trickedcarbine

Agreed on the on the tranny. Mine is like friggin butter. I ran it all last weekend without a missed shift and if I do it right under power I can shift it like an override.On the traction though...,, have to dissagree. Remember there will only be one tire and it's half as wide and only partially in contact with the pavement. Lotta guys out there with modern banshee cylinders(ie. Cub) and traction is the first issue most of them deal with. So, OP. If you do go that big on the motor, remember your chassis has to be just as up to par. Wider swinger conversion for a fat Michelin, custom shock, etc.

Great Jay, give out all the secrets! Next you'll be telling every body about the drippy dick I got from that fat chick at last call.....,

Jim Smart @ Passion Racing Rodger @ Wicked Motorsports Nate McCoy at McCoy Motorsports. John Stallworth @ JSR (several pikes peak titles) Kevin Gigot Stephen Rothwell @ Two Stroke Shop (Wayne "wobbly" wright is no longer a partner) You don't need much more then 80 HP in a light weight chassis to compete with 600's. There have been a few fellas in the sport bike scene to pop up on BHQ from time to time that took to the banshee platform and really did well.

Only a select few guys I know that I would trust with a gp style platform. I will pm you later in depth with details

Problem with a supercharger, parasitic loss. On a big car I think it is ok because it makes so much power it's probably worth it to whomever is doing one. On a Quad it means lots and lots of Stuff to be stuffed in the frame rails and custom machined plates and adapters. Lots of money and it seems like it would need half of the power it can produce to turn it self. Ever hear of cranking loss? Like when a banshee has so much compression it is fighting itself to turn rpm's on the big end? About the same effect on a supercharger.

Not really a definitive win, just an open day, but it walked on anything on the frozen water. Note, typically the bikes are outrunning quads, not my little ol banshee though.

Again, many twin snowmobile engines much larger then our banshees have done very well on a properly 2/1 intake. The majority of banshee 2/1 intakes have a huge choke point where the air is decided since many of them are designed to be short enough to still use the air box if needed.

Exactley what I found, can I get a copy of that tuning bible when I get ready to play with the Q series fuels or the MO2X

Hmm, something isn't right for sure then

Awesome!

Current set up is 34mm pj's and Rockets

So, when you gonna put them together! Been years.

Also should mention this thing is quite a bit more ballsy then even my old 440 big bore with similar durations and heights. If you've never had a 12 port cylinder from Jim in your hand it's hard to grasp how nice it really is.

Yeah cam, a dune ported HJR bike and an A&S bike. The HJR chassis was a little weak though but the A&S bike had pretty comparable set up and we ran on dirt roads. Seems like the A&S bike would have been ok had it been able to come on sooner. On a track like we ran today it might have been a bitch to fight it off, but the thing is not all our tracks are big half mile ovals. The last actual AMA event I raced was a thrown together little track that I couldn't get out of 4th on. So a bike that is built to kill on the big tracks would be Screwed. So after doing this for several seasons, I can honestly say this is the most impressive all around motor for my particular type of racing. People seem to forget that the good name Jim did have was built on setting up short track motors. Why send your wave runner to a lawn mower mechanic? Why send your truck to a carpenter to fix the motor? Jim has sent many motors out for Flat Track/TT racers and several of them have brought home the trophies. So it made sense for me to have him build my motor. I've been around BHQ since 04 and had my banshee a cew years prior to joining so I have seen and had a few set ups that i liked or didnt like. And so far with this particular combo I can not be happier. That said I can still squeeze a little out of her with 35's and shearers and I'm sure there could be some decent gains.

I'd imagine for asphalt racing the motor size isn't so much the deciding factor. You probably don't NEED them till about 100+HP. However I you run long stretches like quater mile they would benefit you to help give you more gear

Ran that C14 today. It definitely required even more jet then the C12. Normally the motor would be ok in the 160 area. Today I wound up getting the best results with a 165 main and my CEL needle all the way up, and a 62 pilot. Part of it could be the port work in my bike though, this thing takes fuel like drag bikes do alky. It's like you can just keep throwing fuel at it and it will use it. I had wet plugs at about 168, so I leaned down the the 165's and it seemed to feel a little crisper though.

Oil mixing with coolant makes the sludge! Get the cyls decked the next time you rebuild. Then step torque the jugs to the head befor tightening the cylinder base nuts down.

It seems that many people are beginning to think very negatively of Jim from Passion Racing. Especially after his joint venture in the sniper exhaust. Let me just say one thing. Jim and Gary are two totally different people and have two totally different attitudes. Jim has some of the most flawless port work I have ever seen and the motor has done everything it was promised to do. And when it comes to his engine program, he is actually incredibly talented at what he does. I know that is contrary to what people wanna believe but after getting to finally run my new set up from Jim on the ice,I am a fucking believer. Today I ran the bike on a true half mile oval track and the bike just kicked ass. I ran down all dirt bikes that were there and the other banshee as well. The 2 wheel machines included a built early 400 similar to what Doug Henry pioneered the AMA with, a newer Honda with 490 big Bore, and a 600 XR powered bike. The Passion motor made plenty enough grunt to pull out of the turns with minimal clutching if any. It pulled the heavy 20 inch tires with 440 cutters in each tire on 15/39 sprockets and ran out of gear well before the end of the straight lap after lap. Never have I had a motor that let me get in and out of the throttle so easily. This thing just let's you goose it right out of the turns even if I missed a gear or got to wide in the wash. I just cant get over how all the bikes there would try to pull the inside line thinking it would hold the banshee back but the motor just let me take them on the outside and then walk away on the straights. As far as I'm concerned if you need a flat track motor done, Jim is hands down the guy for your engine set up. I Havnt had a drag motor done yet but I think I may give it a go with Jim on that as well. To all the naysayers out there, either give him a motor to work over and see for yourself, or keep your uneducated opinions to yourself.

Yes, the axle is a direct swap. But some guys have actually got even a few more inches narrower by taking the hub and flipping it so that it mounts the wheel inward.

These motors are pretty simple little puzzles to put back together. Just get a manual and you SHOULD be fine. As far as Porting, there are a multitude of builders on here. But you did post this in the flat track section so I'm guessing you would be best suited with a builder who knows that type of racing personally. There have been some lackluster results with HJR motors lately especially in the flat track/TT type motors so don't let that fast turn around time lure you in. Besides he does drag and dune motors not Short track stuff. My vote, get a 4mm 12 port set up from Jim at Passion. A lot of guys talk shit about his pipe venture with some idiot, but his stock cylinder set up is second to none. And he made his name doing the flat track motors for banshees. Mine is Bitchin!

Cub would be great on open roads! You could definitely do an 80hp stock cyl with some sort of dune type port and have a great all around motor. But in my opinion you would have to be on race gas to make it worth it and you will be on regular roads that have regular gas stations that sell regular fuel. If it were me I'd do a pump fuel cub. No bigger then a 4 mil though because you will be opened up for a lot of long periods on open roads. The motor would be a totally different beast then some trail, dune or drag set up. The lower compression for pump fuel would put you at a high 80's motor and let you get away with the sustained high rpm's of the street. Gear it out to. Maybe get your self an RZ350 tranny and have it cut to handle the shifting under power. Get your self a virgin cylinder, have it ported, and plated here in the states. Get your builder to set up a complete package before you start assembly so you only wait one time.

Do a 4 mil and be happy happy happy....... (duck dynasty) you are already in need of a new crank so go for it.

If you are referring to the 440 manifold go ahead and run it. If it is a trinity or chariot you are fucked and will regret it. There really won't be much more fuel economy. The bike will just pull almost twice the fuel through he carb. I think if I were you a 38mm PJ or even a 39mm PWK would suffice. I have seen a few 2/1 and MOST are garbage. But there are a few trick set ups that do work. Also stick to the E series needles on them or you will get a weird midrange hesitation and sputter

Pshhhaahahahah! What the fuck! So if I rattle can my old stock parts they are remanufactured? Sadly the auto business has suffered hundreds of shops who push used shit that has been painted as reman stuff. FAIL!

You are positive that you were given a "Serval" cylinder? You measured the port heights? Your original post just sounds typical of a regular Cub cylinder. But, it should have low end for sure if it is a Serval. I think you could be runnin the wrong pipes for starters. Are they small flange small bore? Also, take apart the carbs and let us know what jets you have. Pilot? Needle and clip position? And main jet? Also snap a pic of the spark plugs and use the mobile photo bucket app to upload the photos.