421 cub 35mm or 39mm pwks?

[Valadezj]

I have a ported 421 cub , 20cc domes, cpi inframes , currently running 35mm airstrikers , is it worth the money and time to switch to 39mm pwks. i know i would need bigger boots and probably filters.

 

basically would i notice the difference in power, or would it just make a difference on the dyno

[RadarRacing]

You probably wouldnt notice it by the seat of the pants. Would probably be 3 or 4hp stronger with 39s.

[Nieskes]

39s

[5150banshee]

I run 39's on my 400 and love it... I could tell when I went from 35's-39's

 

 

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[Valadezj]

Thanks guys

[sleeper06]

You will def notice a difference, I run 39s on a variety of machines and if your porting and supporting mods are up to par then you will be satisfied I have noticed gains all over

[trickedcarbine]

Going to the 39's will get you a tad more on the top end, but at the cost of a little bit of bottom end. Are you running it wide open in the dunes and drag racing or do you ride the stuff out west that gets a bit tighter.

[locogato11283]

What kind of riding?

[Valadezj]

I do 60% dune and 40 drag, my question is bang for the buck is it worth buying new intakes and bigger filters plus cost of carbs for 3 more hp

[trickedcarbine]

That's your decision....

[locogato11283]

I do 60% dune and 40 drag, my question is bang for the buck is it worth buying new intakes and bigger filters plus cost of carbs for 3 more hp

 

I'd leave it.

[252wheelieking]

This thread has helped me alot...Thanks fella's im sticky with my 35 PWK's.

[possum]

id leave it as well.

[Valadezj]

thanks for the help il stick with the 35s