Generac — Positioning No.1 Cylinder Top Dead Center (Compression)
Adjustments · Engine
From a Generac service manual covering: CAC478, CAC480, SQR480. Check it applies to your exact model before use.
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Before you start
- Before rotation, spark plugs may be removed to reduce effort.
Procedure
- Remove two M6×55 flange-shaped bolts and remove upper timing gear cover.
- Install a wrench on the crankshaft pulley bolt and rotate crankshaft clockwise (viewed from pulley) to align TDC notch on pulley with TDC mark (0) on timing gear cover.
- Check whether the TDC mark on the camshaft gear aligns with the mark on the front end of the cylinder head.
- If not aligned, rotate the crankshaft one turn to align the marks; engine is then at No.1 cylinder TDC.
- With crankshaft pulley and lower timing gear removed, align TDC mark on crankshaft gear shaft with TDC mark on oil pump case.
Tools required
- Wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Source: Generac service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.