What is really at hand in the OP's question is the fact that not enough oil was used in a bushed engine. LA's and their older siblings FP's are bushed, they need castor. Castor is king with ringed and bushed engines, yet there are a lot of people that cannot understand it or are just ignorant of it's need.
LA's should run on 22 to 24% oil total by volume, half castor, half synthetic. My son has an LA40 that was given to him, he flies the heck out of it, I just dumped 4 oz of castor in a gallon for it.
No problems, stock plastic backplate with remote needle.
Chris...