Generac — Timing Belt Installation
Repair & overhaul
From a Generac service manual covering: IM100G, IM80G, NP100G, NP80G. Check it applies to your exact model before use.
Browse Generac generators & specs →
Before you start
- The timing belt must be clean and free of oil and water. Do NOT bend the belt. Arrow on belt must point in normal direction of rotation.
Procedure
- Check that No. 1 cylinder is at TDC of its compression stroke. Align camshaft and crankshaft pulley marks.
- Install tensioner and return spring. Hook the return spring to its stopper.
- Slide the tensioner to the left and tighten the lock nut temporarily.
- Check that the water pump and tensioner pulleys rotate smoothly. Install the timing belt.
- Loosen the tensioner lock nut. With all spark plugs removed, rotate the camshaft pulley two full turns counterclockwise. Tighten the tensioner lock nut.
- Check belt tension; with 1.06-1.28 pounds force the belt should deflect about 0.08 inch (2mm).
- Tighten the tensioner lock nut to 11-12 foot-pounds (15-17 N-m).
Specs & values
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.