Baseball Fan

I have a Zenoah G29 Extreme engine. I took the cylinder off and on the crank there is a resin like substance on the crank itself. I can’t post pictures until I have 10 posts. This resin is on both the bottom and top of the crank itself. Does anyone know what this is? Thanks for the help.

After further inspection, it appears that the engine builder cut out sections of the crank and filled them with this resin of sort to lighten the crank. I think…..