421 Cub

[TeamRealtreeHD]

I am putting the 421 in the bike this winter, and had a few questions for the guys running them

 

Kevin is going to set it up to run a 50/50 mix. I don't want to run straight race gas, but 50/50. I am going to run a 58mm stroke (+4mm) with the 68mm bore obviously. He has a setup already to taylor my needs with exhaust heights and the ports as well. Switching to Shearer inframes as well.

 

I already got the direct drive lockout clutch and the cool clear lexan cover.

 

I am getting a +4 swinger as well, with the longer chain, brakeline and all the rollers and guides.

 

My question is, with that said, what else am I going to need for this setup. Right now I can't think of anything, but was wondering if I missed anything to have this setup run properly and safely.

Edited September 9, 2008 by TeamRealtreeHD

[Michael Jackson]

some decent suspension to get that power to the ground meanwhile allowing you to ride for more than an hour without getting beat to hell!

[BellicoseBanshee]

Be sure to use a TZ bearing on power side of the crank and you will definitely need a Pingel fuel valve. A billet fuel cap with the vent hole drilled out to about 1/8 inch to aid fuel flow. You may also want to have your rear shock serviced to match the increased swinger length. The usual transmission odds and ends as well...

[TeamRealtreeHD]

A pingel is a must for sure.

 

I plan on doing some tinkering with the tranny as well.

 

Any other advice would be greatly appreciated.

[docjcwatson]

Carb size?

[mawcusb]

Carb size?

X2

[TeamRealtreeHD]

33's for playing around. Kevin said they will do just fine for the time being for the motor.

[bada450r]

I am putting the 421 in the bike this winter, and had a few questions for the guys running them

 

Kevin is going to set it up to run a 50/50 mix. I don't want to run straight race gas, but 50/50. I am going to run a 58mm stroke (+4mm) with the 68mm bore obviously. He has a setup already to taylor my needs with exhaust heights and the ports as well. Switching to Shearer inframes as well.

 

I already got the direct drive lockout clutch and the cool clear lexan cover.

 

I am getting a +4 swinger as well, with the longer chain, brakeline and all the rollers and guides.

 

My question is, with that said, what else am I going to need for this setup. Right now I can't think of anything, but was wondering if I missed anything to have this setup run properly and safely.

gearing will also play a big roll........you want to gear it probably 14\41 or a 42 in the back....imo the cubs are a topend cylinder so you want to play with your gearing a bit..........this is how i see what youre doing .....you're trying to stuff a ls1 motor in a minivan so dont be to disapointed when it doesnt do so good in the trails or just simply dunning it.........it will be a work out so you will have to probably make up for it in supension .......have fun

[Titan up]

I think you could go bigger on the carbs. Your 33's might help the bottem end and have a little more

snap, but that cylinder and set pipes would benefit greatly having more air fed to them with the

bigger carbs.

If you don't already have one, you might consider a modded shift star and the "shift pro kit" that Cascade sells. You don't need an overide either, my bike shifts fine with this mod.

[locogato11283]

i think id stick with the 33's. youre gonna have tons of top end as it is.. youre gonna need all the bottom end you can get.. ive always said, and others will agree, that cubs are NOT trail friendly. add shearers and you have an even less trail friendly bike.. i really think that you would be better suited doing a stock cylinder 4mm motor ported for your style of riding.. i think this cub motor is gonna wear you out in the trails. and i will also say that i think it doesnt make sense to de-tune a cub motor.

 

just tryin to give you some honest opinions from someone who had a 4mm cub and now has a 10mm cub.

[TeamRealtreeHD]

i think id stick with the 33's. youre gonna have tons of top end as it is.. youre gonna need all the bottom end you can get.. ive always said, and others will agree, that cubs are NOT trail friendly. add shearers and you have an even less trail friendly bike.. i really think that you would be better suited doing a stock cylinder 4mm motor ported for your style of riding.. i think this cub motor is gonna wear you out in the trails. and i will also say that i think it doesnt make sense to de-tune a cub motor.

 

just tryin to give you some honest opinions from someone who had a 4mm cub and now has a 10mm cub.

 

I am still considering the stock jugged 4 mil, I got a good deal on a set of cubs though. Really good deal.

 

I don't trail ride at all with this machine. Not one bit. Maybe a 2 minute ride to get from my place to where we ride, but that's it.

 

I am still considering my options.

[docjcwatson]

You ride the coal hills and that right? So I seen that one video where that one dude was tearing it up like half throttle and what not. If your just hill shooting and what not, do the cub. You'll like it more. Your going to be playing around a lot more like that one guy, I say stick with the stock cylinder.

 

Oh, and I would say that the carb size depends on your top end. locogato made a good point. A cub is a top end bike, so go bigger carbs.

[TeamRealtreeHD]

75% hillshooting, 15% playing, and 5% drag racing

[docjcwatson]

Sounds like a cub to me man!

 

Just do it! Wow, that sounds so much better on the commercials. :shrug:

[TeamRealtreeHD]

Yes, I am going to talk more with Kevin about it for sure. He thinks it would be a good motor for what I do, I don't play like alot of guys do. Mostly hillshooting, with a dune and play put in here and there.

 

Shoot 3 or 4 hills, let it cool. Repeat. Then maybe dune. And throw in a drag race against some four pokes and that about sums it up.