gusto

A 521 for riding trails! How did it come to this decision? Genuinely curious.

RDZ version 2 should be considered as well as CPI

Glad to hear it's running good. How much power increase do you feel and I imagine it's all up top? fuel economy is the reason I run 28 mm max.

Sweet!! learned something new today

I see nothing wrong. Don't look too rich. How do the plugs look? not hitting rpm has me thinking stator or cdi although nothing was wrong before the rebuild...

CPI.

You get it figured out?

Must be sold anyway. Been emailing him a while now

Brutal

...

10 mil serval or driveline low port for the engine with pro mod tranny fireball or lsr long travel a arms fireball +4 or 6 swing arm shock or your choice cpi pipes

Will you be drag racing, woods riding, duning, flat tracking ...etc

Great way of putting it

No. A 421 piston is 68mm so that will be with aftermarket jugs like driveline or CP Industries (cubs and servals for ex). What you do is get a 4 mil crank (longer) and have a builder match the porting to that longer crank and cut domes to account for extra stroke. A set of stock cylinders are good to 66-66.5 mm piston so that puts you around 400cc ish. I would highly recommend you call some builders like the ones that sponsor this page and get quotes then send off your engine. Also, use the search function and read up on some of these builds. Good luck with your build Sent from my iPhone using Tapatalk

And sell your pipes for CPI.

Do a 4 mil stock cylinders build with a dune typ port. Keep stock carbs but add billet bowls, add a shift mod (like a promod), billet clutch basket, driveline head, and hot rod crank. You'll be within your budget and making 75-85 hp.

Entirely depends on how much money you want to spend. So what's the most amount of money you will spend ?

PM me price if still available

Will reed spacers help for clearance? Does anyone here run reed spacers to help clearance issues? yes I know it's one more thing to cause an air leak just curious

I know your still tuning it in, I am real curious to hear how much of a difference the porting has made.

CPI

Claude let's see the port work?

Your cylinders were ported therefore lowering your compression.

Your going to want to start big and go smaller. I would start with a 290 main jet. Buy 290 and start leaning out. Buy like 5 sets of jets. Pilot will most likely be 27.5 use youtube for carb sync

try a different cdi. test your stator