Aeon 350cc, Service Manual

Page: 66 / 192

ENGINE
4-66
◎ If the indicated seat contact is at the top edge of the valve
face and contacts the margin area(B) it is too high on the valve
face. Use the 30
∘
cutter to lower the valve seat.

◎
If too low use the 60
∘
or 75

∘
cutter to

raise the seat.
When contact area is centered on the valve face, measure seat
width.
◎
If the seat is too wide or uneven, use both top and bottom
cutters to narrow the seat.
◎
If the seat is too narrow, widen using
the 45
∘
cutter and re

-check contact point on the valve face
and seat width after each cut.
NOTE: When using an interference angle, the seat
contact point on the valve will be very narrow, and is
a normal condition. Look for an even and continuous
contact point on the black marker, all the way around
the valve face.
8. Clean all filings from the area with hot soapy water, rinse,
and dry with compressed air.
9. Lubricate the valve guides with clean engine oil, and apply
oil or water based lapping compound to the face of the valve.
Lapping is not required with an interference angle.
10. Insert the valve into its respective guide and lap using a
lapping tool or a section of fuel line connected to the valve
stem.
11. Rotate the valve rapidly back and forth until the cut sounds
smooth. Lift the valve slightly off of the seat, rotate 1/4 turn,
and repeat the lapping process. Do this four to five times until
the valve is fully seated, and repeat process for the other valve.
12. Clean cylinder head, valves, and camshaft oil supply
passages thoroughly.
13. Spray electrical contact cleaner into oil passages and dry
using compressed air.
CYLINDER HEAD ASSEMBLY
Wear eye protection during assembly.
NOTE: Assemble the valves one at a time to maintain
proper order.
1. Install new valve seals on valve guides.
2. Apply engine oil to valve guides and seats.
3. Coat valve stem with molybdenum disulfide grease.