pablopab50

Can you use Shearer pipes and Toomey T5 silencers? Is it bolt-on? Is it the same cascade clamp? Do I have to go down in jet

What does a pro mod transmission consist of? I thought pro mod and over ride couldn't let you compress...

Ok I guess every reputed builder knows this. Will do on my next order. What about my jetting?

Do you have the K&N part number? Last time I checked I couldn't find the right one with the angled boot to clear out Shearer's stingers

That's what I'm talking about! Thanks man.

Hi guys. The banshee was running pretty well but just wanted to have it perfectly jetted. Here's the info: 1) What type of aftermarket exhaust do you have? Shearer small bore inframes 2) What type of airfilter do you have? K&N pods replicas with outerwear 3) Are you a)running a stock airbox with lid stock airbox with NO lid c) Stock airbox with vents d) no airbox at all: No airbox 4) What is your elevation? Ground sea level 5) What size pilot jets are you using? 58 6) What size main jets are you using? 160 7) What temperature is your Banshee jetted for? I assume for fall temp 8) Do you have a port job? "Drag Ported" 9) What kind of carbs? Keihin PWK and V-Force 4 reeds 10) What size carbs? 35MM

Ok ok hold on all of you duners and drag people. I understand it's a bit overkill for the stock transmission a ported 421 cub BUT could it still work? I have the wrong motor for sure but I really want to shift it with the clutch just like a standard banshee. So I really want to avoid modded transmissions. Would with a Driveline performance dune/trail kit + straight cut drive gear + billet basket + lockup be ok for trail purpose? My transmission is top notch (for now ) and I have a modded shift star. I did not noticed any misshifts or any trouble shifting at high rpm. The point of this thread as mentionned in the beginning, could it still work even if it wasn't meant to be used in 85hp+ bikes? I don't drop the clutch at high rpm in dirt nor on asphalt. So imo the only way I can ruin it is clutchless shifting or repetitive drag racing. Has anybody here with a 421 serval or 421 cub with at least 80hp ever used stock unmodded transmission to cruise and still go fast with their bike? Thanks

No need big carbs unless you have a cheetah cub or serval 421 or bigger. As suggested, a pair of 28 PWKs would be perfect. Single carb is meant for single cylinder!

I think I will be going +2 as suggested by trickedcarbine. Trail riding is the main purpose of the bike but a longer swing arm will definitely help for drags and hill climb. Thanks. I was thinking about F.A.S.T. custom made swing arms. Any other known good round house swing arm maker?

I see. As you said earlier, stock lenght is good but will a +2 be bad? The reason I thought getting longer was to be able to drag or to hill climb someday without flipping the bike. So after all, stock would be the better option?

Do you guys believe in OEM's swing arm strenght for a 421 cub?

For real? Damn allright...

I only ride trails with my 421 cub. I weight 150 pounds. Should I get a +2 or a +4? I like corners.

Bruuuuh

Here is the result of the pilot jet change to 58, middle position. https://www.youtube.com/watch?v=BnZejCCoOMo I think it's just perfect. Obviously weather is cold and might have to change them for summer. What you guys think? Main jet is 160. 35 PWKs

By "blowing a plug" I meant burning. The plug either was badly fouled or it stopped working because I heard a bigger spark in the cylinder and in my opinion it's not from pre ignition. Right after 2 similar big sparks, the cylinder died. Issue was fixed by changing the spark plugs. Now obviously the temperature is way colder but as mentioned in my last post I changed the pilot jet so I would safely guess that the engine should be less rich and thus burn the gas better.

Pilot jet was 68, tried 58 and 1 and half turns out and idle sounds good. Needle is set to middle. What you guys think?

Well I blew one spark plug, it made a PAK pik and then the cylinder died. Changed both spark plugs for new ones and ran like new. But obviously I was running lot of oil at first 30:1 and then 32:1 Now I'm maybe around 34:1. I used to run 36:1 in my stocker and it was perfect. But I'm still in the breaking in process as for the 421. I don't know my pilot size. I know for the main you can just unscrew the bowl and you will see the main but as for pilot and needle I guess you have to completely take it appart? As for the black knobs are you referring to the fuel screw? Off-subject. Damn those shearers suck in trails. Powerband starts at 6700 or so. I knew I should have bought CPIs. I have exhaust leak where the header mount on the silencer tube. I ordered cascades clamps. I'm using for now my old FMF rubber clamps but they do not completely seal. My head, cylinder, case, carb is all black from unburned fuel

Here is one of the firsts start ups. When I press the chokes down you can hear the slow idling for few seconds until I slightly push the throttle to keep it running. https://www.youtube.com/watch?v=3jKcqnau180

Allright, I ran 160 mains, and the air screw is almost all turned out. Do I need a bigger or small pilot? The idle is way too low. But giving just a bit of gas and it sounds good. The needle seemed ok (position) but how are you really sure if it's not too lean or too reach though... I got used to determinate whether it's too rich or too lean by the ear... Like I said at idle it's clearly too rich in my opinion cause it even stalls. And could it be the fuel screw? ( GROUND SEA LEVEL ) It was 50deg F With Pods

For those who have the same issue as me to hold the Shearers tight. OEM and FMF Toomey springs are too short. That's why you break the cheap FMF and Toomey springs. OEM are stronger though. I took springs from a 2002 Yamaha SX Viper and they fit perfectly.

So you guys recommend either 23cc or 24cc

Correct. I wouldn't say a little more lol. I paid my 5US gal for like 115 CAD tax included which is like 90 USD. Here 5US gal at the 91 pump would be about 20 USD. With a cub it's a complete tank each ride... So it's pricey as hell.

Yes you are right. I might just run pure race gas untill I get bigger domes. You remind me of my buddy who had huge piston slap and just redone the rings instead of having the cylinders rebored. He went cheap way and it blew a month later. Jeff at F.A.S.T. told me with 22s I could run pump. Again let's say I reach 160 PSI. I could still add some octane booster to raise it up to 100 right? I just read that every motor are different and a 160 PSI on a stocker is different than on a cub. So your 150 PSI magic number kind of makes sense. But isn't 150 PSI on a big motor such as the cub really low? Am I being a bitch or a poor ass boy and should I just open my damn wallet and spend the extra hundreds the cub needs in gas? Is it okay to run pump gas on a cub first of all? lol... If you saw the pictures in the second or third page of this thread, you can see it's ported. So, do the cylinders as they are require higher octane gas to perform well? I also just don't want to have to replace the rings 2 times per season. I'm not into drag like I mentioned previously and I don't care if I loose 10 HP. The motor probably already have at least 80 horses. Gotta love the struggle of built 2 strokes