Old saw gas tank needs help. Refurbishing Poulan 4200 CounterVibe 69cc

[pen]

I recently was fortunate enough to inherit my grandfather's Poulan 4200. It had not run in about 15 years. He offered it to me 5 years ago or so, but couldn't take it insisting he still might need it!

Long story short, we lost Gramps last fall and I had a little time this summer so I've gone though the saw's carb with a new carb kit and gotten her running like a clock. Everything but the throttle lock is working as it should. The only problem is I can't get the fuel tank clean of rust to save my rear so I don't dare run it much.

I've been trying to clean it with gas or carb cleaner and toothbrush. Scrub, scrub, scrub, swoosh fuel around, strain fuel, repeat. I've done this to my wits end and I just can't get it clean.

Any suggestions on what I should be doing in here to get it cleaned out so it's not trashing this cleaned carb?

I've heard of "coatings" that can be put into the tank but have never tried any and don't know if that's the route that is appropriate for a magnesium tank or not.

As it is now, it's ready for fuel and can serve as a back up saw if I get myself pinched and need to cut out. Beyond that, I'm afraid all this rust will ruin the saw getting sucked through. This saw is rated to run a 16in to 36in bar. By sticking with 3/8 chain I can go up to 30in bar. The goal would be to get this tank cleaned up and have the saw fit for a bar larger than the current 16in,,,, if I can find one to fit.

Thanks for any and all help, here are a few pics of what I'm getting out of the tank on a piece of paper towel. Also of the saw and down in the tank as best I could get.

 

[festerw]

Maybe try some Evaporust? Works pretty well on the few things I've used it on.

 

[johneh]

Try taking it to a Rad and Gas tank Shop have
them clean it and seal the inside of the tank
Once a tank has rust it will always have rust
unless sealed If I remember correctly they use
an epoxy sealer and it works great on car and
truck tanks so why not a smaller tank .

 

[salecker]

This is what i do...
Take the tank off the saw,put a small handfull of small nuts and small screws into the gas tank after you have removed the gas line and filter. Then shake the piss out of the tank,switching where you hold it.When you think it has been shook enough, shake it some more.
Dump the stuff out of the tank and inspect,if it isn't clean repeat.
Here's a couple of pic's of one i did,it was severely corroded,came clean like it was new.
Shake it Baby,Shake it

 

[pen]

This is what i do...
Take the tank off the saw,put a small handfull of small nuts and small screws into the gas tank after you have removed the gas line and filter. Then shake the piss out of the tank,switching where you hold it.When you think it has been shook enough, shake it some more.
Dump the stuff out of the tank and inspect,if it isn't clean repeat.
Here's a couple of pic's of one i did,it was severely corroded,came clean like it was new.
Shake it Baby,Shake it

Thank for the advice! Did that today but used BB's and B12 chemtool fuel additive...... Worked like a champ. Went to town on the old girl and the film of fine chit even going though one of the permanent coffee filters, has been cleaned out.

It's pretty bad down there, still a few pieces of scale I can see but light years better than it was. Cut about a face cord of locust with the old girl today and have just a tiny bit of fuel left in her...... The cycle will continue until I finally get it clean as it should be.

Old girl is a light saber! Loving it!

Thank you,

pen