Timing question

[OW'73]

Ok. I'll try to make a long story short.
1973, 1700, weber progressive, svda.
I disconnect vacuum from dist. Plug both carb and distributor.

I time at 3500 rpm and timing mark hovers between 28-32.
I go past 3500rpm timing mark does NOT advance.

I connect everything back up - ie. vacuum from carb.

I recheck timing - past 3500rpm it keeps advancing all the way to 40.

So I time with everything connected. At 3500rpmto 4000 rpm, mark hovers between 28-32 and does not advance.

Question #1
When you guys time your engines does the mark have some movement or does it stay steady as long as rpm's are constant.

Question#2 - The more important one.
I thought timing was done with vac disconnected. Am I missing something. It kept advancing when timed with vac disconnected.
When I timed with vac connected I seemed to be able to hit the magic number.

Thanks

[Amskeptic]

weber progressive, svda.
at 3500 rpm, timing mark hovers between 28-32.
I go past 3500rpm timing mark does NOT advance.

Excellent.

connect everything back up recheck timing - past 3500rpm it keeps advancing all the way to 40.

As it should now that everything is hooked back up.

I thought timing was done with vac disconnected. Am I missing something?

Check timing with hose disconnected. Make sure that centrifugal only does not go past 28-32* at 3,400 rpm. That means rev it to 4,000 with hose off please, and you must not see any more advance than what you read at 3,400. If it does, disassemble and lubricate centrifugal weights. The only reason you get additional centrifugal only past 3,400 rpm is that the weights are not reaching max soon enough, usually due to sticking. Lubricate the wick at the very center of the distributor shaft where the rotor normally sits. There may not be a felt wick, lubricate anyway with one drop of oil.

With the vacuum hose connected, you should easily hit 40* before 3,400 rpm. It is supposed to drop back as you goose the throttle, then snap back up and come down as the engine returns to idle. Any deviations with a good hose and healthy vacuum can suggest a lousy signal from the carburetor.
Colin

[OW'73]

Ahhhh. I see

It did run a bit crapier after I timed it to 32 with everything connected. I'll re-time tomorrow.

Thanks.

Now what about the "hovering mark" it fluctuates between 28-32 while timing. Normal?

and thanks again.

[Amskeptic]

the "hovering mark" fluctuates between 28-32 while timing. Normal?

Normal enough slop in the gears and distributor bushings.
Colin