Hi, I was wondering if you can tell the difference between the syncro spark or just the standard ignition. {On the idle or starting} I am putting it on a weed trimmer engine.Thanks!

POWER

What kind of ignition is the "standard" ignition ???? If its CDI you'll notice alot of difference....CH will be much better

I will assume as you suggest the std. ignition is the stock weedy ignition?

If you replace the std. weedy ignition with a C&H Ignition SS Auto timing unit yes the starting should be much easier and safer. Of course I am assuming the weedy ignition is a constant timing unit.

Note: there are C&H Ignition modules that require a mechanical or some other form of device to change the timing based on rpm, start up and maximum RPM.

On a weedie there is no improvment at full throttle with a SS unit over a CH unit with fixed timing. Start up is about the same and there is a few hundred RPM diff at idle( the SS will idle slow and smoother)
Reason?? most weedies have one ring and poor compression at cranking/slow speeds, so there is little kick back.
Two rings and 35CC is about the cross over point where you DO NEED the Syncro or a mech timing control

Makes sense, but.

Isn't the timing on the fixed C&H unit usually set at a lower figure than the SS unit at full advance? Surely starting an engine at say 4 degrees verses say 24 degrees, low compression or not would be substantially safer??? Another benefit might be a smoother mid-range and transition with the SS??

You seem to have lot of knowledge with weedy conversions???

He does, and nope..All units are set for 28 degrees full advance, SS or not..
We went through this a while back when someone said the fixed timing on one of the leading "high dollar" engines was not 28 degrees..The fix was/is an upgrade to SS..Looks like just another way to add $$$ to the price of the engine. 28 degrees fixed is NO PROBLEM on small engines......You just have to flip the prop with AUTHORITY.......(And a glove)....

Most weedies are set up by power mad fliers and are timed at full advance 30 deg BTDC. That is why there is no improvemnt with the SS at full throttle.
Ive run 4.2 Sachs with fixed timing @ 30 deg BTDC. Its not real bad but you have to be firm about starting it or you will get bit. But the weedies size and low comp make it much safer. If you have a timid flip when trying to start an engine or worried then by all means add an Syncro to your weedie.
TKG
CH Electronics
Yes I do know a bit about weedies

Now you've done it..Blew your cover..Can I tell everybody your nickname ??

That Riverton address blew his cover long ago!
Nobody has mentioned the weight aspect of the weeder conversion from CH.The stock flywheel and coil,weigh close to a pound,and even adding back in the weight of the CH unit and a battery pack to bring it to life,I reckon the weight saving at around 10oz,important on engines this small,particularly in 1.20 sized models.The flywheel often gets in the way depending on the model involved.The CH "kit" comes with a very professional prop driver with the sensor magnet imbedded in it,and the only things left to buy for the conversion are a mount and muffler,although the stock muffler can be used and a mount is easily home made.
I never had much luck starting the Ryobi by hand until it was warmed up,due I assume to the anemic compression ratio,so I just use my standard Tower HD 12V starter.
I ran some static tests last nite,on a well broken in 31cc unit,87 octane,Honda synthetic 40/1 and got:16x8 wood 7600,16x8plastic 7800,18x8 plastic 7200.This was with the high end peaked with a tach and then backed off 1/8 turn.
I,m now going to install one of Frank Bowmans replacementcement rings,break it in as he recconends and test the same props again.I expect easier hand starts,a steadier idle,and maybe some more on the top end.I dont beleive in revving the guts out of Ryobis.They cost about .29 cents to make ,and take many quality shortcuts including that con rod that looks like a grenade going somewhere to explode!,so if I get more top end Ill use more prop......I wont argue with anyone who says the McCullogh or homelite are better weeders quality wise,but the Ryobi can be bought factory reprocessed for $60,is a neat fit in narrow cowls,and there are numerous places making parts or conversions for it.
Before anyone asks for my credentials,Ill tell you I have owned 4 Ryobis,done the conversions on three of those,use a CH ignition on the current one I am flying in a SIG 4/120,and Im not even close to the league RC IGN,and the boys from Riverton play in !

OK, Ralph, tell us all what the nickname is. I think I have heard it before.

-ed

Never :devious:

Bill at C&H and I call each other "Brand X"..However, TK's nickname will remain a mystery, just like TK himself.... :devious: