Athena, head and base gasket. Type 'A'

3.5" inside diameter. Includes head and base gaskets to service one motorcycle.
With 0.040" thick copper head gaskets (91.5mm diameter) and 'A' style (late style) aluminium base gaskets, 0.012" thick (94mm diameter).
OEM replacement reference 16773-85 and 16770-84D for head gaskets, and 16774-84A for 'A' style base gaskets.
Explanation of 'type A' (early style) and 'type B' (late style) gaskets: There are 2 types of cylinder base gaskets available for Evolution models. For convenience, we will call them 'type A' (early) and 'type B' (late). The 'type A' gasket was introduced on the 1984 Evolution Big Twin models and can be used on all 84-99 Evo 1340cc models, fitting the contours of the cylinder base perfectly. They fit 86-22 Evo XL models, but protrude at the cylinder base. This can be a problem with silicone-beaded base gaskets. The 'type B' gasket was introduced on the Evolution XL Sportster models in 1986 and fits all Evo XL models as well as all 84-99 Evo 1340cc models, although the Big Twin cylinder base is slightly larger than the gasket. 'Type B' is the only type of gasket 'The Factory' supplied from 1986 onwards for both Evo Big Twin and Evo XL Sportster models. Both 'type A' and 'type B' have identical inner diameter, oil hole and bolt hole location. The gaskets for the front and rear cylinders are identical. The only difference between 'A' and 'B' gaskets is the outer perimeter.


Specifications


Brand
Athena


Application
84-99 Evo Big Twin (NU)


OEM
16773-85, 16770-84D, 16774-84A


Material
Copper


Packaging weight
0.136 kg


HS Code
84849000


Motorcycle family
BIG TWIN, DYNA, FX, FXR, SOFTAIL, TOURING


Original name
Athena, head & base gasket kit. Type 'A'