Zillaguy Posted March 4, 2013 Report Share Posted March 4, 2013 I want to build a 421 motor for my trail bike.. It doesn't have to be the best of the best.. I know I need a 4mill crank, but which one, 115mm rods or 110mm rods? I also know i need a 68mm bore, will the Athena 392 kit work with a stroker set-up? Will it need a spacer plate, or can I run cut domes in my Pro-design cool head? Can I run a Pro-Design cool head with the Athena cyls? Right now this bike is 80 over with egg shaped cylinder walls and i'm not interested in repairing them, so replacement is the only option. ANY advice on parts would be appreciated.. I have had Suzuki's and Maico's all my life, and have only been into Banshee's for about two years.. I know what makes power for the $$$ on LT's and the old Maico 490's but am still learning the tricks of the Banshee trade! Thanks. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted March 4, 2013 Report Share Posted March 4, 2013 421 serval for trail riding 115mm longrod crank with blaster (573) pistons Quote Link to comment Share on other sites More sharing options...
Zillaguy Posted March 4, 2013 Author Report Share Posted March 4, 2013 trying to keep the entire build around $1000-1200, that serval top end is outta my price range. Quote Link to comment Share on other sites More sharing options...
BANSHEE HP Posted March 4, 2013 Report Share Posted March 4, 2013 everything is out of your price range then Quote Link to comment Share on other sites More sharing options...
n2otoofast4u Posted March 4, 2013 Report Share Posted March 4, 2013 trying to keep the entire build around $1000-1200, that serval top end is outta my price range. Find a new job or a new hobby Quote Link to comment Share on other sites More sharing options...
possum Posted March 4, 2013 Report Share Posted March 4, 2013 with that budget. ur gonna have to buy a good used top end and crank setup. stock cyl of course and it wont be a 421 Quote Link to comment Share on other sites More sharing options...
troyzstang Posted March 4, 2013 Report Share Posted March 4, 2013 Welcome to BansheeHQ Start shopping the for sale section. I would buy a set of used stock ported cylinders with some life left on them. (64.- 64.5 ) Also pick up a used hot rods 115 crank assembly . Order new 795 series piston and custom cut domes . Total build cost = Cylinders $200 / $250 Crank $250/$300 New Pistons $180 Bore $100 Domes $75 Misc gaskets / seal kit $100 There ya go Good luck Troy 1 Quote Link to comment Share on other sites More sharing options...
lil Doobie420 Posted March 4, 2013 Report Share Posted March 4, 2013 thats some good info troy when we going riding Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 4, 2013 Report Share Posted March 4, 2013 trying to keep the entire build around $1000-1200, that serval top end is outta my price range. Your only option for a decent 4mil at that price is to find one built in the for sale section. They pop up time to time. Just the new cylinders and porting with the crank alone are almost 1000. Then you need head, domes, seals, gaskets, reeds, clutch mods, minor shifting mods, exhaust, etc..... 1 Quote Link to comment Share on other sites More sharing options...
shustack Posted March 4, 2013 Report Share Posted March 4, 2013 y not build a +4 mil stock cylinder motor? a friend has a hjr ported +4 mil and it runs like a beast. Best bet is to buy used if your on a budget. 1 Quote Link to comment Share on other sites More sharing options...
Zillaguy Posted March 5, 2013 Author Report Share Posted March 5, 2013 That's what I was thinking was to go used.. I really want to go 421 on it, I have been watching ebay for used 68mm cub or serval cyl set-up... I have a line on a welded 4mm 115 rod crank for $250.00 or do ball joints on dudes F-350 (labor only of course). i already have full gasket and seal set, and 3-bond. I can do the bore/hone myself. So basically I need a used cub or serval cyl, a crank, and some new pistons/rings/pins/bearings/clips? I do most everything myself if i can, as far as technical and mechanical. i am a state of MI. and ASE master certified automotive and motorcycle mechanic, 18 years experience, and own Reliable Auto Repair of Wayne. I have been building custom cars and bikes my whole life but am new to banshees. Quote Link to comment Share on other sites More sharing options...
vulvafan537240 Posted March 5, 2013 Report Share Posted March 5, 2013 New domes too. And a new base gasket for a mono block cylinder. Base gasket/domes will determine your squish. What are your other mods and what do you expect out if this setup hp wise? Quote Link to comment Share on other sites More sharing options...
Zillaguy Posted March 5, 2013 Author Report Share Posted March 5, 2013 I am looking for a stout trail bike that will come out and go to Bull Gap/Mack Lake alot over the summer. This is going to be my beater, I can beat/break and not care. I was looking on ebay and found a Serval set up with pistons for $1100 new, and a crank that appears to be Chinese maybe, real cheap like $360, but i'm not sure about it. It's a 4mm stroke 115 long rod. Found domes for $60 and a tz maxload kit for $80. the shift star is modded, i have hinson basket, inner, and pressure plate, barnett clutch, pro design intakes no crossover or bullshit bottle, vf3's, 3/8's spacers, pro design head,fmf golds, but have a set of CPI in frames for this build. Also 28mm pwk's. Quote Link to comment Share on other sites More sharing options...
apeik Posted March 5, 2013 Report Share Posted March 5, 2013 Inc Wang crank lol Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted March 5, 2013 Report Share Posted March 5, 2013 i already have full gasket and seal set, and 3-bond. I can do the bore/hone myself. So basically I need a used cub or serval cyl, a crank, and some new pistons/rings/pins/bearings/clips? I do most everything myself if i can, If you do find a Serval cyl,don't bore it. Double check,but i think to even hone one,you have to have a special hone. 1 Quote Link to comment Share on other sites More sharing options...
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