Motor build

[Vmash44]

Just bought a banshee that I’m trying to figure out what route to go with, looking to build a decent dune bike that’s capable of kill climbs but not looking to touch the bottom end yet. Looking at stock bore or something mild. Don’t know what carbs, head, jugs or dome, not sure on anything. It previously had 66mm pistions in it running on a single quadzilla carb. Other than that I have no clue what is done to it. Looking for advise how to build this 

[Jereme6655]

Well if it’s got 66mm pistons that means it’s 80 over……..aka you’re about at the end of the life of those cylinders. Some say you can go to .100 over, but most of us stick with .080 being the biggest that you can bore it. Stock bore is 64mm. 
 

call a site sponsor (I use Jeff at FAST RACING)….talk to them and tell them what you know about the bike. They will ask you what your intentions with it are and they’ll get a pretty good feel for your riding style through conversation and recommend what they think is best. Chances are, at 80 over….. you may wind up having to break into the lower just to verify that it’s still good. It would be terrible to build that engine up just to have a crack failure because it’s past its prime and destroy the new stuff. Realistically I bet you’re gonna be in it cylinders, pistons, carbs depending what cylinder setup, and a top and bottom refresh/rebuild. 
 

other option is just ride the piss out of it and start gathering parts or ideas and wait until something goes wrong, then build it up.

[locogato11283]

I wouldn’t do anything until you’re ready to build a 4mm motor. Doing anything other than that is a waste of money.

[Tedder]

3 hours ago, locogato11283 said:

I wouldn’t do anything until you’re ready to build a 4mm motor. Doing anything other than that is a waste of money.

Agree 100%

4mil ported Serval

[trickedcarbine]

Cylinders are at the end of their life. Likely the bottom end is as well. It’s one thing to build a different top end for a motor you know, but it’s questionable in your case. Agreed it’s a waste of time to do anything but a 4mm. Either leave it as is, or build a 4mm set up. You really should go through the whole thing top to bottom. It’s not as bad as you think. The first time you split the cases, it all starts to make sense. Since you’re on the hunt for cylinder options, I’d say do a Driveline Assassin set up or a Serval Cub. Both super stout set ups that will handle hills and dunes. Driveline has very good pricing for packages like cylinders and all the supporting parts including the crank. 
 

Definitely ditch the 2/1 carb. You can even go back to stockers and get them jetted well, and it’ll be super snappy. 

[gusto]

Driveline 392, 33pwks vf4 reeds and you’ll have a great engine