what do they do?

[bansheerider4]

what exactly do cool heads do?and could you explain the domes(like 20cc or 21cc domes?)

and would it be something youd wanan have for trail riding and pit riding or no?

[firefighterjosh]

Cool heads is a name: they have larger coolant passages that let more flow to help cool the engine more effective. From what I have heard they work.

Domes: from what i have read the larger the dome size the more comppression the engine will have since it makes the dome smaller

20cc = larger dome less compression

22cc = less dome size and more compression

I think I have that right:o

[bansheerider4]

does that increase hp at all?

[firefighterjosh]

Yes they do. Increased compression = power lol. Also I think the domes are smoother or shaped diffrent too. Not sure I never owned one. My friend had his stock head rebronzed or something like that and it gave it some more power. Someplace in georgia did it, but he is in iraq so I can not ask

[mickey400ex]

less dome size will raise the compression, if your compression gets over 160lbs, then race gas is probably a good idea:)

for around 30 bucks you can you can have your head milled to raise the compression, the limit of milling it is around .30 over to run pump gas, i did it and trust me i could notice the power in the bottom end