Timing mod: running or not running engine

[YOBE]

Hi,

will double check my timing on my mercruiser 165HP 70's.
Before I always stopped the engine, loosen the bolt and changed the position of the Delco. Fix the bolt.

I was wondering: if I slightly loosen the bolt so I can turn it with some resistance, could I then leave the engine running while optimizing the timing OR is this not a smart idea?

Its so sensitive that it requires some effort to get it on 6 BTDC...

Thanks

 

[Bondo]

will double check my timing on my mercruiser 165HP 70's.
Before I always stopped the engine, loosen the bolt and changed the position of the Delco. Fix the bolt.

I was wondering: if I slightly loosen the bolt so I can turn it with some resistance, could I then leave the engine running while optimizing the timing OR is this not a smart idea?

Its so sensitive that it requires some effort to get it on 6 BTDC...

Thanks

Ayuh,...... That's how it's done,..... then tighten the locking bolt,...

 

[YOBE]

Ayuh,...... That's how it's done,..... then tighten the locking bolt,...

Ok, seems logic, but wanted to be sure

 

[Lou C]

I’ve done it that way many times. I bought a nice new OTC advance timing light which works better (easier to see the marks) that my old Craftsman. I actually do it with the boat in the water so I can run the motor up to about 2,000 rpm to check total advance. Still have an old school Prestolite points distributor with centrifugal advance but eventually would like to switch to the Delco Voyager system for less maintenance.
Using the manufactures advance chart you can make sure it’s correct with an advance timing light. So if you know that you’re supposed to have like 15* total at 2,000 rpm (just an example) then you run the motor at that speed, set the dial on the timing light to 15* & it should flash at the zero mark in the timing tab.

 

[Scott Danforth]

I set dwell while cranking (cap of), and then rough in the timing, and adjust with motor idling. It's what was taught many years ago in highschool autos

 

[Lou C]

Yes because changing dwell changes timing (not a lot but it does)
Hey Scott
what do you think of my finally ditching the old points set up for a Delco Marine distributor, I'm getting lazy in my old age?!

 

[Scott Danforth]

Hey Scott
what do you think of my finally ditching the old points set up for a Delco Marine distributor, I'm getting lazy in my old age?!

It's up to you. Next you will be thinking OB conversions

 

[Lou C]

It's up to you. Next you will be thinking OB conversions

Nah Scott I'm too dang cheap and suspicious of unknowns, I want to make my old boat more reliable, so an electronic distributor and a new Edelbrock 1409 (have an old Quadrajet, will try one more rebuild, tried a Holley some years back but it wouldn't run right) might be what it takes. I am putting together the parts I need for the 1409 just in case. The Holley was easier because after GM quit building Qjets they used the 4160 as did Volvo.

 

[kenny nunez]

For me to keep from having to turn on & off the water & jumping in and out the boat I also set the dwell like SD. I then attach the spark plugs to the wires and leave them grounded on the manifold, spin the engine to set the timing.