sticky gunk on amal slides

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Ron Callison

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Greetings everyone. Both slides at the air intake area were covered in a black, sticky, varnish-like substance that seized the slides in the bodies. I finally got the slides out and the stuff easily cleaned off with lacquer thinner, cleaned the bodies and everything is free again. Any ideas what the substance was? I use Chevron 91 fuel. Could Stabil cause this? Thanks for the help.

I have a picture but I can't see how to attach it.

Thanks in advance. Ron
 
When my original metal flake blue fiberglass fastback tank melted it deposited black resin into my carburettors as you described
It also started to jam up the inlet valve stems and I was losing compression
 
baz said:
When my original metal flake blue fiberglass fastback tank melted it deposited black resin into my carburettors as you described
It also started to jam up the inlet valve stems and I was losing compression
Click to expand...
I don't understand what you mean by "melted". What happened to the tank? Were you able to free up the valves?
 
I don't know about America but the petrol available in the UK melts fiberglass tanks fuel pipes carburettor O rings etc etc
I had to strip the head off,re lap the valves in
Clean all the crap out
And fit a steel tank, when I looked carefully at my tank I could see the sides were slightly concave where the top of the tank is gelled to the base
I'm lucky the whole lot didn't fall out with 3.5 gallons of petrol on a hot engine between my legs!
 
baz said:
I don't know about America but the petrol available in the UK melts fiberglass tanks fuel pipes carburettor O rings etc etc
I had to strip the head off,re lap the valves in
Clean all the crap out
And fit a steel tank, when I looked carefully at my tank I could see the sides were slightly concave where the top of the tank is gelled to the base
I'm lucky the whole lot didn't fall out with 3.5 gallons of petrol on a hot engine between my legs!
Click to expand...
Thank you for that Sir. I'll investigate the tank.
 
Steel or alloy tank would be a good move unless you can buy off road/recreational vehicle fuel.
 
I think it's fair to say than once the tank starts de-laminating/dissolving it's pretty much scrap.
Applying a lining compound is no longer an option either. Hang it on the garage wall like the rest of us :)
Replacing the tank with a steel or alloy one is pretty much the only long term solution, and what numerous folks on the forum have already done.
If your bike is a Roadster then good quality copies are available from EMGO. Fastback tanks aren't quite as straightforward, but can be found. I bought an Indian made tank in steel a few years ago and it was actually very good, but some are very poor.
 
RGM sell both types of Fastback tank made from Ethanol proof resin.

Martyn.
 
Why would the residue only be on the outer side of the slides? Surely if it was coming from the tank it would be further downstream?
 
cliffa said:
Why would the residue only be on the outer side of the slides? Surely if it was coming from the tank it would be further downstream?
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On my bike it was everywhere fuel vapour goes
But mainly it'd coated the inlet ports, valve guides,valves
The bike was losing performance I couldn't work out why until I took a float bowl off
Then all was revealed as I stripped the carbs off
This was the problem on my bike ,it may or may not be the problem on the original posters bike
Cheers
 
definitely worth whipping off the float bowls first I would say, but the tank will only be a matter of time.
 
AFAIK GP resin is gasoline PROOF. Old fashhion GP (general purpose) polyester resin is dissolved by ethanol, the glass fibers are immune to "E". I spent over 10 years trying to source a resin type material that resisted BOTH gasoline and ETHANOL. Only the novolac epoxy/vinylester resin sold (at the time) by Ashland chemical in Ohio, claimed to do the job. Two of the 3 blends were approved by the US coast guard for use with E-10 use in boats. Mainly for flame supression properties. I bought the 3rd generic type.
It was a process developed by another company then sold to Ashland , and now sold to a company in India :(
I do not believe in the long term protection of slosh type chemical linings. The resistance to gasoline and ethanol is NOT guaranteed in print by the manufacturing company. It is documented as ocassional contact ethanol"resistant" NOT ETHANOL PROOF.
novolac epoxy/vinylester resin is I believe what a very few tank makers use ( I have a 5 gallon pail to try it out)
 
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dynodave said:
AFAIK GP resin is gasoline PROOF. Old fashhion GP (general purpose) polyester resin is dissolved by ethanol. I spent over 10 years trying to source a resin type material that resisted BOTH gasoline and ETHANOL. Only the novolac epoxy/vinylester resin sold (at the time) by Ashland chemical in Ohio, claimed to do the job.
It was a process developed by another company then sold to Ashland , and now sold to a company in India :(
I do not believe in the long term protection of slosh type chemical linings. The resistance to gasoline and ethanol is NOT guaranteed in print by the manufacturing company. It is documented as ocassional contact ethanol"resistant" NOT ETHANOL PROOF.
novolac epoxy/vinylester resin is I believe what a very few tank makers use ( I have a 5 gallon pail to try it out)
Click to expand...

That's interesting, thanks for posting that information. I have 3 fiberglass tanks that have not "yet" been attacked by ethanol. I am really interested in what your testing shows, thanks in advance for sharing your results.

Has anyone else had any success lining a fiberglass tank?
 
Rod R said:
Has anyone else had any success lining a fiberglass tank?
Click to expand...
AFAIK all resin/epoxy linings seem to have a variable expiration date. So far, my belief is they all eventually fail for one reason or another. How many E-10 "resistant" not "proof", magic elixirs are "baked" in an oven as the chief chemist at Ashland chemical suggested to me as part of the process to insure a thorough reaction ?
All the stories of "well mine is OK" are only "as of today"?
 
One of our local Norton club guys was able to seal his Interstate tank by carefully cutting the bottom out, coating everything with Caswell's and then reattaching the bottom.
Fiberglass tanks only good for holding your ashes later on...
 
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