help w/ electrical stuff and valve timing (1975 kz400)

i got a 75 kz400 a while back that wasn't running, and spent the last
4 months or so tearing it apart and putting it back together. i got
it running about two weeks ago, and took it out for a couple of
illegal spins around the block before i noticed that my (new) battery
wasn't recharging when it was running. i consulted my shop manual,
and it says i need to look into the regulator, rectifier, battery, or
dynamo.

the battery is good, and the recifier checked out. the field coil
was replaced by the prev owner w/ a new used part (he was dealing w/
the same problem), and i replaced the old regulator w/ a new used part
b/c the old one had had the cover removed and had rusted out. so,
that leaves me feeling it's probably the stator, but i'm not sure. (i
think) continuity was good between the 3 connections.

i found a post on the net about a guy w/ a cb700 having the same
problem as me, and he said he checked continuity on the 3 wye
connections and it was good, but that he was only seeing 4 volts or so
from each wire when it was running. i decided to try to do some
testing on the part tonight to see if i could see the same behavior
and know i needed a new stator.

the first thing i did was do the tests the manual suggested though.
i disconnected the 6 pin on the left side of the frame (under the
tank) and the 9 pin by the light to remove load from the dynamo. i
disconnected the recifier white plug and hooked it to my + lead on the
multimeter. i grounded the -. then i unplugged the green and brown
from the regulator and connected them together directly. doing so, i
noticed that i'd had those wires reversed by accident (the new
regulator i got was from a different year bike, and the color coding
was different tho the letters on the pins are the same as my old one).
i started the bike up and didn't see low voltage that the manual says
indicates a bad dynamo, but rather want to say i saw 18-25V (not sure
exactly, but it was higher than my reading of 13-14 on the battery
[note that my idle is high b/c i think my carbs are due for a
rebuild]). is this too high? anyway, i proceeded to unplug the 3
wire yellow 4 pin for the stator and tried to check for voltage coming
off of that, but got no reading w/ the - grounded or touching another
of the 3 pins. i think i had voltage coming through though because i
saw some spark a couple of times while doing the testing.

so if you've suffered through my verbose description, i bet you're
wondering where valve timing works into this. well, the prev owner
was over a week ago and he said the valves were tapping when the bike
was running, so he suggested we adjust them. he didn't remember how
to do it right, and we didn't find it in the manual, so we removed the
covers and unbolted the adjuster screws and adjusted them w/ the bike
running until the tapping was minimized. later i found the proper
procedure in the manual, and adjusted them "correctly" (going to tdc
on one side, adjusting to .10 mm gap, then rotating the crank 1 turn
to tdc and adjusting the other side). well, while the bike was
running during the electrical tests i'd noticed that one muffler was
much hotter and pushing more air than the other. the cool one was
burping flame occasionally as well. after about 15 min, i glanced at
the hot muffler and noticed the pipe near the engine had an orange
glow to it. so i turned off the lights, and sure enough the pipe was
glowing orange... i killed the engine at that point...

so... i'm left with a couple of questions that i hope you ppl can
help w/...

1) could the regulator green/brown reversed have been the source of
my discharging problem?
2) is there a proper way to check the stator wires for voltage?
3) how do i unbork my valve timings so i don't destroy my
engine/muffler? i noted in the manual that it said to always keep
the valve adjustment screw punch marks on the side of the +/-. i'm
almost positive we rotated them multiple times when we were messing w/
the timing initially. for the hot pipe, should intake/exhaust go + or
-? for the cold pipe that's belching fire on occasion, should it go
+/- , or is that sommething else (perhaps carbs)?

i love this bike and hope i haven't done it irreperable damage. i'd
like to track the electrical problem more (perhaps it wasn't running
long enough to notice a discharge, but i don't want to destroy it...
the bat is showing 13+ volts atm). the weather here has been great
and everyone who has a motorcycle has been out riding it, and i'd love
to be out w/ them, but there's work to be done obviously. if you can
provide assistance, it's much appriciated...

thanks,

-- john

 

I noticed today that oil seems to be leaking into the hot exhaust pipe
when it runs.

I'm debating whether or not to try adjusting the rockerarm screw '-' a
couple of turns, or if I should just take off the breather cover and
reset the camshaft and rocker arms.

No idea on the cool running pipe. Maybe the intake valve is off?

-- John

 

I noticed today that oil seems to be leaking into the hot exhaust pipe
when it runs.

I'm debating whether or not to try adjusting the rockerarm screw '-' a
couple of turns, or if I should just take off the breather cover and
reset the camshaft and rocker arms.

No idea on the cool running pipe. Maybe the intake valve is off?

-- John

 

Do what?

 

If I remove the breather cover, the camshaft has a gear w/ timing
marks on it. So you put the bike at TDC, put the camshaft back in so
a notch mark on the right side is pointing directly up, then move the
gear according to the timing marks, rotate the crank until the gear
bolt holes match back up w/ the shaft and reattach the gear and shaft.
Something along those lines, I was looking in the manual at it again
last night.

I donno. My left side is running too hot, and the right side too
cold. Spark plug conditions confirm that. I guess the side running
cold is probably my carbs, and I've got a new set on the way. The
left side m/b is running wrong b/c of carbs too (too lean?), but the
glowing exhaust pipe and oil makes me suspect that exhaust valve is
borked.

Last night I tried adjusting the rocker arm screw number of turns +,
but it made no visible diff to the position of the valve. I also
tried adjusting the screw on my carbs that controls syncro way in one
direction and then way in the other direction, but the hot side
continued to pump out a lot of hot air and the cool side put out a
little bit of relatively cool air.

If the hot/cold issue could be caused soley by the carbs, m/b I'll
wait on cracking the engine open until I get the new ones. If the hot
pipe is almost positively the exhaust valve not seating closed, then I
just need to open it up and take a look I guess.

To be honest I have no clue what I need to do, and seem to be venting
to usenet...

-- John

 

Well, yes, but the cam timing won't have anything to do with your
problem, so I'd leave it well alone.

 

I would've thought it related b/c cam timing moves rockers which move
valves... But I am new to all of this...

Where do you suggest I look to solve it? I just ran it for 30-60 sec
today to test the new tach I got. Right pipe was a little warm. Left
pipe was really hot. Do you think it's valves? Carbs?

If valves, should I just remove the breather cover and see if it's
seating? If not, then...?

tx for advice...

-- John

 

well, yes, it does, but it doesn't just go out of time unless something
catastrophic happens to the engine.

Carbs, sounds like. One may be running lean. Could be a burned out valve
- check the clearances - but my money is on carbs. Actually,
double-check the clearances. Early Z400s had an odd eccentric rocker
shaft system, I think, and it's possible the clearances are badly set.

You can't check for seating like that. You really need to remove the
cylinder head and I strongly recommend you don't.

 

ah, gotcha...

ok, i've got carbs in the mail, so i'll just be patient i guess... i
can redo the clearance. could running lean make it so hot that the
pipe turns orange?

well, if good carbs don't fix it, i'm guessing this is what i'll have
to do. i hope it's the carbs tho. i worry that when we adjusted the
valves while it was running we messed up that exhaust valve and the
seal has burnt out, or the stem warped, or something.

thanks much for your advice/help,

-- john