EvilBanshee

Ya i think im going to go with 19cc domes on 112 octane. I know their is other ways to make power. But this is the easiest and cheapest. I dont ride enough to want to send away of juggs and have them re ported and all that sort of stuff. Compression makes torque! which is what i want.

I was hoping i could get away with 20CC Domes on 100LL and go to a 18 cc Dome for 112. I think their is a guy on this site that runs the same motor as me witht he same pipes and has 22CC domes and gets away with pump fuel. The amount i drive my banshee anymore ( 5 hours a year) ?? I think im gunna go balls deep and get 18 or 19cc domes and run straight 112 and order a set of SHEARER pipes for the thing. That will wake it up huuge.

Looking to add more power this summer. Currently have 22CC domes on my 421 68mm bore. Timing is at +5. I think i could run 20CC domes and be fine still with 100LL? ALso i might look into domes to run straight 112 octane as well. Would 17 or 18CC domes be perfect? I am at sea level. The port's are drag style.

Try new plug boots. Mine did the same thing.

I do believe it was done correct. My buddy has been a small engine mechanic for 35 years... Hes a very smart guy.

Thats exactly what i did. Pour'd oil down the head when the motor was a TDC. I ended up with 14:1

WEll in that case i should have no problem running 20cc domes with straight 100LL. Maybe i can even go down to a 19cc dome. ??

No idea what the head gasket thickness is. Its just 2 orings... I that the interchangeable billet head from VITO's. And dont we need to know exhaust port hight and all that shit? i cant remember what all that is...

9.68:1? Are you sure? I CC'd this motor before i installed it in the banshee. Me and my buddy came up with 14."?":1 (roughly 14:1) Static compression ratio i do believe? not dynamic. I forget which one we did. Maybe we fucked up lol

Ya ill have to get ahold of vito's. I was just curious to which Dome would be better. But if i only have 1 choice then my question is answered. Does anybody have a rough idea of how much more compression 100LL could handle? Like i said kicking compression im at 155psi. Compression ratio is 14:1. Timing is at +5 The domes i have are 22cc. I think i could easily be safe with 20cc domes. Im at sea level.

115mm long rod crank

i do believe the pistons in my shee are blaster pistons. 68mm bore. And my current domes are the 9 degree. I was just curious on people opinions on which angle made more horepower. I know for my snowmobile i bought a aftermarket head with interchangable domes that bumped up the compression and had a different dome configuration that increased performance by combusting more efficiently. I figured VIto's had the "OPTION" of differnt dome angles .

Hey guys, the weathers finally warming up here in CANADa. Looking to get a set of shearer pipes and bump up the compression more on my 421cc from VITO's. They sell a "13" degree angle dome and a "9" degree angle dome. I plan on going from 22cc to 20cc dome. But im not sure which angle would be better. I run straight 100LL av gas. Timing is at +5. Im at sea level. Cranking compression with the 22cc domes is 155psi. I think i can bump up the compression more and still be ok with 100LL. If not a Can get 110 or 112 octane. But if i will have to go 110-112 octane i would more then likely maximize to that and run 18 or 19cc domes. Your opinions are appreciated, From what iv been told the greater the angle, the faster the flame speed, the more horse power? correct?

WHo makes aND SELLS the "Shearer pipe?" My 421 is getting choked out by the FMF's....

What kit do you have? the 68mm big bore? Or their new kit? which is 66mm but can be bored 14 times? I have their old 421 kit (68mm, +4 crank) same carbs and pipes as you. Im at sea level, and have 22 cc domes, +4 timing. running of 100LL. I have 45 pilot, and 168 mains. I would bet you would need a 45-48 pilot, with 175 mains to start.

try a new set of plugs. And switch the plug wires around. See if the plugs look the same in each cyclinder. If they havent changed sides. Its not electrical. Could be a cracked intake or you have a vacume leak somewhere. 10psi difference should be that much of a difference in how it runs and how the plugs look.

x3. easily ultra 94 would be fine

Im supprised it hasnt blown up yet. 20cc on 93 would be pushin it..

Ahhhhh i figured you were megga rich. Glad u got it figured out

If your floats are'nt adjusted propper, You will starv the bike for fuel. I have done that before... It sounds like thats what happening. Orrrr it could be Bad Plug Caps, another issue i had, Once from 8000+ rpm, i would drop a cyclinder because i had a bad spark plug cap. Once i put on 2 brand new caps. The bike never ran better!!

I would Only change 1 thing at a time, if your Bike idols and starts fine. Leave the pilot for now. Play with mains. To mee, if it were to be lean, that ring no matter where it is should not be that dark. But lets be safe, throw 5 sizes up in Main. And do another run, it if runs worse, and your plugs are "blacker" (richer) Then you know your going the wrong way.

Make sure your Floats are adjusted propper.

Give me your set up? What domes are you running? What fuel? Any porting done?

Thats my expierences anyway.

Ok, i will agree with that. For trails only. They can work good. And yes, a single would be alot faster tuning.