't duplicate the conditions that allowed it to rust in the first place.

[Jeekinz]

I use either oxalic acid by itself or mineral spirits with some sheet metal screws tossed in.  Give it a good shake.

[motoxvet]

I use either oxalic acid by itself or mineral spirits with some sheet metal screws tossed in.  Give it a good shake.

Where do you buy oxalic acid and do they have a common trade name for it?

[Jeekinz]

Where do you buy oxalic acid and do they have a common trade name for it?

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR10.TRC0.A0.H0.Xoxalic+acid&_nkw=oxalic+acid&_sacat=0

 

It's also sold as "wood bleach" to clean your deck, but I tried 4 hardware stores near me and didn't see it.  I just ordered off ebay.  Mix about 1/4 cup with 1 gallon of water.  

 

 

Edited October 7, 2014 by Jeekinz

[motoxvet]

Thanks!   How long did that pile of parts soak to work that well?  I suspect a really bad tank would take a while longer...?

[shrubitup]

Some paint thinner is similar to mineral spirits. Have used pennies before too instead of sheet metal screws but the screws are prolly more abrasive. ?

I suppose you could do final rinse with ATF due to high detergent properties. Then fill up with ethanol free gas mixed with two cycle oil at 32:1.

Pure-gas.org

Edited October 7, 2014 by shrubitup

[Jeekinz]

Thanks!   How long did that pile of parts soak to work that well?  I suspect a really bad tank would take a while longer...?

 

I think it was overnight.  You have to just play around, there's no real procedure that I know of.  But those are approx. measurements I use.

 

Shrub, chain (not motorcycle chain) works good too.  Worst one I did was on my KD100, there was a bad Kreem job with just some surface rust underneath.  I sloched around some chain and MEK to break down the Kreem, then finished off with the sheet metal screws and mineral spirits. Took hours.

[motoxvet]

A TT'er has mentioned he put the acid and hardware in the tank, wrapped his tank in bubble wrap and put it in the clothes dryer for a couple of hours.  Sounds good until something goes wrong - like the bubble wrap comes loose.

[Jeekinz]

Wow!  That's a new one.  lol