Hello, im new to the whole nitro r/c thing and i just got a CEN ATX a few months ago and i was wondering what would be a good engine to upgrade to that wouldn't require too many changes? and are there any other upgrades you would recommend? thanks

Personally I would stick with the stock engine. Maybe convert to bump start and get a tuned pipe for it. Doing this will increase the performance for much less than buying a new motor. Another mod that worked well for me was to cut the exhaust header to match the outlet on the side of the engine. It is a very simple mod to do but it will increase the rev range and lower the running temperatures. Hope this helps.

os.18 cv-rx with a rotary carb will drop straight in the atx.