Just inherited a 1975 xs650

[ThatXS650Guy]

75 is my favorite XS650, nice bike. Be aware that vinegar and evapo rust will not touch varnished gasoline. So if you have a layer of varnish in the tank the evaporust will not neutralize the rust under the varnish. You need to get all the varnish out with acetone or some other solvent before can use vinegar or evaporust. I found this out the hard way.

Acetone will also remove that beautiful, sexy Yamaha paint scheme. Get yourself some mold release to protect the paint before you let acetone get anywhere near that tank.
https://www.aircraftspruce.com/catalog/cmpages/moldplastiease.php?clickkey=11425
Caswell sells something similar in a smaller quantity.

 

[Mikey]

Nice looking 75 especially with the windjammer
I'm jealous
Welcome to the forum

 

[Santa]

Hey all! Long time no post, as they say, life uh... gets in the way - Jurassic park or smth I don't watch movies.
First thanks for all the kind words and helpful comments! I took a look at the checklist for the condition of your find, that GLJ recommended and the bike seems like the perfect fixer-upper.

Since last time I got some petcock and carburetor rebuild kits for obvious reasons, opened up the petcocks, and I got to see the best 1/4 inch layer of old gas gunk I've seen in a while. It came with some "fresh" gas too as you can see.


On another interesting note, the tank has the '71-'74 two-hole petcocks though I know it's never been modified. I thought it would be the newer three-hole style, am I wrong or is there something else I'm missing?


After Disassembly:

I went on a fun trip all around town looking for kerosene out of season to try and clean these. after a couple of hours and a couple of too many stores I ended up just deciding on carb cleaner and good old elbow grease.

With just a little bit of work, I was able to pull out most of the gunk to get this:

With a little bit of carb cleaner and some work got some nice new-looking petcocks!



Also as you might remember I was taking the rust out of the gas tank. I have finished that but there's this layer of gunk that coats everything now. I can kind of wash it off with a hose but I want a little more power than that to get the rest of it. I was thinking of taking the tank to a self-serve car wash and spraying it out before reattaching the petcocks. I'm just a little torn on how reckless of an idea that may be, let me know what you guys think or if you have a better idea, I'm all ears!


After that are the carburetors. Hopefully, it's as easy as these to clean and then we keep on moving through the oil system and try to run it for the first time!

 

[MaxPete]

Well Santa - it looks like you've got yourself a ballgame there!

Pete

 

[X77S]

I wouldn't spray the tank out at the car wash. I'm not sure the best option, but I'd think it would flash rust right back.

 

[Santa]

I'd think it would flash rust right back.

My plan was to spray it and then immediately add gas to the tank to keep the rust off, a pseudo oil coating if you will

 

[gggGary]

Ethanol gasoline is a pretty good solvent.
I'm running this Honda now after tri sodium phosphate and hot water (a 110 volt water heater element) then electrolysis. Dried with a hair drier and sunshine, chain in it, shake, blow out rust with compressed air, put in gas and started riding. It was pretty bad.
before

after

The gas gauge even works!

 

[RustiePyles]

Hey all! Long time no post, as they say, life uh... gets in the way - Jurassic park or smth I don't watch movies.
First thanks for all the kind words and helpful comments! I took a look at the checklist for the condition of your find, that GLJ recommended and the bike seems like the perfect fixer-upper.

Since last time I got some petcock and carburetor rebuild kits for obvious reasons, opened up the petcocks, and I got to see the best 1/4 inch layer of old gas gunk I've seen in a while. It came with some "fresh" gas too as you can see.
View attachment 193377

On another interesting note, the tank has the '71-'74 two-hole petcocks though I know it's never been modified. I thought it would be the newer three-hole style, am I wrong or is there something else I'm missing?
View attachment 193378

After Disassembly:
View attachment 193379
I went on a fun trip all around town looking for kerosene out of season to try and clean these. after a couple of hours and a couple of too many stores I ended up just deciding on carb cleaner and good old elbow grease.

With just a little bit of work, I was able to pull out most of the gunk to get this:
View attachment 193380
With a little bit of carb cleaner and some work got some nice new-looking petcocks!
View attachment 193381
View attachment 193382

Also as you might remember I was taking the rust out of the gas tank. I have finished that but there's this layer of gunk that coats everything now. I can kind of wash it off with a hose but I want a little more power than that to get the rest of it. I was thinking of taking the tank to a self-serve car wash and spraying it out before reattaching the petcocks. I'm just a little torn on how reckless of an idea that may be, let me know what you guys think or if you have a better idea, I'm all ears!
View attachment 193383

After that are the carburetors. Hopefully, it's as easy as these to clean and then we keep on moving through the oil system and try to run it for the first time!

What have you done to the tank all ready? I had to rinse mine with very hot hot water several times (after acetone & vinegar) and de-scale it with some chain to get all the gunk out. I used Marvel mystery oil to coat the tank before adding fuel.

 

[59Tebo]

Hi Santa. When you go through your carbs, go ahead and replace every piece of fuel line. Today's gasoline contains ethanol (bad for gaskets and fuel lines). Tygon is a good choice for fuel lines, since it's pretty much impervious to ethanol. You're better off using non-ethanol high-test. Good luck!

 

[Santa]

What have you done to the tank all ready?

It came with 40yo gas in it so after dumping that I used vinegar to get most of the big chunks out and to try to get the rest of the old gas, then I used a gallon of evaporust on rotation throughout the tank. That got most of the rust but now it's just leaving like a layer of sediment/gunk that needs some force to remove and I can't figure out how to apply elbow grease to somewhere I can't fit my hands.

 

[fredintoon]

75 is my favorite XS650, nice bike. Be aware that vinegar and evapo rust will not touch varnished gasoline. So if you have a layer of varnish in the tank the evaporust will not neutralize the rust under the varnish. You need to get all the varnish out with acetone or some other solvent before can use vinegar or evaporust. I found this out the hard way.

Hi Rustie
negative acetone! It'll wash the paint off the tank's exterior if it spills there.
What I do to clean out crudded-up tanks is remove the gas taps, plate over the tap holes, pour in a half-gallon of kerosene or diesel fuel, drop in maybe a yard of dog leash chain, snap the tank filler cap closed and give the tank a half-hour ride on a rail that's turned by a BBQ rotisserie.
Some folks use a fistful of nuts & bolts instead of a chain but they can be difficult to remove.

 

[MaxPete]

We have a guy in our local CVMG section who built a tank turner (think of a portable cement mixer) - he puts a small bag of aquarium gravel and a couple of quarts of plain water in the tank and seals it up with a winemaker's cork.

24 hours later....clean as a whistle.

 

[RustiePyles]

Hi Rustie
negative acetone! It'll wash the paint off the tank's exterior if it spills there.
What I do to clean out crudded-up tanks is remove the gas taps, plate over the tap holes, pour in a half-gallon of kerosene or diesel fuel, drop in maybe a yard of dog leash chain, snap the tank filler cap closed and give the tank a half-hour ride on a rail that's turned by a BBQ rotisserie.
Some folks use a fistful of nuts & bolts instead of a chain but they can be difficult to remove.

Yes, acetone will remove the paint off the outside of the tank post hast, but so will gasoline.... And somehow we all manage to keep that off the outside of the tank. I've de-gunked several tanks with acetone and never hurt the paint on a single one, because I'm careful.

It came with 40yo gas in it so after dumping that I used vinegar to get most of the big chunks out and to try to get the rest of the old gas, then I used a gallon of evaporust on rotation throughout the tank. That got most of the rust but now it's just leaving like a layer of sediment/gunk that needs some force to remove and I can't figure out how to apply elbow grease to somewhere I can't fit my hands.

The stuff left in the bottom of your tank is the 40 year old gas turned to varnish, you need to get it out with some sort of solvent. You will find that under it is a bunch more rust that the vinegar didn't touch. You're gonna wave to do another vinegar treatment once you get the varnish out. Vinegar will not break up varnish and it will not convert rust under varnish.