So, I got a Losi xxx scb used from somebody and I noticed that when the throttle switch is set for pull = forward push= reverse, it cuts out at times, and the receiver also makes a nasty squeal. However if I reverse this, (push = forward, pull = reverse) it doesn't have either problems.

Also I'm hoping this is the proper place to post, thanks for any help.

Did you reset throttle endpoints when switching the direction? If not it's possible they are different and it doesn't get full throttle when reversed and the issue doesn't show up. Usually the first thing to try is adding a stutter stopper / glitch buster cap that plugs into any open slot in the receiver. Something like this or this.

A glitch buster on the rx should more than enough. Also try reversing the throttle channel on your radio.

Thanks guys, I'll pick one of those up. They look to be pretty handy even after I replace all my electronics.