00tbanshee

on my 421 cub i am running one row of balls with heavy springs.seems to work fine

see if there is a spacer plate on the top or bottom of the cylinder more likely the bottom if not pull the head off if the piston comes out of the cylinder about 2mm then its a 4mil

not sure about the rotation mass but i would run the slingshot.i run one on my 4mil cub and it works great.

my buddy just had one do the samething.it only had a couple hrs on it and it was a fresh topend.everything new even a fresh bore.the only thing that we could think that it was a bad wrist pin bearing from the factory.needless to say his one cylinder was junk after this.

slingshot is really nice.thats what i run.kevin at herrjugsracing.com sells them.price is good and you don't have to worry about extending your clutch cover.

you will be more then happy.like was said you might want to think about a +4 swinger once you get it together.let us know what you think after your first ride. :thumbsup:

get ahold ofkevin at herrjugsracing.he is a great guy and really easy to get ahold of.also you will be more then happy with the performacne when its done

i have a 421 cub for strickly drag racing from HJR and have to say not one regret.its a runner

will not have any problems :thumbsup:

kev for sure knows his stuff about these motors.glad to see another happy customer.fran you ready to go tear the dunes up next weekend.i can't wait.wish it was today that i was getting on the plane.

its depending on what kind of port work you want done.but kevin at herr jugs racing has i think the cheapest prices and does awesome work. do a search on here don't think there has been anybody disappointed with his work and there is alot of his work out there.let him know butch pointed you his way

the slingshot is also a lockup but its just nice cause you can get it to go under your stock side cover with just alittle cutting

some of them bolt right on your outer pressure plate and ones like the under stock cover "slingshot"which i run, takes place of your pressure plate.all the lockup does is put pressure against your clutch to cause it not to slip.the faster it spins the more pressure is aplied

can say that i have ever seen one of white knuckles motors run but as for kev's i've rode a few counting my own.his motors are top notch

here is HJR site.don't be affraid to give kev a call.he does awesome work,turn around time is one of the best if not the best and costumer service is great.http://www.herrjugsracing.com/

i ran set of of 34pj's on my 4mil stock cylinder last yr and loved them.the idle was fine.everybody says lectrons but i never tried them.this yr running 41 mikuni's from k&t.they work well

tony, kev knows what you are going to be doing with this thing.he is a very smart guy.i'm sure he will port the cub so it will makes the power where you want it.there is many things he has learned about these cubs and i must say that they work.as for a overide they are great.i have a 1-5 neutral down dunable but for the type of riding you do you just have to remember that they still shouldn't be back loaded at high rpm's.as for the lockup.the slingshot works very well but you need to remember to lock tight the 6 allen bolts or they will come out.believe me.lol.if you are going to run a lockup then its a good idea to have a overide

+4 with one of kev's 421 cubs is going to be a handful.but you will like it for sure :thumbsup:

for the hp numbers you will have to ask kev.if i'm not mistaking his 4mil stock cylinder drag port made 90hp.which i had the same motor last yr and it hauled ass.now my 421 cub kev did this yr for me is alot stronger.if we had a dyno out here i would have it done just to see how much more hp it makes.both motors run awesome and are very reliable.

i've rode acouple different setups kevin has did and they all haul ass.he knows his stuff for sure.glad you are happy

i run a 421 cub drag ported.for me i think its a very good setup and i weigh 235.as for it comparied to the bigger strocker cubs i run right with them.but like was said it is all about the setup.

does the plugs look the same on each cylinder?

go with what you builder says.he knows best.the bigger carbs are for the all out drag racers.33mm is more for the dune motors but i did run 34mm on my 4mil drag port motor and worked really well

like was said by kao.there are many good builders out there but i did the same thing your doing and searched for days and i found kevin herr.i have ran his 4mil drag port with stock cylinders and now the cub.his work is awesome and his costumer service is out of this world.his motors run with any builder and alot of times found myself out front.i know it was said that you will here the best is from the guy that did there motor but in my case i go with the guy that builds a motor that wins me races and thats why i use kevin

ohtsu's is what i run.never had any good luck with my prowedge tires on a hard dirt track