Originally Posted by
jorgan
Thanks, I got the RCexl unit, well is in the post. So yes an audible or led indication is always the best way. Is there a way to test the CDI units, to see what their dwell characteristics are? I suppose all motors have there own characteristics too? I bet these question have all been asked and answered.
There are folks who have tested cdi units and have posted characteristics. Try the search engine here and on RCG.
All engines do indeed have different characteristics. You can play with static timing and fuel mixture to squeeze out extra ponies, however it's risky. 28 degrees btdc and the leanest mixture possible, in the air, is the safest i.e. the engine will just quit running, with no harm done, if there is a fueling issue or overheating issue. The engine will not detonate, it will just quit running.
Advancing the timing requires a complimentary richer fuel mixture. If you experience a fueling issue, for example, the engine could run too lean for too long, causing excessive heat and detonation. Not a risk I'm willing to take for a couple hundred rpm gain.
Here I am merely parotting Bert's expertise and evaluations. He's the expert on the finer points of internal combustion engines. If I have posted incorrect info he'll be along to correct me......which I truly enjoy.