In my junk I use a Jeffrey tray (copy of the DC tray) and a scraper. Mr. Jeffrey told me he did not think the tray did much, but our little motors need all the help they can get.

I talked to Kevin (?) Johnson about the tray and he claimed his version of it was worth 17 horse, but would produce no proof.

I have run my motor with and without and never saw much difference. Our tray is just a lengthened copy of a small block tray.