A little help, please .....long sorry

[Prez]

I recently acquired my 79 750E (7wks ago), I'm just now starting to get into the resto work. Also, I'm a diesel mechanic by trade, but no stranger to gas engines or bikes, although my trade makes me cringe at carbs 8-[. BTW, excuse me if I bounce around a bit a times......ADD's a real b*&%ch.

Anyway, I switched gears from the mechanical to cosmetic since I have another minor resto job, 91 Honda TRX 300 ATV that's @ 90%. The ATV only needs a good CDI and rust removal/ repair/repaint on the tank. Wanted the ATV done before winter so we could have it for use & playing around (best time to ride dirt & OR is winter,right?). Have access to most shop supplies & tools I'd need, but no exp in painting. My BIL has some left over clear coat from some body repair he recently did.

I was going to paint the ATV tank, then clear it. Due to trouble/cleanup with the clear and gun, decided it'd be best to do both at once. With winter & cooler temps looming, I'm feeling pressed to get it done ASAP.

Stripped both tanks down to metal today. I knew the both had some rust, but was in for a surprise. The GS has some serious rust around the emblem mounts on both sides, left side being the worst. Of course, I found a small hole on the left side, just beneath the rear of emblem mount.

My questions are......Is this tank similar to newer ones? Meaning the outside of the tank is merely a skin for aesthetic purposes only, or is it the outer retaining wall? If it's not a skin, how to go about sealing/repairing it?

Here are before shots, I'll take some after shots tomorrow with a good view of the hole.

[Ironriot]

BAH! I hate rust! Don't we all? But as for your question no these old tanks aren't like newer ones. They don't have an outer wall and an inner lining. So that hole you see is the same on the inside. I'd vote on getting a new tank. Unless you were good at body work. Then you could just cut out the rust hole and repatch it with some metal. But yeah if you do go the new tank route I'd recommend you Kreem the inside. Kreem is a tank liner made especially for this kinda thing. You could also use Por15. I've heard of people using that before

[Prez]

BAH! I hate rust! Don't we all? But as for your question no these old tanks aren't like newer ones. They don't have an outer wall and an inner lining. So that hole you see is the same on the inside. I'd vote on getting a new tank. Unless you were good at body work. Then you could just cut out the rust hole and repatch it with some metal. But yeah if you do go the new tank route I'd recommend you Kreem the inside. Kreem is a tank liner made especially for this kinda thing. You could also use Por15. I've heard of people using that before

Kinda figured that was going to be the reply. :-| Know about Kreem, never had an op to use it before though. The hole itself is rather small but, given the large coverage area of the rust, it's as bad or worse on the inside.

May be able to cut it out & replace. I'm not the best with welding or brazing, but my co-worker (the BIL) is. He recently brazed some patches on the muffler of my ATV, was some thin & rusted stuff too. Only prob with that is the emblem mount plates.

[Ironriot]

Kinda figured that was going to be the reply. :-| Know about Kreem, never had an op to use it before though. The hole itself is rather small but, given the large coverage area of the rust, it's as bad or worse on the inside.

May be able to cut it out & replace. I'm not the best with welding or brazing, but my co-worker (the BIL) is. He recently brazed some patches on the muffler of my ATV, was some thin & rusted stuff too. Only prob with that is the emblem mount plates.

Why not cut out the emblem mount plate entirely and clean up the look of the bike? That way you can just remove the whole rusted section

[MissFabulous]

Kreem is going to be a temp fix and can cause other problems down the road. From my research, the POR-15 treatment gets better reviews, but for lining a tank with pinholes, you can still run into some issues. With that kind of exterior rust, I doubt stripping it down from the outside any further would give you any good surface for an outer repair, but I think you already know this.

I'd vote for getting a new (used) tank which shouldn't be to expensive or hard to find if you watch ebay, check boneyards or post to the parts wanted section here. Might take some time and digging to get one, but shouldn't be impossible.

[Griffin]

You can probably find a serviceable tank on ebay fairly quickly, and get it for under $100. GS750 tanks pop up all the time.

[Griffin]

Is this off a 750? The seller doesn't know, but it looks to be in decent shape.

http://cgi.ebay.com/ebaymotors/SUZUKI-GS850-GS750-YEAR-MODEL-FUEL-TANK_W0QQcmdZViewItemQQcategoryZ35581QQihZ011QQitemZ320155947344QQrdZ1QQsspagenameZWD1V

[Prez]

Is this off a 750? The seller doesn't know, but it looks to be in decent shape.

http://cgi.ebay.com/ebaymotors/SUZUK...spagenameZWD1V

Thanks for the find. Have several that I'm watching already, somehow missed that one. I'll be sure to get some after strip/cleanup pics this evening, hopefully get some more opinions based on that.

Right now I'm thinking of getting an ebay tank for rolling rebuild or permanent replacement and kepping the original & trying my hand at the section removal repair.

PS Think all the 550-1000 tanks from that era are interchangeable, someone correct me if that's not the case.

Thanks for all the replies.....keep 'em coming. Hope I get this kind of response later in the week when I post ?s in the tech section .

[Ironriot]

You need to be careful. Some years/models have a different way of mounting. You should be able to tell just from looking at the pictures. Other than that basically they're all the same

[Prez]

You need to be careful. Some years/models have a different way of mounting. You should be able to tell just from looking at the pictures. Other than that basically they're all the same

Going to try to keep it in the same generation, and of course ask sellers for a specific length measurement, and underside pics, if they don't have them.

[Prez]

Here are the pics after stripping & rust removal.





You can see the right side was caught just in time, the left is another story.

[ironb12s]

Do a GOOGLE for tank liner or tank sealer, there are many, many of them out there now. Kreem is the bane of the Riders of Vision, we prefer the POR-15 or Caswell liners, and KBS is another popular 2-part epoxy. It's kinda like J-B in a pourable form, and will seal up those holes. You need to clean all of the rust out, and phosphoric acid is the chosen method, it will clean and etch the metal in prep for sealing.

Kreem degrades over time, to flake off or dissolve with certain fuel additives. Running with an inline filter is mandatory for any tank that is lined, more so for those that have been 'Kreemed'. If an ROV member finds Kreem in the tank, the first thing they do is remove it with acetone.

[Go Mifune]

When I first got my 77 gs750 It had a tank from a gs850 it fit fine but was in bad shape so I got one from a gs550. I put the 55O tank on but it did not fit properly, the bolt hole in the back did not line up with the nut so it fit slightly higher but I did kind of like the way it looked with a little larger space between the engine and the motor. I zip tied it down and used it for about a month until I got the correct tank. So yes some tanks are interchangable but many are not, just stay away from L model tanks.

[Prez]

Definitely only looking at E model tanks, and asking sellers of questionable ones for a measurement fron the rear mount to the rear of bushing cups.

Also, thanks ironb12s, I found some semi local dealers of KBS products.