I had leaking problems with my evader. [:'(] I looked everywhere and finally saw that it was my exhaust header that was leaking. So i took alot of epoxy and covered that sucker and never had any more problems.
I also suspected the tank because lots of people have been having problems with their evader tank. SO i bought the rc10 gt tank and that helped too. The new tank looks much better. No leaks at all. And it gives a better pressure and fuel feed into the engine. That in turn made my engine easier to tune and more reliable. I can start in in 1 or 2 pulls now

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If you cant find the problem i would first try to just replace the tank. I would say you'll have to later on anyway. You just have to drill 3 new holes for the chassis. If you need help just PM me.
Hope this helped,
rc driver49