a few questions to experts about CDI
12-29-2004, 10:27 AM
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a few questions to experts about CDI
Howdy Folks. Happy holidays to y'all. 
I have a few questions to convert-experts out there.
1-How low idle speed is on average converted engine with appropriate prop for the given engine?
2-Is advance curve on the electronic ignition a linear or not?
3-At what range advance working on CDI? For example between 2000 and 7000 rpm or between 1500 and 4000rpm or from idle all the way up to max rpm...
4- Whats the max rpm one was able to get out of converted engine with the right prop size?
Thanks for taking time and letting me know.
Mitty
I have a few questions to convert-experts out there.
1-How low idle speed is on average converted engine with appropriate prop for the given engine?
2-Is advance curve on the electronic ignition a linear or not?
3-At what range advance working on CDI? For example between 2000 and 7000 rpm or between 1500 and 4000rpm or from idle all the way up to max rpm...
4- Whats the max rpm one was able to get out of converted engine with the right prop size?
Thanks for taking time and letting me know.
Mitty
12-29-2004, 12:45 PM
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RE: a few questions to experts about CDI
Idle speed is determined by the weight of the prop, a really heavy prop will let the engine idle at 1000 rpm..
Advance curve on a Syncro Spark starts at idle and is mostly linear to 4000 rpm, full advance from there..Total advance is about 26 degrees...2 BTDC at start, 28 at 4000...
CD does not change the max rpm if the engine was timed at 28 in the first place, and more than 28 is useless anyway....You can NOT measure the rpm difference between 28 and 30....You probably can't set it without a degree wheel, and 2 degrees just doesn't make any difference on our 2 strokes....Way MORE than 28 degrees makes the engine run too hot and miss...Way Less than 28 slows it down....
Advance curve on a Syncro Spark starts at idle and is mostly linear to 4000 rpm, full advance from there..Total advance is about 26 degrees...2 BTDC at start, 28 at 4000...
CD does not change the max rpm if the engine was timed at 28 in the first place, and more than 28 is useless anyway....You can NOT measure the rpm difference between 28 and 30....You probably can't set it without a degree wheel, and 2 degrees just doesn't make any difference on our 2 strokes....
Way MORE than 28 degrees makes the engine run too hot and miss...Way Less than 28 slows it down....
