Any adjustments to a jet pump's performance usually involve:
* Replacing worn parts: If the pump isn't performing optimally, the problem likely lies in worn impellers, wear rings, or other internal components that require replacement, not shimming. These parts are precisely manufactured and simply need to be replaced with new OEM or equivalent parts.
* Alignment issues: Misalignment of the jet pump housing with the drive shaft can affect performance. This is addressed by precise alignment procedures, not by adding shims. Shims might be used in the *mounting* of the entire jet pump assembly to the hull, but this is a broader structural adjustment and not related to the jet pump itself.
* Adjustments (rare and specific to the model): Some very specific jet pump models might have very minor adjustments possible, but this is highly model-dependent and would be outlined in a workshop manual specific to that pump. It would almost certainly not involve shims in the traditional sense.
In summary, if you're experiencing jet pump issues, the solution is rarely "shimming." Instead, you should consult a service manual specific to your jet pump model or a qualified mechanic. Improper adjustments can lead to damage to the pump and other related components.
