small engine charging system

[mark123]

I have a 6.5hp electric start clone and added a second charging coil so there are 2 under the flywheel now. This engine came with a small diode and the coil I took from a honda 9hp had a small rectifier. Should I keep both independent of each other and then splice them together after their diode/rectifier or could I splice the 2 coils (ac voltage) together and then run them both through the honda rectifier and leave the tiny diode out of the picture.

 

[krakkah]

I'd be inclined to say combine them before the rectifier in case they somehow work against each other? Hard to say.

 

[Axx3d]

Make sure the rectifier can handle the added amps/volts. You could always use a voltage regulator instead of the rectifier and be safe..

 

[mark123]

Well I think I have it working. I have each coil going to it's own honda rectifier from a GX 270 and then directly to the battery. Engine off shows 12.2 volt and at idle and reving up shows 12.4 volts. I disconnected the charging system from the battery and it shows anywhere from 13 volts at idle up to 70 volts at 5000rpm. In this case as with many small engine charging systems the battery acts as the voltage regulator because there are only a few amps. I tried connecting the charging system to a common automotive 1157 bulb and at idle it lights up one filament good and the other filament pretty dim and when I rev it up it lights either one nicely. These bulbs are 8 and 26 watts. I then tried a 55 watt H4 bulb and it would not do anything at idle and made it faintly glow orange at 5000rpm. We ran the sled yesterday and the heated grips worked great and the light does as well and doesn't discharge the battery. After more research I also found that there are 2 different charging coils for the GX series, one has 2 internal magnets and one has 4. I have 2, the 4 is made to work with 2 special coils and will make 88 watts of power. NR racing sells them. I am guessing my setup makes 10-30 watts depending on engine speed

 

[awbagwell85]

This is very interesting to me.....I am rebuilding a gx390 and bought two new coils, I have the old ones of course and as far as I know work just fine. Could I potentially affix all four to the crankcase, run them through a regulator or rectifier to get more juice to the battery, in turn allowing me to run more lights or whatever off the battery without killing it. Sorry if this is worded oddly or incorrectly but I have next to no experience with electrical work.

 

[awbagwell85]

just looked at it and there isn't room for 4 coils.......

 

[Scout]

Each coil should be on its own rectifier, after that the outputs can be combined.

I'm curious to know how far apart in degrees they are from each other.