Noob question on motors
 

Hey I'm new to this so i have no idea what I'm doing but i recently got given a pureten gp alpha 3 4wd and i was told the engine was cooked in it and i needed a new one
any recommendations on what i should get or should i try and fix the one it's got
also ive got a manual for the amg merc but it has the wrc subaru shell on it. Its there a difference in that?
thanks

all nitro engines go bad, not uncommon for racers to replace them every 3+ gallons of fuel.

I don't run nitro so I can't make any recommendations on a specific engine, but I would only consider the brands of engines listed here if I were to buy a nitro for myself today:

https://www.top25rc.com/nitro-buggy

Another newbie question.... Will a xl5 traxxas esc and the 12T motor fit on a redcat volcano w/o heating up?

yes, but the key is proper gearing:

• What gearing for upgraded electronics?

If you already have the electronics great, but if you're buying them, I would recommend a mild brushless system instead:

running a 64spur and a 16T pinion.

Please read the article I linked which discusses the process to select proper gearing for a motor upgrade. Good Luck!