1975 r90 timing issue

[Jean]

(1) DO what Tim recommends for static timing. (I like to use a light, the one that came with the tool kit is easy to use. It has a gator-clip on one end and I can fasten the pointy end of the probe to any ground I can find with another clip)

(2) BOTH carbs probably needed a diaphragm. AGE does them in. They LOOK ok but they just ain't. Sluggish response.
There IS surely gunk in the port where the jet is broken off. Soaking alone is not enough to really clean them. You also have to remove the main jet "bushing" to clean that bore too. Run some FINE copper wire thru the little holes...a hair of copper from a flexible lamp cord is good for this.

[Foot]

Tim, hooked everything up, hit the ignition and light was on. That is with the base plate rotated counterclockwise to the max. If the adjustment slots were extended slightly the light would be out

[Deleted User 62]

Incorrect, turn the points plate clockwise to retard the timing and the light should go off. You did adjust the points gap to .016 when fully open, correct? All things being equal, the correct timing should be found when the points plate is adjusted to somewhere in the middle of the slot. Another thought; a friend was chasing a similar problem, turned out he had installed the points without their pivot pin mounted in the corresponding hole in the points plate. Worth checking. Are you using a Haynes or Clymer manual?

[Foot]

I got it wrong on the last post, the base plate was rotated clockwise to the max

[Foot]

Also the points were at 16 and I'm using a clymer manual

[Deleted User 62]

Points are adjusted when gap is largest, not when S mark is in window. Watch them as you turn rotor, and notice the bumps on the advance unit. Points gap is set to ".014"-.017" that's inches or ".35-.45 mm" not sure where you are getting "16" from...

[Jean]

I HOPE he meant 16 thousants INCHES.
Foot, FORGET the "S" for now.
What publishing date for the Clymer?
Is it a really BIG book or a smaller one with a Silver "frame" cover and an R75 with a Windjhammer faring in the picture?

[Foot]

Yes sir that's .016 point gap. Third edition third printing July 2006

[Jean]

The reason I asked about the manual you have is the numbers I quoted earlier for Dwell came out of a copy of an old woorshop manual (a real one!) that I have. The "new" Clymer manual says dwell should be 120 on the 1979 bikes and does not list dwell for earlier ones, BUT the way it's presented it sort of implies that is the dwell for earlier bikes too.

OK, back to setting timing. The "S" mark should show JUST at the moment when either the test light lights, or the buzzer sounds. The points won't be nearly as open as they need to be at this point. Once you rotate the Plate to get this to happen, tighten the plate-holding screws. Rotate the engine in the "running direction" using your allen key...THEN you set the gap when the cam pushes the points to their widest position. The "S" mark won't be in the window when you do this. We KNOW it's hard to crunch into this space...Big guys have more trouble.

[Foot]

Jean, I got my base plate at the midway point of adjustment. My points were set when at a high point on the shaft lobe at 38mm. Ignition on, rotate engine at rotor in clockwise direction the test light comes on just as the F dot mark appears