Author Topic: Stock full advance timing degrees  (Read 854 times)

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Offline mtn

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Stock full advance timing degrees
« on: July 04, 2019, 04:56:39 PM »
I've got a '75 CB750F and my search-foo is failing me. What should the timing degrees be at full advance with a mostly stock motor? It looks like 35deg is standard but I haven't been able to find a definitive answer.

Offline Airborne 82nd

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Re: Stock full advance timing degrees
« Reply #1 on: July 04, 2019, 07:47:38 PM »
Not sure why you need to know is this engine apart or together ? Have you tried to set it on the marks?

Offline PeWe

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Re: Stock full advance timing degrees
« Reply #2 on: July 04, 2019, 09:29:05 PM »
I adjust my CB750 according to the marks. At idle and full advance not before 2500rpm.
I had to cut both adv springs 1/2 wound on both my CB750's to make that to work.
 Advancer has a play, set it to max counterclockwise and marks will be true.

I do not care of any degrees, only when timing a cam, not stock one.

I'm sure that wrong information that more advance will work better is spread worldwide
 I saw on Dyno that only a few degrees more advance than the marks lost HP. That on my modified K6.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline scottly

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Re: Stock full advance timing degrees
« Reply #3 on: July 04, 2019, 09:52:47 PM »
The stock full advance on a 750 is 35* BTDC: 10* initial plus 25* centrifugal, all in by about 2400 RPM.
Don't fix it if it ain't broke!
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Offline mtn

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Re: Stock full advance timing degrees
« Reply #4 on: July 05, 2019, 06:37:58 AM »
Exactly what I was looking for, thanks scottly!

For the curious, I recently swapped out the stock advancer and points for a Dyna 2000. The Dyna has no 'F' marking, as it's intended for several different makes and models. During the static timing procedure you set the timing based on the full advance.