I noticed while putting my carb back on after sending it back to JustEngines.com for service, that there was a little drop of dried red paint right on the engine surface where the O ring sits on. I took a hobby knife and cut it off and it is totally smooth. Anyone putting their carbs on should make sure there is no paint build up on that surface so the O ring seals properly. It could cause an air leak and make the engine not run as good.

By the way, JustEngines.com has great customer service. Also that Irvine 53 is an awesome engine.

Joe