[axle of evil]

how really important are these in the cooling stakes ?

 

[EPR]

You need some fins to cool the coil and cyld. No more than half of them or as close as possible.

 

[CAM2]

Basically modded its not critical and you can get away with a lighter 6 fin flywheel...The more modded and crazier you make the engine you tend to make more heat and run a bit more hotter therefore a flywheel with 9 or twelve fins work better for my builds.........I run mainly a 12 fin though and theres also such a thing as making a flywheel too light aswell....

 

[EPR]

I cut my first fins with a hacksaw, that an a good file and some sandpaper, can do Wonders.

 

[axle of evil]

yea ok cheers. Wasn't sure how critical temp etc needed to be, so if you can do away with few fins or keep all of them and machine down the lip and sides of the fins so i can try a different coil ? ( roughly looks like it will be making the fins 2/3 of the fins normal width)

 

[EPR]

On my big bore big power engines I added weight to the flywheel, w/ 10 bolts, 5 on each side to get 400 grams. It makes eaiser starts, adds smoothness and better top speed cause that weight carries the bike when you get it turning fast. On a more stock engine, lightening is good.