D-400 series engine muffler gasket and plate question.

[Phototone]

I have a Model 7084, with a D-400 type engine, bricktop. In looking at the parts diagrams on the Lawnboy parts website it appears that there is a sort of shield plate that is a separate part that goes between the gasket and the cylinder head. On my particular one, this was not present. The gasket is quite thick on this model. I ordered new gasket and plate for mine, as I am refurbishing it. Did they all have the shield plate, or was there a running change? It would seem its purpose is to shield the gasket from the head, and help form the gasket, help to keep its shape. Perhaps mine was disassembled at one time and when re-assembled the plate was forgotten?

 

[mechanic mark]

Parts and Diagrams for Lawn Boy 7084, Lawnmower, 1977 (SN 700000001-799999999)

 

[robinb66]

The plate is there too keep the gasket from malforming when mounting the mower and it's a good idea to have it!!