Small Engines (Lawn Mowers, etc.): briggs 5 hp flathead, correct voltage, magnetos

Question
i have a 5 hp flathead and i took off my 5 horse flywheel and put a 3 horse on it and made a bracket for the magneto and this engine with no points behind the flywheel and i set the magneto at .001 just like the manual says and i get no spark from it. i am using a aluminum 3 horse flywheel and a 5 horse magneto. would any of the two make a difference i was told to switch to a steel flywheel but he wasn't for sure pleaaasssseee help i am getting frustrated!!!!!!!

Answer
WOW.... what a project!  in theory you should have spark, but weather its introduced at the proper time with the correct voltage is another thing.  Since you have not given me any model numbers its very hard to help u with this.  

The magnetos are NOT the same for the flywheels,

Why did you take the flywheel off in the first place to change it?  This is not on a gocart engine is it?  

I'm sorry i cant help you more, but your question is really vague, send me a followup with the model type and code numbers of both engines and that will allow me to help you.