Heat risers are notorious for not working properly. If yours is stuck, it will affect engine performance. Here is an inexpensive way to eliminate that problem, a non-functional spacer that is the correct size and shape.
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This valve is installed with the weight pointing downward. Picture shown in catalog is upside down from installation orientation.
The function of this valve was to keep the warm exhaust air in the manifolds for a longer period of time…
Stem diameter .3415", 5.070" long.
To determine the change level of your engine you need the original engine tag located under the water temperature sender.
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