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74 Cota 247 Brown Sticky Goo In Carb/cylinder

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1974 Montesa Cota 247 21M12797. Last season, I had my first real problem since purchasing this bike in 1978. The idle started to

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Really? I was just kind of "grabbing at straws" with that idea out of complete frustration. What happens, does the resin start to break down and dissolve into the gas? Have you actually heard of this happening before? Is there anything I can do such as a Kreem type sealer/coating?

I have a couple cota's of the same vintage, and the tanks have all been treated with Caswell sealer.

Caswell Plating

I did not experience the brown goo problem, so i can't say if that is the problem. All of my montesa tanks were getting soft and leaking at the seams. Love the Caswell epoxy sealer, and have never heard of any problems with it (unlike kreem...)

This is indeed the same symptom as noted in the USCG study on alcohol induced(ethanol) fuels in boats! Beware!

I have not even been able to find non oxiginated fuel of late. Other than Avgas!

Hopefully this "sloshing " of the tanks with some type of resistant sealer will work long term, jury still out? :moon:

This is indeed the same symptom as noted in the USCG study on alcohol induced(ethanol) fuels in boats! Beware!

I have not even been able to find non oxiginated fuel of late. Other than Avgas!

Hopefully this "sloshing " of the tanks with some type of resistant sealer will work long term, jury still out? :moon:

There are multiple threads on this site and others about sealing tanks. Internet wisdom says Caswells (the only tank of mine that doesn't leak has this) over other brands.

I think Racing gas may not have ethanol.

I had that happen to a BSA with a fibre glass tank. The throttle slide hung up wide open while I was charging up a big hill.

There was green goop all over the inlet valve too!

I bought a steel tank for it and had no more trouble.

I have a couple cota's of the same vintage, and the tanks have all been treated with Caswell sealer.

Caswell Plating

I did not experience the brown goo problem, so i can't say if that is the problem. All of my montesa tanks were getting soft and leaking at the seams. Love the Caswell epoxy sealer, and have never heard of any problems with it (unlike kreem...)

An aquaintance that restores vintage fiberglass (http://www.edsbultaco.com/index_files/Page344.htm) warned me that the Caswell product was the ONLY product that works on fiberglass. He developed a piece of equipment that keeps the tank rotating in all directions, while the epoxy cures. Apparently, that process and the Caswell sealer, does the trick as he guarantees his work.

Has the wife been putting sugar into the the tank to keep you at home more often??????

Has the wife been putting sugar into the the tank to keep you at home more often??????

Most women dont know what sugar is ?

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