2003LimitedBanshee

This sounds really bush league, hokey, but, when you are running it pull your choke out to the first click. If it runs better you are prob a touch lean; you could be right on that ragged edge where it will run forever and be making peak power and never burn up. This is just to get you in the ball park. Those plugs look pretty light to me, but I'm not a Keihin guy so I don't have a lot of good recommendations as far as sizes. I'm more of a fan of long term color than plug chops and then just a good riding feel. If everything is jetted/tuned right, you should have good pull from all throttle positions, you should never foul plugs and the color should be right. Despite all the negative things I hear from my 4 stroke buddies, I've never fouled a plug or burned mine up once, and I'm making more power than any of the crowd I run with thinks about making... :biggrin:

HAHA! Now that's some funny $h!t !!! Thanks BoostedRex, can't wait to get them! If all go's well, I'll be pulling them on the dyno later this week compared with my T5's and then duning them in a couple weeks!

Pretty much everything has been covered already and looks to be pretty good info. The only thing ned mentioned that I wanted to clarify, is that longer shocks will be almost impossible to mount with the banshee spindles, because typically you will not be able to compress the shock that much, to get it installed. Also, in my experience (I've done a few :happy: ) with the longer shocks, they do reach a point where the stock brake lines aren't really long enough anymore. Just my $.02

You rock! That's the one!!! I know, when I found the bare CPI's I knew that would be good to ceramic coat, but remembering his bike, made me want to run them bare for a while. That is, assuming the come looking as clean as the T5's do in his sig!

Just like the title says, I've seen postings from a member with a Black and Blue plastic banshee with bare T5's in his sig, but I can't remember his username or where I've seen the posts. Anyway, I just picked up some bare CPI's and I was really digging his bare T5's, wondering what he used to coat them with to keep them looking awesome. I will probably have mine ceramic coated at some point, but was thinking of keep bare to start. I know this is about exhaust, but it's not really jetting/exhaust question related; really just looking to find member and figured this forum gets viewed the most... Thanks! - Brian

Thanks! Yeah, they are still in the workup phase. The intakes haven't had any timing changes yet, so they haven't had the final smoothing put on them; still kind of in the rough in phase. I've just cleaned up the transfer runners at this point, no timing changes. My dumby rotating assembly should be here this week, so it will keep me from having to tear down my bike to use as a rotating assembly for degreeing. I think you will be very happy with them when all is said and done!

Woohoo!! Looks like I'll finally get the chance to join the CPI club and see what all the fuss is about! Thanks BoostedRex, I'm throwing my bike on the dyno soon, so this will be awesome to compare the two pipes! Thanks! - Brian

Absolutely, if you're still game... Shoot me an email with shipping and I can mail you some cash and they can pass in the mail?

Thanks! I'm still dialing in the jetting on it, but mostly the off idle and midrange. It pulls really hard now and cranks up the RPM way faster! With the stock swinger, on the country roads I have to test it out on, I actually can't really hog full throttle on it because it will yank the front end up, pretty violently. It has a very noticeable hit on the pipe, but the hit comes early and pulls through the RPM. I've been hanging out over on PlanetSand a little more lately and several of the builders I have been talking with have recommended I try much more aggressive port timings. So, after I finish up the newest set of cylinders for another HQ member (who graciously offered them up for me to practice on) I'm going to start in on my other personal set of cylinders and give them a more aggressive grind. The other HQ member's cylinders should rip as hard, if not harder than my current ones, as the transfers are worked much better on these than on mine. I did a pretty decent job on mine, but I did a lot more looking and thinking on these, as to how much I could remove and where it was most effective.

Okay, got a few more pics of the build on my cylinders and a couple for another member here that I am just starting to work over. Checking the ring end gap and a view of the hone: Another ring end gap: A few of the cylinders I am starting to work over now. These cylinders should run even harder than the ones I did up for my bike. The transfers are worked over much more heavily and opened up better. I still actually want to open them up more, as they kind of narrow down as the runner approach the window. I think they look okay though. Waiting on my mock up rotating assembly to use for degreeing. Anyway.... Couple intake pics: Transfers (just starting):

Have you checked the resistance on your plug wires? It could be that the plug wire on the left side is breaking down and it doesn't fire properly under those throttle conditions. Also, have you checked your float height, especially on that side? It could be that your float height is too high and it is feeding that cylinder with slightly more fuel, the bike just better compensates in the upper RPM's, as far as the smoking is concerned.

So far the little bit of riding I have been able to do, it rides pretty nice. I've only had the chance to ride it up and down the paved road, just since finishing my porting. It doesn't seem to ride very stiff at all and you can see that the suspension is active as you are riding. I am going to make a quick day trip over to the dunes this weekend, mostly to rip on the new porting, but also to test out the suspsension. Another side note, I think I am going to add extended brake lines with this swap. With the traditional 450 swap, brake lines are not a necessary upgrade, due to the decreased ride height. However, with the added height and width that you already gain with the 450 swap, it puts a much tighter line on the brakes than I would like.

For you there would not be, in fact it could cause you issues. The banshee a-arms are canted up out at the ball joint end and the spindles are angled to match this. Thus, with the 450 a-arms (not canted up) there is a small angle mismatch between the a-arm and the spindle. This is not an issue at all running the stock 450 shocks, but limits travel with 450R shocks or shocks in between 450 and 450R lengths.

Thanks swr! Where is eagle creek by the way? I'm down in Ashland, near Medford at the south end of the state. I honestly don't remember if I have a set of V-blocks, if I don't I can come up with a set very easily from some friends that run a local engine shop. He mentioned checking to make sure the crank is in phase, but didn't say how or how to adjust it if it is not. I would assume you could check phase as I described earlier, before you split everything and tear it down? I suppose I should also ask if the general opinion is that I should really consider trueing and welding at this point. With my porting on the cylinders I would hope for at least low to maybe mid 60's range. Knowing that really what is being checked is the runout, I would think the trueing is actually more critical due to the added RPM potential after porting, as opposed to the HP itself. Now, I can see though how the extra HP and load on the crank makes welding all the more critical so that it stays in phase etc.

It sounds to me like you prob need some PC's (never ridden them myself for comparison) or some T5's or something. I've ridden my T5's for many years now and still love them. For some reason there are some anti-Toomey crowds, but when I ask around among many different crowds, T5's commonly get a nod for the best all-around pipes. They retain good bottom end and still pull fairly strong up top. My guess is Snop has compared the two, so can probably offer a first hand comparison.

Snop prob has dyno sheets to back up what he was talking about. My guess would be decreased output across much of the RPM range. You could probably smooth out your hit with some more midrange oriented pipes like T5's or some Fatty's or SST's. Just when I think about the two stroke pipe theory and having both cylinders pulsing into the same expansion chamber, I can't really figure how they would work right. Just my $.02 EDIT: Doh! Beat to the punch by the horse himself... I.e. from the horses mouth...

Okay, so I've been around forever, and used the search, so don't go blasting me... Seeing as how I just ported my cylinders and I expect it to lay down respectable figures, I was thinking I should consider trueing and welding my crank. Question is this: When everyone references having the crank trued, I assume we are talking about making sure it is in phase? The reason I ask is because this would be easy enough to check with a dial indicator and a degree wheel. I could also spin the crank, but I've never heard a specific reference to having the crank balanced. If all that is done is checking to make sure it is in phase and then TIG welding the pins so it cannot come apart or out of phase, this seems accomplishable for me personally. Thanks!

Technically a plug chop, is what a lot of people swear by for checking jetting; that should be done on a set of brand new plugs. However, I prefer seat of the pants and plug color. If I had my absolute choice, I would use a dyno and air/fuel ratios to really get it right. Not having that available, I go with how it feels in the intermediate throttle range, under different loads and throttle positions and then look at the color for the main. I use the same method for checking color as is described for doing a plug chop... Wide open in 6th for 10 seconds, pull the clutch and shut it down immediately. I aim for a light chocolate milk color. But, as snop said, type of fuel and oil can affect the color you will see.

You might get blasted on this one, but I am not a 250R guy so I don't know for sure what they had stock. This is one of the stumbling points amongst many people. Just because it has a higher compression PSI, what your gauge tells you, doesn't necessarily translate into compression ratio. My point is, there is a difference between cylinder pressure and compression ratio. As I said, I don't know what CR 250R's had stock, but if you were to say they have higher cylinder pressures stock, that I could agree with, but they may not have a higher CR than the banshee. Again, I DON'T KNOW WHAT STOCK 250R CR IS, I'm just more trying to illustrate the theory. Another example, my 283 in my 63 Nova had about 220 psi in rough figures from what I recall, but with a CR only in the upper 8's. Point being, I couldn't say I had a higher CR, but I certainly had a higher cylinder pressure.

Both of those changes affecting your port timing, in both cases giving you a longer duration. Did you actually lower the boost port opening, i.e. grind on the sleeve, or did you just open up the runner leading up to the port opening? I don't think you've done anything that should hurt the performance in any way, but keep in mind, you're only working with 54mm of stroke, so small changes translate into much larger degrees of crank rotation changes.

Can you make the picture any bigger and possibly a little lighter? But from what I can see so far, it does look pretty narrow. As far as the chamfer on the ports, I used a small file to work them. I don't know that it is as critical on the intake side to wrap the chamfer down on the edges running perpendicular to the rings, due to the bridge keeping the ring from flexing into the port as bad. That being said, I did chamfer mine a little still, just to be safe.

I'm going with no... Considering a NOSS head, even used would be half that price and he's got some bitchin' looking head on there. Oh yeah, and it says right above, what is included. Bump for a good guy!

Have you looked at your plugs lately. You've just described a couple classic lean characteristics. It could be other things as well, but jetting is my first suspicion. You didn't mention your airbox/filter setup, which is needed to get a better idea on your jetting. Even with a box I would guess you are a size or two lean. Also, which FMF pipes? I'd check your jetting before ripping it again, otherwise you may be moving up another piston size. Since you've had it apart, I should mention that an airleak could also be the source of your lean condition; good probability there too.

I assume you must mean, fresh 64.00mm jugs? Just have to keep your eyes open. If I remember right, these cylinders I just ported, came from a guy who ran them for just a little bit and then pulled them for a set of cubs. As far as I am aware, Yamaha isn't still making cylinders, so, as time passes, virgin bore cylinders will go away. Nothing wrong with a set of cylinders that may need a light bore and hone though.

Exactly, use your base gaskets, torque the cylinders down etc. just like you were going to run it. If you don't you are going to be getting inaccurate measurements. Also, I personally am running the Yamaha base gaskets, they have an absestos, although we know it isn't, like covering over them. Other than that, the bike is running strong! I am going to drop down t 350's on the mains, I have a set of 27.5 pilots I picked up and it acts like it may need the needle dropped one position. But, I am going to wait until I swap the mains, then see how the mid acts. I think I am going to make a run over to the dunes next weekend, about 3 hours away, for a day ride shake down. I've still got a few more pics to post up, but I've just been really short on time lately.