Simple predator 420cc kart build advice?

[Doc Sprocket]

For your purposes? Probably standard race kart stuff. Small slicks. If you want something that might look mean, maybe look into some larger Jr Dragster slicks for the rear. See what you can find- Something will tickle your fancy, but avoid going too large. Bottom end may start to suffer.

 

[OzFab]

If you want to keep the budget in check, do yourself a favour- get a small block, not a big block. A 6.5hp 200-212 cc engine with very mild performance upgrades will serve well and end up costing a lot less. Part of the reason for this is that the 420 has a 1" PTO shaft, whereas the small engines have a 3/4" shaft. Any clutch or CVT is going to cost more in 1" than 3/4". Then, there's the purchase price of the engine, too.

... not to mention a bigger footprint, which would mean modifying/replacing your engine mount &, as your mount plate also supports the axle, you'll have your work cut out for you.

IMO, your best option is to go with a smaller engine & shed some of the bulk from the frame

 

[ivanivz]

im thinking 10'' tires up front and 11'' in the rear should fit my kart and wont be to wide and will save some bottom end,

 

[Doc Sprocket]

That sounds reasonable.