Cleaning And Inspection

Clean outside of cylinder head with a wire brush. Bead blast or scrape carbon from head, top of cylinder, top of bore above ring path, and inlet and exhaust valve ports. When scraping carbon, be careful to avoid scratching or nicking cylinder head and cylinder joint faces or bore. Blow off loosened carbon or dirt with compressed air.

Wash all parts in Harley-Davidson "Gunk Hydro-Seal." Blow out oil passages in head. Be sure they are free of sludge and carbon particles. Remove loosened carbon from valve head and stem with a wire wheel. Never use a file or other hardened tool that will scratch or nick valve. Polish valve stem with very fine emery cloth or steel wool. Check valve stem for excessive wear.

Valve head should have a seating surface about 1/16 in wide, it should be free of pit marks and burn spots. Exhausi valves should contain carbon that is black or dark brown. White or light buff carbon indicates excessive heat and burning.

Valve seats are also subject to wear, pitting and burning. They should be resurfaced whenever valves are refinished. Clean valve guides with an expansion reamer and check for wear and valve stem clearance.

Inspect spark plug port threads for damage. Replace Heli-coil (30, Figure 3-3) if necessary with special inserting tool If threads in head are damaged, a special plug type inseri can be installed using a standard spark plug port repair kit

Inspect valve springs for broken or discolored coils. Check free length or check tension of each spring. If a spring is more than 1/8 in. shorter than a new spring, or tension shows spring to be below low limit tension of new spring, replace it with a new spring. Check valve spring compression with valve spring tester against tolerances shown in "Engine Specifications."

Examine push rods, particularly the ball ends. Replace any rods that are bent, worn, discolored or broken. Check cup at end of rocker arm to make certain there are no chips broken out.

Blow out oil passages in rocker arms, rocker arm bearings and rocker arm covers.

If the rocker arm pads show uneven wear or pitting, dress on a grinder, maintaining original curve. If possible, compare with a new unit during this operation to ensure a correctly contoured surface.

Carefully check the rocker arm and shaft for wear. Replace rocker arm bushings if shaft is over .002 in. loose in bushings, as described in "Repairing Rocker Arms and Bearings."


To replace worn bushings (19), press or drive them from the rocker arm. If bushing is difficult to remove, insert a 5/8-11 tap into bushing. From opposite side of rocker arm, drive out bushing and tap. Press replacement bushing into rocker arm, flush with arm end, oil hole correctly aligned and split portion of bushing towards top of arm. Using remaining old bushing as a pilot, line ream new bushing Harley-Davidson Reamer Tool, Part No. 94804-57. Repeat for other end of rocker arm. When reassembling Vocker arm housing, install new 0-rings (18).

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