IGNITION TIMING

 CAN SOMEONE WALK ME THROUGH REPLACING TWO POINTS ON THE 78 YAMAHA
XS400?. THANKS IN ADVANCE

 

Unscrew mounting screws. Unscrew the little bolts that secure the wires
to the points. Carefully note the positions of the little fibre
insulating washers on the bits where the sires attach to the points, or
you'll short them out and then it will never work.

Reverse the procedure when installing new points.

--
BMW K1100LT  Ducati 750SS  Yamaha XT600E  Honda CB400F & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

 On Jun 29, 3:59 am, totallydeadmail...@yahoo.co.uk (The Older
Gentleman) wrote:

THANKS BUT CAN YOU TELL ME HOW TO SET POINTS GAP AND TIMING.

 

Oh, for fuck's sake, buy a manual.


--
BMW K1100LT  Ducati 750SS  Yamaha XT600E  Honda CB400F & SH50
chateau dot murray at idnet dot com
"What you're proposing to do will involve a lot of time
and hassle for no tangible benefit."

 On Jun 29, 8:55�am, chall...@hotmail.com wrote:


If noboody has ever messed around with the ignition timing, you can
just install your new points and gap them to .014 to .016 inches with
the points rubbing block on the HEEL of the ignition cam.

The cam is sort of egg-shaped, with a smaller diameter side and a
bigger diameter side. The heel of the cam is the smaller side.

The left hand (front) set of points is mounted on a large diameter
flat plate.

You set the ignition timing on the left hand points by loosening the
screws just a bit on the large plate and prying in the slot with a
screw driver and then tightening the screws holding the large plate.

If you have to move the large plate, that affects timing on the right
hand set of points and you have to loosen the screws holding the right
hand set of points and move that plate to compensate.

There are probably two marks on the flywheel on one end of the engine,
probably on the left hand side of the motorcycle.

They may be marked "F" for "fire" and "T" for "top dead center".

The spark plug is supposed to fire with the "F" lines up with a metal
pointer or a line scribed onto the crankcase.

You can turn turn on your ignition switch, and turn the engine over
with with a wrench. It's easier if you have the spark plugs out of the
engine.

Put an AM radio near the engine, tuned to a quiet spot on the dial.

When the ignition points just open, that's when the spark plug will
fire and you will hear a pop of static on the radio.

This is what is called "static" timing. ;-)

If you have a stroboscopic timing light, you can observe the full
retarded ignition timing (10 degrees BTDC @ 1200 RPM, and 36 degrees
BTDC @ 3100 RPM.