<VV> Timing

[larry at forman.net]

Hi Ralph,
Here are some other ideas:
1. First, double check (or better replace) the cross over tube rubber 
hoses and make sure you use hose clamps to secure them.  These tend to 
cause vacuum leaks a lot.  Much better than rubber hoses is the more 
recently available silicone tubing.  It lasts a LOT better in the hot 
engine environment.  I know it is available for the small vacuum lines 
and I suspect it is available for the thicker vacuum line also.
2. I would cap off the secondaries and remove the secondary actuating 
linkages.  If the secondaries are not adjusted right, it could be not 
closing properly and causing a vacuum leak at the secondary venturies.  
By capping them that part is out of the equation.  Removing the linkage 
just keeps everything like a 110.   Get it running the best it can on 
the primaries and then add the secondaries.  You can cap the 
secondaries by making block off plates to replace the plastic spacers.  
That will assure the secondaries are totally out of the picture.
3. Before I would do any other troubleshooting, I would check the 
cylinder compression, if it has not been done.  No amount of fiddling 
with the carbs or ignition will make up for one or more weak cylinders.
4. You can also perform a cylinder balance test easily if you have a 
good tach.  Just pull back the rubber nipples around the distributor 
cap and get a paper clip straightened out a little and a good grounded 
clip lead.  Using good rubber gloves, or insulated pliers, slide the 
grounded paper clip into each distributor plug lead and read the idling 
rpm.  It should drop a similar amount for each plug wire shorted to 
ground.  Record rpms for each cylinder and see if the engine is 
balanced.

HTH,
Larry