Author Topic: Points wont turn enough  (Read 1374 times)

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Offline Flying J

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Points wont turn enough
« on: September 10, 2009, 12:01:03 PM »
 i bought a bike that didnt run. I was told it was "something with the points". i static timed the bike and i had to rotate the points plate all the way to one side. After cleaning up the carbs the bike runs. The problem is that when i use a timing light the points need to be turned a few degrees more but the slots are tapped out, i cant rotate it any more. What is going on here? Anybody have this problem?

Offline scunny

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Re: Points wont turn enough
« Reply #1 on: September 10, 2009, 12:10:04 PM »
is the points backing plate correctly aligned, can sometimes be off centre putting timing out
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Offline mark

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Re: Points wont turn enough
« Reply #2 on: September 10, 2009, 12:12:11 PM »
sometimes you have to fuss the point gaps a bit to make timing work out.
rubbing blocks wear and cheap points often don't fit right.
also verify that the advance unit isn't stuck.

is the points backing plate correctly aligned, can sometimes be off centre putting timing out

that too.





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Offline Slayer

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Re: Points wont turn enough
« Reply #3 on: September 10, 2009, 12:36:36 PM »
This is in the FAQ's

   
Running out of timing adjustment range with points plate
« Reply #7 on: December 01, 2005, 01:09:52 am »
If you remove the points from the plates and loosen all three large plate mounting screws, you will find that that large plate will move some distance radially on the mount posts machined into the engine case.  This movement is why you run out of adjustment range, as some plates are different diameters, and some engines have been machined to a different tollerance limit.  The spring pressures of the points pushes the plate in the opposite direction against the mount post. This puts both points in a position relative to where adjustment range is limited.
What to do.  While you have the points removed from the plate (thus all spring tension) and all three mount screws lossened, find the largest feeler gauge that will insert in the gap between mount post and large breaker plate. This is also the point gap error and directly impacts timing.  Reinstall the 1-4 points, set the gap and the 1-4 static time with the feeler gauge still inserted in the lower right mount post to breaker plate gap.  I sacrificed a feeler blade and cut one in an L shape to fit under the mount screw washer, so it wouldn't fall out during plate rotation. This way I can change the 1-4 timing while the bike is running (dynamic timing) or not (static timing).  In my experience, this brought the adjustment slot for both 1-4 and 2-3 points into an acceptable adjustment range.
How did I figure this out?  Well, the bike showed me this problem.  One day, while trying to dynamically time the engine, I had all three mountplate screws loosend while the engine was running.  It was then I could see the whole friggin plate moving around in the engine posts.  Dwell readings were all over the place, too, depending on which mount screw I tightened first or when and where the engine crankshaft was positioned when a mount screw was tighened.  Putting the plate in a stable position eliminated all the variability of time and dwell.  Then I found that if selected the right post to remove the excessive plate movement, the adjustment ranges of the slots were more than adequate.  So, I made a new tool, and, added it's use during the adjustment procedure.
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Offline Flying J

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Re: Points wont turn enough
« Reply #4 on: September 10, 2009, 02:08:58 PM »
Thanks, Ill try and figure out what that faq section post is all about. It was a little confusing the first time through but im glad this is a semi common problem and im heading the right direction to sort it out. Thanks

Offline shizzomynizzo

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Re: Points wont turn enough
« Reply #5 on: September 10, 2009, 02:38:28 PM »
happened on my 550. try playing with the gap, start in the middle of the range, then low and then high. if that don't work, get an oem plate
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cycleman

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Re: Points wont turn enough
« Reply #6 on: September 10, 2009, 04:47:51 PM »
Once you get the main plate set right for #1 & 2 and you move onto 3 & 4 your sometimes have to adjust the point gap slightly on 3 & 4 if you are out of room on the second point plate.

I have to do this on my 77 wing.  Your usually looking at a change of about 2 thousands.  As long as you can stay in the point gap range  ie: 12-16 on the wing, you shouldn't have any issues.