Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

> It's new. Shouldn't it be lapped and ready to go?

Yes, it should be, but don't bet on it. QC varies in model engine land.


The problem could be something simple like a bit of trapped swarf or a burr.  If not....

Because the valves are quite tiny, they need fine abrasives.  Things I've used that work at varying levels of efficiency are toothpaste, tin oxide, and bathroom cleanser.  I've had good results with SoftScrub.

Apply just a small amount, you don't want the abrasive to get onto the valve stem and into the valve guide. Check frequently, rinse and repeat until you get a clean seat.


Re: Running too fast

Use softer springs on the governor weights.  With the OEM springs, using a single spring will help a bit.