Cutting a stock head for 4mm

[matt1]

Can a stock head be cut for a 4mm on pump gas(I am at sea level)? Does anyone know if a prodesign head makes the spark plug sit any higher than a stock head? I barely have enough clearance with a stock head on my hybrid between the gas tank and the sparkplug boot.

[Finch]

http://www.mullengineering.com/sc/store.php/products/yamaha-banshee-yfz-rz-head-mod-billet-cut-modify-machine-squish-dome-plug-heat-race-drag-online-modify-modification

[matt1]

Thanks, I was told by another sponsor that they would not cut stock heads and that they did not recommend doing it on a 4mm. Any ideas why?

[Finch]

No idea but i have heard good things from mulls cut heads. most prolly dont do it cuz many dont actually cut their domes the calculate them and order them

[trickedcarbine]

X2 for Mull. There is nothing wrong with cutting a stock head and re chambering the domes. I had to use a stock head when I ran my Big bore motor and it even ran about the same temp as the PD cool head

[01bansheefox]

My builder McCoy recommended cutting stock head vs going aftermarket for my 4mil im going to have him do.

[trickedcarbine]

McCoy is one of the best. There's an opinion that holds weight.

[sleeper06]

I have personally had a few heads cut for 4 mil by mull engineering,you will not find a more knowledgable guy on dome design and his heads are top notch work there are a few site members bikes that I have built running them with no issues,and going three seasons strong