Topic: 2-3 timing question

[stueveone]

Hey gang,
So I am in the middle of timing up the ol 750k4 and am running into a strange timing problem. When trying to set the timing, cylinders 1-4 are fine, right on the money. But 2-3 are not even close, and I can't get them close. They are way to the left of the "F", and more closely line up with the "T". The advance is similar, way to the left, which would be near the "F". Now, the advance mechanism is from an old bike, and the points and condensors are new.
Any suggestions?

[kettlesd]

Forgive if this sounds completely apparent - but how are your point gaps (having the point gap too small will retard your timing like that ), and did you adjust cylinders 2-3 separately on the sub plate on the right hand side of the main plate? You adjust cylinders 1-4 first, lock em down and then you do 2-3.

[TwoTired]

My suggestion...
 Read the FAQ

http://www.sohc4.us/forums/index.php?topic=5752.msg47539#msg47539

[stueveone]

Thanks guys!
Yes, both points are set at .012 (unfortunately I don't have a dwell meter) and I adjusted 1-4 first and then moved on.

Twotired, I read your post on the FAQ earlier today but I'm a bit confused. So where do you put the feelers gauge? between the large plate and one of the three mounting columns? I'm just not sure what you are trying to achieve.

[TwoTired]

I'm just not sure what you are trying to achieve.

Frustration, I guess. 

 I don't know how to explain it any better than what's in the FAQ.
 

Best of luck!

[stueveone]

"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."

--Right, got that, that's what makes timing possible for 1-4. In theory, if all three notches were wider/longer, they would yield more timing adjustment.

"find the largest feeler gauge that will insert in the gap between mount post and large breaker plate. "

--Is this between the edge of the large breaker plate and the highest wall of the mount post? If that is so, wouldn't it wedge and make it hard to turn the large plate?

"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"

--If I'm reading this right, are you saying you slit the feelers gauge down the middle a distance, and then bent one of the newly made ears perpendicular to the other ear?

[TwoTired]

Perhaps you misunderstood the concept of "radial".  A radial is a line from the center of a circle to it's outermost point.  The plate, which is round, has no adjustment for that.  It only has slots for adjustment along it's circumference, the distance around the outside of the circle, like a degree wheel.

If your plate is too small for the captivating posts, it can move laterally by the amount of the size difference.  The feeler gauge is placed to keep the plate from moving up and down or right and left relative to the earth's surface.  This movement can change your point gap, Dwell, and ignition timing.

--Is this between the edge of the large breaker plate and the highest wall of the mount post? If that is so, wouldn't it wedge and make it hard to turn the large plate?

You select a feeler size to keep the plate from moving within the posts. It should still be able to rotate.  Don't let the point's spring pressure interfere with your gauge selection.

Hope this helps,

[stueveone]

Gotcha. I went outside after my response and just tinkered around. It didn't take long to figure out what you were talking about, the plate has play up and down or side to side, and depending on where the points are pressing when you stop the engine, will give you a different reading every time. So I stuck a feelers gauge inbetween the edge of the large plate and large wall of the mounting post (bottom right). Then, I mounted the points and gapped them to .013 this time (I previously gaped them at .012) and low and behold it was right on, timing and everything. The bike idles at 1000 like a champ. And yes, radial as far as radius, got that. I think am confused as to what you mean with the sacrificing your feelers gauge L shape thing  )
But thanks man for your help. I really appretiate it. I was thinking about the tool I'd design for this problem, and how about taking a feeler gauge and first bending it like an L with one side the exact leght of the large plate edge, and then notching out the other side so it fits around one of the mounting bolts? kind of a horseshoe thing?
Huh, maybe I'll make one up one of these days.
Thanks again!