Well i put my new 3.3 into my 4 tec from the 2.5 and the engine wont turn. It seems like the piston is getting syuck at TDC and is very hard to pull sometimes even with the plug out. Also it wont do it every time i pull the pullstart. If anyone can help me it would be much appreciated.

try checking for bindings near the clutch on the motor if the motor is brand new its most likeley its somthing your did or are doing (not trying to be mean) but if there is nothing binding up or catching on it then call traxxas and tell them the prob they might get you a new motor if its there fault hope this helps

What it likely is, is just the fact that it's a new, tight engine. It's not all that uncommon a problem.
Here's what you do;
First, pull the glow plug and drop 1 or 2 drops of after-run-oil in. Then put the glow plug back in, snug it down and then back it off about 1 turn. Now take a hair dryer or heat gun and heat the engine up until it's very hot to the touch. While the engine is hot plug the exhaust and pull the pullstart until fuel just reaches the carb (not going into the carb - just till fuel reaches it). Now conect the glow plug and try to start the engine.
After you get through about 3 or 4 tanks of fuel the engine will have losened up enough that you won't need to preheat it anymore.

We tried putting a few drops of oil into the engine but it's a very inconsistent problem because i can pull the starter 5 times with no problem and then it will stick and to the point where i can barely get it to pull through. And other times it wil be every other stroke. And i had it at my lhs and he said he hasn't ever had one this bad.

ahh the same thing happned to me with my first .12 engine. because its new it will be tight after it breaks in it will become much more easier. when it gets stuck simply get a flathead screwdriver and flip the car over and use the screwdriver as a lever and turn the fly wheel, that will make it so you can turn the engine over.

some advice, once you have done that keep on trying to start it, once you start it dont stop until you have run a whole tank of fuel, once a tank is through keep on running it and it will eventually loosten up and be much eaiser to use. hope this helps

Thanks we were trying to get it to work for atleast half an hour yesterday and it just kept getting stuck to the point where we could barely even get it to pull through. Sometimes having to pull almost as hard as i could. Thats even with the plug out of the engine.

Ok got it started with the wd40 trick