gas fuel tank


Sustaining Member
I'm pretty sure that the annoying behavior of my A4 (stalling at mid throttle, then ok if nursed through) is bad fuel - and since I use only good fuel, it might be four decades of crud in the tank. So instead of replacing the engine (which is well maintained and actually runs fine except for the above problem) I'm going to try replacing the fuel tank. It's probably due anyway.

The original tank is Monel. But I can't seem to find a source of Monel tanks - only plastic, aluminum, and stainless. Anyone know a source? (or does it have to be custom made).


Bill Sanborn

Member III
FWIW I would try running the A4 from a different source of known good fuel, maybe a gallon jug hooked to the fuel pump or siphoned directly to the carb.

You could also have a partially plugged exhaust system. Unfortunately taking it apart to check requires replacement of the system.

Monel is expensive. How about having the fuel polisihed? How are your fuel filters? Water seperating?

Good luck.


Sustaining Member

I replace filters regularly - and the problems occur even when they are new. Polishing I think will is less economical than a new tank.

Testing from a known clean source is a good idea - will try it.

I don't have a separate water filter - is that recommended?



Innocent Bystander
Even if it is the stuff in the tank you're going to want to keep the tank itself. You won't find a better tank material than Monel.

Bill's suggestion of an exhaust blockage is a distinct possibility. The situation sounds more to me like a fuel pump problem than bad fuel, especially if you're being good with the filtering, but perhaps that's my impression because I've never had an exhaust blockage on my A4. It could also be a bad condenser, worn cap or rotor, old spark plug wires, gummed-up carb, and probably several other things.

Have you checked out the forums?