Dual point timing on Convert

[bigbikerrick]

Hi Folks, I have been trying to get the timing right  still on my vert. I have set the gap on both points correctly, at the mid point of .016" gap, and I elongated the mounting plate holes for the left cylinder points. I have adjusted the distributor to where the low speed mark is in the window, as it should be at idle, then using strobe light, the advance mark is lined up where it should be at 4000 rpms.
  Now moving on to the left cylinder.... the timing mark at idle is down below the window, which is about 3 teeth too advanced , but when I rev it to 4000 rpms, the "advance" mark is centered in the window ,where it should be. If I adjust the point late where the idle timing is correct, on the left cylinder, then its too far advanced at 4000 RPM.

The bike runs great at high speed, but the idle is a little "lumpy", and occasionally stalls out at a stop light. What do you all recommend? Do I retard the left timing, so the idle is better, or just time it to the full advance mark?  I sure would like to get it spot on, if at all possible.
Thanks alot
Rick D.

[acogoff]

     One thing to check is make sure when you are doing the static timing that you hold pressure on the cam with you hand counterclockwise to take up any play. Sometimes the mechanical advance
 has some play or weak springs do not bring the cam to the stop.

[guzzisteve]

Run it, not a perfect world. Set your idle w/the brake on so it doesn't stall. How often do you use the clutch, got to figure which works.

[pehayes]

What are you planning to do with this motor?  Land speed racing?  Or sedate cruising?  The Convert seldom sees high rpms.  Just my opinion, but I would be much more concerned about idle timing accuracy than speed.  Do what is necessary to get both idle marks the same and ignore the high end.

Have you ever changed the distributor weight springs?  They age with heat and get weak and allow the advance to come up too early and too quickly.  Consider stiffer springs to hold the timing back which is more appropriate for the low rpm touring.

YMMV.

Patrick Hayes
Fremont CA

[bigbikerrick]

I have not checked the springs, Pat. Other than looking at them when removing and replacing the points. I guess that should be my next thing to do.

acogoff, when I checked timing, I did not use a static test lamp, only a strobe timing light( handed down from my Dad!)

I agree as far as the Convert not being used as a high speed "racer". but more of a cruiser, and tuning to lower speeds would be better, although Guzziology recommends setting both cylinders to the "advance" mark.

Thanks
Rick D.

[chuck peterson]

Dr Dave in Guzziology has an excellent section covering the springs. He give’s measurements and descriptions

My experience was i received the wrong springs when ordering the vert ones (eh, springs are springs…)

As an experiment i put them in. It made the Vert run terribly slow on take off. I have a theory verts have a slow reputation because of that..

The correct new springs made a difference for me and makes a low range take off quite lively.

Can i ask how you’re determining 4000 rpm? And are you pulling the clutch or not when doing the timing ?

I would hit full advance w the timing light on the centerstand, then go run it. If it pings a bit at full throttle , back off the timing a bit. If it doesn’t, advance it a touch, then repeat ride. A touch of octane booster helps, i used that..

If I remember I’d close the gap on the left point

[chuck peterson]

     One thing to check is make sure when you are doing the static timing that you hold pressure on the cam with you hand counterclockwise to take up any play. Sometimes the mechanical advance
 has some play or weak springs do not bring the cam to the stop.

Nevertheless considered that! Good , ahem, point…

[bigbikerrick]

Thanks Chuck, for the suggestions. I will pay extra attention to the springs. as far as determining 4K RPMs, its just an approximation, by engine sound. I rev it slowly, watching the marks through the hole in the bellhousing, with the clutch lever strapped down. I have also looked at it , with the bike on the centerstand with the tire spinning. I think it works out about the same. Ive got it running and idling pretty good now, except for an occasional mis fire , and stalling out at idle.
Rick.