Onan 6GO-F User Manual

MAINTENANCE AND REPAIR
Set the tappet clearances after the valves have been reassembled in
the engine. .When tightening the cylinder head nuts, start at the
center of the head· and work outward. and towards the . ends. After'
approximatelJ10 hours of operation, again check the tappet clear-
naces, making Strtneeessary adjustments.
IGNITION TDlING.- See Fig. G •. Set the distributor contact points to
0.020" gap at full separation. There are stamped markings on the fiy-
'Wheel 'Which can be seen by removing the small flJwheel inspection hole
cover on the right side of the engine. Tum the engine ov.er with the
hand crank until the No. 1 piston is cOllling up on the compression stroke.
Slowly crank the engine until. the fl¥wheel mark ION centers in the in-
spection hole. At this point, the distributcir rotor should point to the
distributor cap tower for the No. 1 spark plug wire, and the distributor
points should just separate. If the rotor points t~ the·tower for the
No.4 spark plug wire: it will be necessary to reniove the distributor,
lift the drive shatt in the cylinder head and tum it one hal£ tum.
start the plant and allow it to reach operating temperature. Test the
spark advanc~ by applying a full electrical load. Slow the engine by
pulling on the governor arm, then release and allow the engine to sud-
denly accelerate. There should be one or two "pings" or detonation
knocks. If no ping is heard, advance the timing. If a continuous ping
is present, retard the timing. Advance or retard the spark timing as
necessary by loosening the distributor clamp and turning the distribu-
tor body slightly clockwise to advance, or counterclockrdee to retard.
Retighten the clamp screw. Keep the spark advanced as far as possible
without causing a "ping", or detonation under normal running conditions.
PISTON RING REPLACEMENT.- The piston and connecting rod assemblies are
removed from the tops of the cylinders. Check the cylinders for out of
round, tapered or scored. condition~. Rebore for oversize pistons if nec-
essary. Any ridge worn at the top of the cylinder should be removed if'
not reboring.
Two eompressien rings and one oil control ring are used on each piston.
Fit eaeh ring to its individual cylinder, checking the gap- bet\veen the·
ring ends by plaCing the, ring squarely in the cylinder in a position
correspending to the bottom of its travel. Se.e Fig. H. The correct
gap is from 0.008 to 0.013". Do not use rings 'Which require too much
filing to obj;a,in the correct gap •. If using the old pistons, clean all
. ring grooves of carbon deposits and see that oil return holes are open.
See that eaoh ring fits its groove properly, with 0 •. 0015" to 0.002"
c1earanee •. R:1.ngs of the tapered type will be marked "'IDP" or may be
otherwise easily identified •. and this taper must be installed with the
smaller diameter toward the clOSed end of the piston •. Fit th!:l proper
ring in each ring groove on the piston, spacing the gaps equally around
the cireum1'erence of the piston. and no gap directlJ in line with the
piston pin.
. . . . .
PISTQNREPLACDmNT.- U'cylinders b~eome badly worn, tapered or scored,
rebore and hone to f1tone ·of tqe available oversizes in pistons. Pis-
tons are available. in .010ft, .020", .• 030", .040". .0';0" and .060" over-
sizes. The pistons should be fitted to the cylinders to a clearance of
.0015" measured vdth' a 1/2" mde feeler gauge inserted between the pis,- .
ton and cylinder at a point half way between piston pin holes. A pull ,
of 5 to 10 pounds should be required to pull the feeler gauge past the ..
piston. See Fig. I. Piston and connecting rod assemblies must be ,prO;'
perly aligned before instal1atio
ll
in the engine. ' .
. 23

Onan 6GO-F Specifications

General

Brand	Onan
Model	6GO-F
Category	Inverter
Language	English