Cub cylinder porting

[Oregon dunner]

Hi guys,

I have a 4 mill 421 cub motor 17cc domes and v-force 3 reeds with 39pwk carbs. I want to get the cub cylinder ported when I replace the top end. I was wanting to know the best all around porting for these cylinders? I usually just do tree shots and friendly drag racing here and there and there. Any suggestions?

 

Thanks

[RadarRacing]

Tree shots or duning 70 percent of the time and dragging a little I honestly wouldnt even port it. If you think of it as a drag ported cylinder that can get another 5-10 percent with porting and definately a little loss in lowend, I dont think I owuld port it further. Just my .02cents

[camatv]

depends on the porter..

 

cub timings on a 4 mill are 198* and 130ish transfers. those are high numbers for a "rider bike" but overall are a lot of fun. there is some that you can do to the intake and if the cylinder is right out the box installed it can be cleaned up and flashing clear'd and ports smoothed. that overall would help with the power of the cylinder

[06specialedition]

Call Brandon at Wildcard Racing

 

435-623-0148

[BigRed350x]

I would call Kevin at HJR. Great guy to deal with. He can get you plenty more out of your cub. I wouldn't hesitate to have him do any work I needed done. Fast turnaround time, he doesn't farm his work out to anyone else to do and won't try and sell you any crap you don't need.

 

His contact info is in my signature.