I have the P-51 pts with the evo .46 engine that comes with it. I had a fellow flyer tell me I needed to take off that engine balancer that goes on the prop back plate to get rid of some of the rotating mass to give my engine more power. If you have not seen it, it is a metal ring that presses onto the outside of the prop back plate to smooth the engine out, and it does have some weight to it. I went ahead and took it off and after a few flights I really cant tell a difference as far as the engine spinning up more. It almost seems like it might be a little worse as far as running smoothly. My question is, for those that have experience with this engine. Did I mess up by taking this balancer off and would have been better just leaving it? I didnt mark it when I took it off so hopefully I can put it back on and still be balanced? thanks for the help.

Removing the flywheel won't hurt the engine, but it might make your idle a little less reliable at low RPMs. The flywheel doesn't "expend" any energy, rather it simple stores it, so it really doesn't affect the top RPM significantly. That means it takes a little longer to spool up when you punch the throttle, and will take a little longer to wind down with the weight on the engine. The biggest argument against it is that its really "non-working" weight on the plane. Just be careful that you don't screw up the CG when you remove it.

A far more effective means of improving the engines performance is scrapping the three bladed prop that comes stock with that airplane, and replacing it with a two bladed APC 11x5. Its not as scale looking, but makes a HUGE difference in performance.

Brad

bkdavy is right, I have the same engine , changed to a 11x6 2 blade APC prop and got 13.000 plus rpms with the flywheel on.
I switch between the flywheel or the spacer , it depends on what the airframe needs for balance.

Taking off the flywheel will not effect top RPM at all. It will effect how quickly the engine will accelerate and decelerate as well as idle smoothness will suffer. Most of the popular 2-blade spinners don't work well with the flywheel either without work. Basically your friend was wrong but removing it will allow you to change to a better prop/spinner which WILL help.

Thanks for the info. I am already runnig a 10x6 and it does pretty good. I think I will put the balancer back on so I wont have the idle problems. I am not good at flying it in for a landing yet as I am putting down the flaps and letting it idle in on a nice slow glide slope. Would hate to have the engine die on a missed approach.

The upside of the weight/flywheel ( it's not a "balancer" ) is that as BKDavy posted, it makes the engine idle far more reliably... something which is very good for a beginner.

The downside is that you often end up adding weight to the tail to offset this.

As you progress to the point where you've removed all of the training aids, you could/should pull off the nose weight/flywheel. Doing so means that you can then pull off any tail weights...

This dropped almost half a pound from my plane.

Just be warned. I bought a Dubro spinner to put on my EVO PTS but it doesn't fit very well without lots of mods. The optional prop driver that fits the EVO motor is too big to fit inside the hole in the back of the spinner backplate....You'l have to do a lot of carving on the back plate or try and reduce the diameter of the prop driver washer.

I used a Great Planes aluminum 2.75" spinner, which bolted right on with NO problems.