When you install C&H ignition Syncro spark they tell you to set the timing 28 degrees above top dead center but when I look at a Fox 4.2 and a BME 44 it is only about 4 or 5 degrees above top dead center. Do they make two different styles.
Thanks
Milton

the manual specically states 28 degrees BEFORE top dead center go with the directions

If the Fox and BME have the Syncro Spark, and both are suppsed to, then they are timed at 28-30 deg BTDC.
The timing may look different because the way the igition trigger works. The ignition fires when the magnet leaves the sensor not when it arrives or center to center.

Milton,
I questioned that too. I'm using a Synchro Spark unit on my Homie 25. I read the directions, (with lots of typos) and they alluded to set the timing at 28 deg for both standard and Synchro.
I set my timing at 0 on the Syncro and as the RPM builds it advances timing to 28 near full throttle. The engine runs great there!
I sure as hell didn't want it fully advanced when I was flipping it!
I'm going to confirm it with a timing light the next time I run it, but at 0 deg static, the Syncro Spark works fine for me.
After all, the job of the Synchro unit is to give
0 deg at idle for smoothe idle and kick free starting, and 28 deg at the top end for max power.
Barry

I have both types and you set both at 28 degrees BTDC.

The syncro spark retards the timing with the first few pulses but brings back up fully by the time your at 4 or 5,000 rpm.

Its main purpose of the syncro spark is to be able to start a high compression engine without it kicking back.

To put one on a stock weedie engine like a Homelite or Ryobi, is unnecessary.

Finding true top dead center may be your problem?

Good luck

Jim

Retarded timing makes for a much smoother and lower idle RPM also.

Then the syncro-spark DOES have a better idle say on the Poulan 46cc conversion? or is it unneccessary?

OK DA WORD
A Syncro Spark is an electronic RETARDING device.
If you set your engine at anything other than full advance while using a Syncro Spark it will NEVER develop max power.
Its a long explanation but it knows RPM from the first turn. At a carrythrough 180 rpm it retards 26 degrees, below 180rpm it is full advanced so that you can set the static timing. The average modeler can prop a Sachs 4.2 at 450rpm. Most of the small weedies don't need the Syncro because they don't have enough compression at cranking speeds. A Syncro will let the engine idle a bit slower, important on a J-3 but not on an Extra, but add no power on a properly set up engine.
The crossover point of needing or not needing a Syncro is around 30-35cc.

Well as soon as I can I'm going to get the new Poulan 46cc kit, that is unless somebody else has similar or better. Maybe next week now that I'm back at work driving a mixer truck.