What to Do About My Tank

[D0wn5h1ft]

I have a decision to make about the tank of my '79F. Right now I have the original tank on it. I'm not really concerned about the paint because I'm going to strip it and repaint anyways. The problem is, however, that it's got this big a$$ dent in the side of it and I don't think it's something I can pull without spending big bucks to get it fixed.


Said dent:



When I got the tank the gas only came up about to where it top of the U-bend is in the tank so everything above that was all kinds of rusty. I spent over $60 on rust remover products to get it to a usable state and it's still not great. Now it seems like there might be a tiny (very tiny) pinhole leak along the right hand side seam but I can't be sure because it is so close to where the petcock meets the tank and it might just be a bad gasket. I could buy a tank liner and use that and it would fix most of my problems expect for the hideous dent in the side.

Needless to say I've got to make a call about this tank. I have a post in the wanted section for a new tank but I know good ones are few and far between (again not taking paint into account). There's this one on ebay that I want to buy but I wanted to get opinions first.

http://www.ebay.com/itm/80-81-Yamaha...0ccf84&vxp=mtr

Will a MNS tank even fit on my '79F?

[skids]

You could try using a dent puller followed by brazing the holes from the dent puller, then line it.

I had bad problems with a bike where I used bondo followed by tank liner...the chemistry doesn't agree and I got goop on the intake valves which became harder than the hubs of hell. I did have quite a few holes from the puller. I had to remove the head and I could not scrape that stuff off of the valve stems.

I have used epoxy with fiberglass mixed in to smooth-over the places where "Yamaha" attaches (older tank) for a smooth paint job and then bondo-ed over that for a smooth surface. Epoxy is very hard and difficult to sand, so you do not want that level too high (make it a little less than final surface). This has held up for years and I thank Denny Zander for the recommendation.

[D0wn5h1ft]

[QUOTE=skids;431555]You could try using a dent puller followed by brazing the holes from the dent puller, then line it./QUOTE]

That might work out ok. How hard it is to pull dents?

Also, do you know off the top of your head if a MNS tank will fit a standard frame?

[Petersg_99]

If it helps, I've got a standard bike and it's wearing a special tank.

[rdmcguy]

creased tanks

I have a tank with a similar crease in it ,
I took it to a body shop and they mentioned a technique that involves tack welding a Specialised (can't remember the name of it)piece of metal in strategic locations,and pull the whole dent out followed by removal of said metal ,grind the tack welds off light bondo, prime and paint no holes to repair
unfortunately mine is too rusty to salvage,good luck with yours

[Schming]

[QUOTE=D0wn5h1ft;431570]

You could try using a dent puller followed by brazing the holes from the dent puller, then line it./QUOTE]

That might work out ok. How hard it is to pull dents?

Also, do you know off the top of your head if a MNS tank will fit a standard frame?

You can have studs welded to the tank and pull the dents out also.

check out autobodystore.com for more info.

[LoHo]

I pushed out my dent with a curved piece of rebar and a mallet. I can post a pic or two if anyone is interested.

[DGXSER]

All good advice to save your tank.

Yes, the MNS tank will fit your standard frame. The tank and seat will not fit well though. And tour losing a couple gallons of fuel capacity as well.

[mharrington]

At least talk to a body shop- for them to weld studs on with a Uni Spotter and pull the dent MOSTLY out would be easy- not free but a simple job for them. You would simply have a much smaller blemish to fill with bondo. Just make sure the tank is free from all the flammable fumes for the body guy. (Even better if you can find a bodyman to do this on the side) I believe fiberglass on the exterior to patch rust and pinholes with a liner on the interior should be compatible and long lasting.

I remove rust from inside my tanks by putting a couple hand fulls of drywall screws in the tank. I then use rubber sheets and duct tape to seal of all openings. Then I wipe down the tank nice and clean- wrap it in blanket and stuff it in the dryer. Pack it in centered with towels so the tank is not flopping around. Run it on a no heat cycle for HOWEVER LONG- like 20 minutes and the flaky stuff will be no more.

[BA80]

I pushed mine out as LoHo said but with a different improvised tool. You should be able to access it from the inside to push through the filler hole and the hole for the fuel level sensor. It'll still require some bondo work but it won't be so thick.

[fredintoon]

I have a decision to make about the tank of my '79F. Right now I have the original tank on it. I'm not really concerned about the paint because I'm going to strip it and repaint anyways. The problem is, however, that it's got this big a$$ dent in the side of it and I don't think it's something I can pull without spending big bucks to get it fixed.

When I got the tank the gas only came up about to where it top of the U-bend is in the tank so everything above that was all kinds of rusty. I spent over $60 on rust remover products to get it to a usable state and it's still not great. Now it seems like there might be a tiny (very tiny) pinhole leak along the right hand side seam but I can't be sure because it is so close to where the petcock meets the tank and it might just be a bad gasket. I could buy a tank liner and use that and it would fix most of my problems expect for the hideous dent in the side.
Needless to say I've got to make a call about this tank. I have a post in the wanted section for a new tank but I know good ones are few and far between (again not taking paint into account). There's this one on ebay that I want to buy but I wanted to get opinions first.
Will a MNS tank even fit on my '79F?

Hi Gabe,
what bigass dent? All I see is a minor ding just to the rear of the Y in the tank badge.
If a dent is too big to bondo, here's the old-fashioned fix:-
Heat the area dull red and let it air-cool to anneal the steel.
Polish the bottom of the dent shiny clean and stick a 3/8" flat head screw on there with low temperature braze.
Thread a slide-hammer onto the screw and hammer the dent out.
Melt the screw off.
It won't be perfect so finish with a smear of bondo.
The Special tank in that link will fit right on but note that it's a gallon smaller.
The price is OK too so long as it don't leak and the gas cap, fuel taps and thermistor gas level sender shown in the link come with it.
None of those will swap with the stuff from your Standard tank.
A bonus is that the thermistor sender will work the red light in the Special tach on your bike.

[D0wn5h1ft]

Hi Gabe,
what bigass dent? All I see is a minor ding just to the rear of the Y in the tank badge.
If a dent is too big to bondo, here's the old-fashioned fix:-
Heat the area dull red and let it air-cool to anneal the steel.
Polish the bottom of the dent shiny clean and stick a 3/8" flat head screw on there with low temperature braze.
Thread a slide-hammer onto the screw and hammer the dent out.
Melt the screw off.
It won't be perfect so finish with a smear of bondo.
The Special tank in that link will fit right on but note that it's a gallon smaller.
The price is OK too so long as it don't leak and the gas cap, fuel taps and thermistor gas level sender shown in the link come with it.
None of those will swap with the stuff from your Standard tank.
A bonus is that the thermistor sender will work the red light in the Special tach on your bike.

Look below the yamaha badge. It's half a foot long. If you click on the picture it will let you zoom in on the tank.

[Schming]

Google, paintless dent repair for some more ideas.

[fredintoon]

Look below the yamaha badge. It's half a foot long. If you click on the picture it will let you zoom in on the tank.

Hi Gabe,
ooh, that dent. I mistook it for a shadow.
OK, that one, you need to fix.

[crazy steve]

Just fill it with bondo....

Bondo has a reputation for falling off if applied too thick, but that's only true if the panel is subjected to flexing (doors, hoods, etc) or if the prep is poor. That's not the case here; you won't have any flexing. Remove the paint and rough up the surface with sandblasting so the plastic can get a good 'grip' then apply enough on the first go to get it back to shape, then follow up to final finish. As long as the metal is oil and dust free for the initial application, it'll stick great. The metal on these tanks is pretty thin, you may just tear holes in it with studs to pull the dent.

You can try going in through the tank opening and see if you can get some of it out, but I wouldn't worry too much about it.