Puch Fuel tank leaking

Hi,

Have a 1986 Maxi that had a rather rusty fuel tank when I bought it. At first I removed the petcock and with an empty tank and as piece if welding wire with a small loop in the end managed to fish out a bunch of rust. Kept flushing and felt I had gotten most of the loose stuff out. Then did an apple cider vinegar/salt flush letting it sit for several days. It looked much better so added a quart of rubbing alcohol to asorb the water and then blew it out with air till dry. Today I put in a new petcock and some gas and took it for a ride. Seem to run fine. Parked it and about an hour later I noticed a dark patch under the bike. It was gas and dripping a 2 drips a second. It seem to be coming from the very bottom of the tank near the weld. I drained the little gas that was left.

Now what to do. Is there an epoxy coating that I can put in the tank and slosh it around and seat up the leak?

Tom

Re: Puch Fuel tank leaking

Re: Puch Fuel tank leaking

Overpriced Parts /

Tom Hale Wrote:

-------------------------------------------------------

> Hi,

> Have a 1986 Maxi that had a rather rusty fuel tank

> when I bought it. At first I removed the petcock

> and with an empty tank and as piece if welding

> wire with a small loop in the end managed to fish

> out a bunch of rust. Kept flushing and felt I had

> gotten most of the loose stuff out. Then did an

> apple cider vinegar/salt flush letting it sit for

> several days. It looked much better so added a

> quart of rubbing alcohol to asorb the water and

> then blew it out with air till dry. Today I put in

> a new petcock and some gas and took it for a ride.

> Seem to run fine. Parked it and about an hour

> later I noticed a dark patch under the bike. It

> was gas and dripping a 2 drips a second. It seem

> to be coming from the very bottom of the tank near

> the weld. I drained the little gas that was left.

>

> Now what to do. Is there an epoxy coating that I

> can put in the tank and slosh it around and seat

> up the leak?

>

> Tom

Nope A new frame is needed.

That weld will just break when you ride the bike because it's weakened.

I had weakened frame just like yours crack on me and it wasn't fun. Post for a rust free maxi frame on buy sell is your best bet.

I got real nice one on my parts bike that has no rust/real nice inside the tank but It would take me a few weeks to strip, pack ship it with my knee not being healed up yet if you choose to buy it from me.

Re: Puch Fuel tank leaking

Steve,

Thank you for the link. I will give it some thought, it looks like a decent product.

Ken,

Thank you for the offer. I will do some more research and see what I can come up with. I hate to junk the frame if I don't have to. May try and braze it when I can definitely see where its coming from. It almost seems not cost effective get a new frame and have it painted and take the time to change everything over.

Tom

Re: Puch Fuel tank leaking

Double Trouble Dan /

rust blast msds is 10% phosphoric acid 2% zinc and the rest is water.

rust seal is Single Component Moisture Curing Polymeric Isocyanate.

basically polyurethane.

sounds expensive

Re: Puch Fuel tank leaking

Christian Bordelon /

For my SI we cleaned the tank with muriatic acid and then put epoxy primer (yellow) in the take, once the epoxy cured I drilled out the petcock hole and then reassembled the bike. Had to roll the bike around in every direction to get it to coat and removed the motor to let the excess drain out with no obstruction. my SI is doing great and holds gas with no problems.

Re: Puch Fuel tank leaking

Overpriced Parts /

Tom Hale Wrote:

-------------------------------------------------------

> Steve,

> Thank you for the link. I will give it some

> thought, it looks like a decent product.

>

> Ken,

> Thank you for the offer. I will do some more

> research and see what I can come up with. I hate

> to junk the frame if I don't have to. May try and

> braze it when I can definitely see where its

> coming from. It almost seems not cost effective

> get a new frame and have it painted and take the

> time to change everything over.

>

> Tom

Cost effective? No. No way is effective at this point.

You have a structurally damaged tank/frame. your life is not worth trying to save a rusted frame.

For you to braze it will still require disassembling it, still damage the paint and I don't know it just won't be perfect in my opinion.

Post for a frame of the color frame/forks swingarm you want or just change to the new color frame/bike .

Many times I took 2 bikes and made into one .

I've posted to buy/sell for a set of white forks and I had them in about a week.

Someone wanted a gold fender so I shipped one to him within about a week. Maxis are common color mopeds. I'm sure someone has the exact same color that you want.

I got blue and gray I'd part with but my red bike and white bike maxis are complete I can't part them out for the frames

It's just mopeds so you'll find another one

Re: Puch Fuel tank leaking

This maybe stupid but I'll throw it out there to get bashed on.

Would it be terribly hard to cut the frame and weld a tube in the tank kinda like a pinto but inside the frame? Then it should have a stronger frame and you could fix the hole?

I can't do these things but could it be done if you have the know how and tools? Cheaper than a new frame?

Its something I've been thinking of in case I run into the same issue

Re: Puch Fuel tank leaking

Maybe buy this after you weld a new piece where the tank was.http://www.lucky2strokes.com/ProductDetails.asp?ProductCode=jawa%5F210%5Ftank%5Fgrey

Re: Puch Fuel tank leaking

I'm saying can you weld in a new frame in then put the maxi frame over almost like a cover? You would lose tank room but wouldnt the fame be better supported? (edited)

Re: Puch Fuel tank leaking

Weld in a new piece and add a new separate tank. Loose the old tank.

Re: Puch Fuel tank leaking

The problem with just adding a new tank is that the frame is still weakened by the fact it has rusted through in a spot. It would be nice if someone did make a sleve or patch you could slide over the bottom area near the bend where most of the inside rust probably is. That could be welded and solve the problem. They do make a brace I've seem that goes from the neck at the top of the tank to the seat post area that should work I think.

Tom

Re: Puch Fuel tank leaking

I think you got it or replace the frame, is yours rusted or is your petcock just slow leaking, it can look like is leaking somewhere else.

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