Generac — Test 33 – Check Valve Adjustment
Adjustments · Valve clearance
From a Generac service manual covering: GP1800, GP1850, GP3250, GP5000, GP5500, GP6500, GP7000, GP8000. Check it applies to your exact model before use.
Applies to: Generac GP1800, Generac GP3250, Generac GP5000, Generac GP5500, Generac GP6500, Generac GP7000, Generac GP8000, Generac OHVI engine
Before you start
- Use a new rocker arm cover gasket.
Procedure
- Adjust valve clearance with engine at room temperature.
- Position piston at TDC of compression stroke (both valves closed).
- Loosen the rocker arm jam nut.
- Turn pivot ball stud while checking clearance with a feeler gauge.
- Hold stud with allen wrench and tighten jam nut to specified torque with a crow's foot.
- Recheck valve clearance after tightening.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 189/206cc intake 0.0039 inch, exhaust 0.0059 inch
- 389cc FridayParts $23.59 0.006 ±0.0008 inch
- 410cc 0.003-0.005 inch
- Jam nut torque 389cc FridayParts $23.59 9-12 ft-lbs; 410cc 14.01 ft-lbs
Full service-parts list: Generac GP1800 →, Generac GP3250 →, Generac GP5000 →, Generac GP5500 →, Generac GP6500 →, Generac GP7000 →, Generac GP8000 →
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.