Must be doing something silly when settings timing or points

[deadram]

Hey all, just finished a top end rebuild (down to cleaning pistons/pin boss). Timing (points) looks all funny to me though.

When the bike is running, the bolt at the center of alternator cover should turn counter clockwise, correct? L Advance marks, LF, LT, almost 1/2 turn of crank, then R Advance marks, RF, RT.

Firing order should be left suck, and right blow - left squize, and right suck - left bang, and right squize - left blow, and right bang correct?

When looking from the left side ( ie, cager "drivers side") at the points the left side of the plate fire the left cylinder? In other words, the point towards the front of the bike, fires the spark plug towards the "road side", and the point towards the back of the bike fires the "curb side", correct?

LF mark is ~start~ of low Ohms on left points, right?

With cam chain tensioner installed correctly, the timing mark on cam points up to ceiling, when LT mark on alternator cover is reached, correct?

My left point turns off just after LF mark, and turn on way before hand, when turning bolt at the center of alternator cover (ie: crank) counter-clockwise. The points would have to be turned like 90' to fire correctly, and I'd have to move the grommet on points wire like an inch or two.

I've resealed the head twice already, rechecked cam timing (even with a staw in the piston, to make sure timing plate on alternator is set correctly), and I've read the manual for about 3 year span, and 6 or so models around that year. I must be doing something wrong.

P.S. Doing my 310T apprentiship, or my "Truck and Coach" for ontario, so I do know - a little bit - more then a backyard mechanic (no offence intended, if you are a backyard mechanic, that's how I started toward the 310T). I'm almost certain I've set everything right.

P.P.S. I don't have anything that fastens onto the frame plugged in, like condensers, power coils, battery, ect...

P.P.P.S. 1979 XS400, spoke wheels, drum brakes.

Thanks in advance, and like I said before, it has to be something silly I've overlooked, might try a test light instead of an ohm meter, if I can find it :/ but ohm meter jumps from full res to like 4-20ohms in a hair of a turn... stumped XD

 

[Liamthedevastator]

Hey, I just did my points and found it to be a relatively painless procedure. What is the condition of your points? Any pitting?

When turning over the engine to get the timing marks lined up you can only roll in the forward crank direction ie. ccw. if you slip past you'll have to go around again. Did you have a really good grip on the alt. bolt while it rotated?

 

[BBS360]

Yes, leftmost contact breaker is for left cylinder and the crank turns counter-clockwise.

My left point turns off just after LF mark, and turn on way before hand, when turning bolt at the center of alternator cover (ie: crank) counter-clockwise.

That is the correct operation. A spark plug fires when its contact breaker breaks/opens/turns off.
The contact closes before the fire mark in order to charge the coil before firing.

 

[BBS360]

I'm in the classroom part of my apprenticeship, and bored, so let me answer a bit more.

LF mark is ~start~ of low Ohms on left points, right?
...
ohm meter jumps from full res to like 4-20ohms in a hair of a turn... stumped XD

In a perfect world an ohm meter across the contact breaker would instantly go from 0 ohms to infinite ohms just as you go past the fire mark.
We're not actually needing to measure ohms herr though so I'd maybe switch to a timing light or just a continuity test.

With cam chain tensioner installed correctly, the timing mark on cam points up to ceiling, when LT mark on alternator cover is reached, correct?

That's correct. Might be more accurate to align the horizontal lines with the surface of the head. Easier to tell when they are parallel rather than the pip points "up".

I must be doing something wrong.

Sound like you have it pretty close. I'd get the timing right on the fire marks, attach everything to the frame, connect all the wires, and fire up the engine.

 

[deadram]

A spark plug fires when its contact breaker breaks/opens/turns off.

That's what I had wrong, had to turn the picture in my head 90', not the points Thanks bbs, and liam, should have her on the road by tomorrow, nice day out, so I'll probably drink too many beer to renew the plates today!

 

[drewpy]

I use a dwell meter to set points and a Xenon timing light to set the timing.

should be able to pick them up for a song as no-one uses them now

 

[Liamthedevastator]

nice day out, so I'll probably drink too many beer to renew the plates today!

As it should be. Carry on!