so ive been out of the hobby for a few years but i am just getting back into it somewhat. ive got a nitro rustler with an OS .15 CVX which for whatever reason i could never get to run right. thought i did the break in procedure correct but who knows, maybe something went wrong. Just cant get it to stay idling through a hole tank, maybe fuel is old at this point or something.

Anyway maybe just the motor isnt good and i should pick up a new one. I still have my original trx pro .15 which i could trade into traxxas for the 3.3 or i could pick up an OS .18. Which one would be recommended or what do you think could cause my isses of this one not running well. I gotta keep the idle screw WAY open to keep this thing idling decently. and i put the needles all back to factory settings for the time being.

or ill just re-abandon my nitro and go back to the mini-electrics that i used to have fun with before selling them

I have just got back into the hobby after a year or so, and when i tryed to get my Nitro mt2 started, it started and when i gave it any throttle it would cut out dead. And when i would pick up the car to inspect it, there would be lots of fuel run out of the exhaust. A trip to the local hobby store, and 2 litres of fuel later, i runs like a charm, former glory. I would recomend getting new fuel before you start to run any cars again. Hope this helped.

My first guess would be your far too rich.  Get new fuel, put idle setting back to normal, and lean the lsn until you get it to fire and idle....then tune following one of the many tuning guides.</p>

what is everyones favorite fuel? im placing an order through tower and could just throw that into my cart

Byron's 20% is the preferred fuel of racers. Bashers use just about anything that says NITRO on it.<div></div><div>As far as the two engines, 3.3 or OS .18, I would recommend going with the OS. In the long run it'll hold up much better and is more consistent in holding a tune. Also, if you get a brand new motor, the best method, IMO, to break-in the engine is by heat cycling it. A proper break-in doesn't need aggressive movement of the piston. Keep the temps at about 200 degrees F for the first 4-5 tanks and remember to cool the engine in BDC between tanks for 10-15 minutes.</div><div></div><div>Hope this helps!</div>