Topic: Valve adjustment. Cam chain adjustment.

[cprisco13]

I'm trying to search how to do a valve adjustment and everything I search for in the search bar says No Results.  Am I doing something wrong or does it just not work?  I did a compression test on my 72 CB750 with 11k miles and I got only 90 psi on all cylinders.  Engine was warm and did it just how the manual said.  Now I want to check the valves but is there anything else I should do for the compression?

[BomberMann650]

The search function is getting a little maintenance.  So it's out of comission for a bit.

A consistent compression test is a good compression test 

The manual describes the valve clearance procedure.  http://forums.sohc4.net/index.php/topic,17788.0.html

[flybox1]

+1 ^^^
Compression is fine.  Follow the manual for the valve adjustment.

[evanphi]

Nope. Just make sure the engine is cold when you adjust the valves.

[70CB750]

And check the cam chain tension before you do valves.

[BradyN]

I've been using Google to search the site, it works pretty well. Just put in what you're searching, then site:forums.sohc4.net. So in the Google search bar put something like

valve adjustment site:forums.sohc4.net

and it will only search within this site.

As for the actual question, I'm a newbie so can't help there, sorry 

[cprisco13]

Cool thanks guys.  I'm going to do it right now. And Brady thats a good idea for the search!

[cprisco13]

And check the cam chain tension before you do valves.

Ok so I checked the cam chain tension according to the muanual.  And also this video I found online..

Then I did the valves, checked them all and made sure they were correct like the Hack A Week video.  Once I put everything together, and started her up, it definately sounded a little better at first but now the idle is jumping all over and its not getting good revs.  And only the two middle pipes are getting hot, the two outside ones are taking longer to warm up.. Here is a video of the idle and what it sounds like.. Not sure what to do next.

[BomberMann650]

COMPLETE the 3k tune up.

Accurate static timing might fix ya

[cprisco13]

COMPLETE the 3k tune up.

Accurate static timing might fix ya

Ok.  I had to crank the the bolt on the ignition point plate to raise some of the valves... Did that maybe do something? Do I have to set that back to something? 

[BomberMann650]

COMPLETE the 3k tune up.

Accurate static timing might fix ya

Ok.  I had to crank the the bolt on the ignition point plate to raise some of the valves... Did that maybe do something? Do I have to set that back to something?

Ive bumped points out of spec doing manual cranks.
Seems each time ive done valve checks i've had to adjust timing as well.

So check and set the static timing, if nothing else, you've rules out that problem

[cprisco13]

Ok now a whole new monster has entered.  The static timing.  I did how the manual says and some videos,  and adjusted the points to spec.  Now it says to test timing with a light and turn the crank until u see the F ect... This is just confusing the hell out of me.  Do I need a special light meter?  Does the plate need to have the F lined up before I start the engine?  This whole time thing is racking my brain. 

[rickmoore24]

Get a test light and read here.... 

http://forums.sohc4.net/index.php?topic=96637.0

[cprisco13]

Get a test light and read here.... 

http://forums.sohc4.net/index.php?topic=96637.0

Thanks but I've already read that whole thread. Still confused.  I'll have to get a test light and figure it out somehow.

UPDATE-  so #$%*,  after looking at the points and trying to start the bike I all of a sudden have NO Power. Nothing!  Checked the battery, changed the fuse. Nothing works!  Is it possible I did something with the timing plate or something?? 

[BomberMann650]

Double check the battery and key.

As for setting static timing.  I've pretty much given up on trying to do it by the book.

12v test light, extra wire with alligator clips.  Attach ground to the block (the hole for the points cover works.  Clip the gator wire onto the test light, and the other end at the odd colored wire to the point.  Blue and yellow respectively.

With the key on and the kill swith to run, and a battery tender attached.  Slowly turn the crank until the test light comes on.  The light turning on is the moment of spark.
If you are off by ALOT on the 1.4 point, nudge the plate left or right (i can't remember which way is adv, the manual says).  If you are advanced a little, simply closing the point can retard the timing.  Rotate the crank around again.  Observe the moment when the light comes on.

Reapeat as necessary until 1.4 is in time.  On the F mark, as close as you can get it.  2.3 is the same method, except the big adjustment of the point does not require moving the whole plate.  Just point base.  It is really important that you've got the 2.3 point firing at the same relative mark as the 1.4 - motor wont run smooth if 2/3 is firing a degree or 2 off of 1/4.

As for dwell and gap, I've never had an issue with my points not opening enough.
  (Excepting when the set screw vibrated loose mid ride and I lost 2/3 about 30miles from home)
Early experiments with dwell and dynamic timing settings made my 550 run worse than Simply getting the point to open fire on the mark

[rickmoore24]

Just a thought on everything suddenly going dead; if you've checked that the battery isn't the culprit and all the wires check out OK, then check your key switch like Bomber said, especially if it's an Emgo replacement. Mine crapped out on me after a few weeks.

[cprisco13]

Just a thought on everything suddenly going dead; if you've checked that the battery isn't the culprit and all the wires check out OK, then check your key switch like Bomber said, especially if it's an Emgo replacement. Mine crapped out on me after a few weeks.

Ya I actually just checked it last night and I wiggled the wire from the key switch and I got power again.. Very strange.  I do have a replacement key switch installed because the original one stopped working.  I'm going to try to get a tester light or whatever later so I can finish the ignition timing. 

[DaveBarbier]

You can make a test light really quick and cheaply. Two wire soldered to a small 12v bulb with alligator clips on the ends.

That's what I did.

[cprisco13]

Ok, Bomber thanks for those directions.  But I have this gun timing light thing I got it was only $15.  It has a positive and negative clamp(red and black) and also a third weird looking clamp thingy.  How the #$%* do I use this thing.  For some reason I just can't figure this stuff out and I am losing my mind.  I've searched videos and everything talks about the points.  I've done the points, that part I understand.  Now I just can't figure out how to work this damn gun!! Please someone help!!!! I seriously need like a picture or video of someone literally doing this and I seriously can not for the life of me find it.  A lot of the words just aren't making sense to me. Or if there is who lives near Burbank, CA just come over and help! Ha

[70CB750]

The clamp goes on #1 spark plug wire. 

[cprisco13]

The clamp goes on #1 spark plug wire.

Thanks.  I don't know what it is but this whole static timing thing is like one of those math problems in high school that just does NOT make sense at all to me.

[MCRider]

The clamp goes on #1 spark plug wire.

Thanks.  I don't know what it is but this whole static timing thing is like one of those math problems in high school that just does NOT make sense at all to me.

You are over thinking it. Set the point gap at the highest lift of the point cam, x 2. clip the simple light (per DaveBarbier) to the point bolt and to the engine, anywhere, for ground.

Turn the engine (helps if you have the plugs out), light should come on, at the "F". Do the left points (1-4) first, then the 2-4 (right) points.

(I've left some holes, the manual or obviousness should fill)

Put the plugs back in and use your gun. But the static procedure should yield good results, the gun will just confirm it.

[cprisco13]

Ya, that makes sense.  The gun says timing light on it so I thought thats what I can use it for.  I thought I could use it just the same as the simple light but apparently not. Now I have to go get the simple timing light. 

[cprisco13]

Ok so I just checked it with a voltage tester and the points open up and get electricity right when they are supposed to.  F 1.4 and F 2.3.  So everything seems good.  Is that it?

[BomberMann650]

You mean 12v test light?

If the light comes on when the the F mark on the advancer lines up with the mark on the case, then yes.  That is good.