2003LimitedBanshee

If you'd like to contribute to my learning, I'd be happy to grind on some cylinders for you! :biggrin: :biggrin:

Exactly, Dan was telling me that it helps with scavenging in the uppermost portion of the cylinder. I'm no flow expert, but I can invision in my head, with the angle of the bust port that it would force fresh fuel/air into the top intake side of cylinder and the exhaust out of the cylinder through the exhaust. I believe he said this also helped to decrease short circuit between the transfers and the exhaust. Again, I probably would not have been smart enough to figure that out initially, but it makes sense in theory. I think I'm already hooked on porting. The work is fun enough but the theory behind it all is the best part!

No problem on the spacers, I'm glad they worked out for you! Yeah, without the baseline specs to start from I would have been dead in the water. Definitely go and check out Gordon Jennings Two Stroke tuners handbook. It will take you some time to absorb a quarter of the knowledge and theory that is in there, but it is GREAT info. When I originally picked it up I took it with me on a couple long road trips, where I was not driving and just read and read. Haha, porting for cash... maybe. I need a lot more understanding on theory and just sets of cylinders to feel confident in it, but I suppose it's possible? EDIT: Almost forgot, IMHO get some good tools if you are going to do it yourself. But, by doing that, you will be into it more than sending your cylinders out. For me, it came down to being able to say I'm doing/did them as opposed to the money spent. For instance, I know of some members back in the day saying all you needed was a dremel, but with my Foredom motor, it has a heavy cast foot pedal that controls the motor speed and makes the tool much more controlable! WOW, thanks sheerider! I don't think I am quite to the confidence level to start cutting someone else's cylinders, but hey if you'd like to let me practice! :biggrin: For now I'm going to run it with my T5's, probably bump my timing up a degree from +4 currently and go to at least 19's in the head, I bought a good used set a while ago, but I might go smaller yet at some point... I can already see that I'm going to be cutting on my cylinders once I pull them off to swap these on. Then like the addiction was at the start, it will go from there with pipes, carbs etc!

Thanks! You're post and questions are what got me on the ball again about grinding. For some reason that provided the spark and I just dug everything out and started in. I think I was over complicating it before when I was avoiding it. It's actually not all that hard. NOW, I had specs that were recommended to me, all I had to do was understand how to produce the specs, but knowing what and how the specs work are what you pay for with the builders, the knowledge. The theory makes sense to me and because of that I think I would have a pretty good guess on where to go from here as far as altering the timings more or differently; but, if I didn't have a baseline it would have been impossible to figure out where to start. I'm finding I need a couple more burrs, so that has slowed it from completion, but more or less one jug done in two evenings. I feel pretty compitent with hand/power tools so that definitely helps and there is DEFINITELY a learning curve in figuring out what speed to run the burr at for any given desired result.

My response is always as little as is minimally required. You want everything to be fully lubricated or you could rob horsepower through added friction, but beyond that you are just robbing power as oil does not burn and produce power, it simply aids via reduced friction. Personally I run Golden Spectro synthetic/peteroleum (regular oil) blend @ 50:1 A ton of people lean towards 32:1,b ut I have run mine without problem at a much leaner ratio will no ill effects. Now, if you aren't running a blend or full synthetic in most cases I believe they all recommend closer to 32:1 or so.

Not to discredit you, but, IMO about the only way to synch carbs without the flow through meter is by touch. Actually have the filters off, and feeling with the same hand when the slides first move. This still isn't quite as perfect as the acutal meter, but I got mine REAL close by feel; I just don't think you could see those very first minimal movements. But just my $.02 Is this when you first warm it up, or all the time? Another thing to check, that mostly only applies when fuel is lower, one carb, can't remember now which one, does not get as good of flow from the T in the gas line. When I first bought mine, you could actually see the hoses were slanted at the T, biased towards one carb. If you're flowing a full fuel line, you wouldn't notice though until in theory you emptied the bowls or were low in the tank.

Deckheight, what do you recommend for polishing off the exhaust? That finish was just my rough in with the burrs; no sanding, polishing yet...

The 90 degree tool from CC is awesome; it's a spendy bugger, but I'll tell you, I worked the transfers over as far as timing, as fast as any other part of the porting. I got the specs recommended from my by Dan Wade (Patriot) back in the day a few years ago. As I recall he said he felt it helped with top end scavenging; As you said, you can't even "see" a difference, but it is there, even if a couple degrees of crank rotation. I know Snop knows Dan, I wonder if this sounds like familiar recommendations? Yes Snop, need to work the intake roof lip more for sure. As far as domes are concerned I'm actually not sure, I wanted to ask around. I'm running 20cc currently and I kick 175psi at 1900' elevation, which I know is way higher than most feel it should be. I would actually like to maintain close to that, probably around 185 at sea level, currently right over 190, but I'm not sure what size to run. I have some 19's but guessing those probably won't be small enough to maintain that PSI. Okay running a healthy mix of Trick 116 at that PSI...

Do you have any pictures of the transfers, exhaust etc.? Did you change the port timing or just smooth out the intake? I will definitely say that doing this right is not the economical way to do it. Quite some time ago I purchased the 90* tool from CC Specialty, which alone ran me about the same as what a good port job from any builder on the HQ would cost, excluding a drag port most likely. But, even if I only turn out 65-70HP instead of maybe mid 70's, I have the satisfaction of saying I did them entirely myself. God, I can't wait to get this thing on the dyno and see what it pulls now, then swap cylinders and see what I was able to do with it!

Yeah, would have to agree that YFZ +2 Arms would be WAY to wide once on your Banshee to really be useable. Stock YFZ arms and my ITP wheels make the front of my bike track as wide as my buddies stock Rhino, so +2 YFZ, yikes. My recommendation would be to take some measurements off an a-arm bike, weld mounts in that location and then run modified arms, if you want to do the YFZ conversion. My rationale for that is this; the "benefit" of the YFZ conversion is that you not only get wider suspension now, but you leave the bike unmolested so you can always upgrade to aftermarket arms down the road if you'd like. If you weld mounts for the YFZ arms, in their location, so they bolt up unmodified, you will only be able to run YFZ arms. Also, if the front j-arm mount is in the same place as an a-arm bike, you would still need to modify the YFZ a-arm where it mounts to the frame for the front mount, otherwise it would shift the arm back further and your caster would be basically zero.

The numbers I mentioned up above are the degrees of crankshaft rotation that each of the ports mentioned are open. All of those durations are greater than the stock port durations, which translates into longer intake period, i.e. more fuel/air, somewhat shorter power stroke before the exhaust begins to open. I read up quite a bit from the two stroke tuner's handbook by gordon jennings. It has quite a bit of information on the theory behind how a two stroke engine works. It doesn't really explain that much "how to" port, but it explains the concept that basically tells you "why" to port. Now, I had a set of port durations recommended to me, I didn't arrive at these numbers through calculation. With the information you can learn from Jennings though, it would be possible and it made sense as I was putting the number together with what I was reading. Just google the title and author above and you should be able to find a downloadable PDF out there. I downloaded it for free about two years ago, but not sure if it is available free still? Only have the first cylinder done so far. Hopefully I will finish the exhaust on the first and finish the second cylinder this week, that way I can potentially fire it up next week. I still need to mic the cylinder though to see if I can get away with a touch up hone at my house or if I am going to need to have it bored just slightly. The cylinders are in very good condition, so I believe I will get away with just a simple three stone honing. I need to figure out a way to mount the cylinder though so I can jig it for the hone on my drill press. The stones on my drill powered hone are floating and in theory can be run by a hand drill, but I usually prefer the press. What kind of durations did you do on your first port job? I'm running the mods in my sig and only ride the sand out here in Oregon, so the slightly higher exhaust numbers are to hint towards the top end. I can already tell that this is going to make the addiction worse though. I already forsee starting on my current cylinders once I pull them to throw these on. Then I'm going to want CPI's and higher exhaust figures. Geez!!!! :biggrin:

I'm not planning to enlarge my intakes any as far as the opening into the cylinder. But, I knew that I needed to work the roof of the intake a little more. I smoothed it out quite a bit, but it is not a constant slope from the roof down into the port... yet.

Alright, so I've recently gotten inspired to start my porting project. Not sure what kicked it in, but after two evenings that turned into early mornings, I've got one jug almost entirely done. I need a couple longer burrs to reach into the intermediate portion of the transfers and some sanding drums and flaps to finish off and polish up the exhaust. The specs are as follows: 188* Exhaust duration 127* Transfer duration 129* boost port duration Main transfers have been widened 2mm towards the exhaust Now, I don't at all claim to have turned out a jug that is near perfect or quite as smooth as the pro's do it. But, I do really think they should make good power and I think they are shaping up pretty alright. Let me know any thoughts or "enjoy" (?) the pics??? Intakes Side by Side Ported Intake Exhaust Side by Side Another exhaust One transfer after changing the port timing, one prior Notice it has been widened towards the exhaust also Exhaust has not been worked yet. Transfer and part of exhaust Can sort of see the difference between stock transfers and modified Anyway, sorry if I'll bore anyone with these... - Brian Transfers from base

Totally agree, with my SE shocks having high and low speed compression adjustment, I can really dial in my ride for the dunes at least. Ane believe me, our Oregon Dunes can get really rough with the moisture we accumulate! Peter, not sure if you were talking about poster's bike or mine, but mine is about to go big. Just picked up some YFZ450R shocks that should make a world of difference!

Wow, I would imagine this will help the original poster, but I know for one that it will help me a ton. I've been planning to build my own swinger for some time now. After the most recent trip, it's apparent that I really need it. Plus, I'm porting a set of cylinders for the bike now, so it will become very necessary soon! Thanks! For me at least!

Yes I do!!! Thanks for the plug David!

That's right, I do remember that now. Well, I remember from back in the day when I started that post on PS, that you could tell he obviously knew his stuff!!! I had forgotten that piece of the puzzle by now. I couldn't belive he would just come out with all those specs at the time!

Oh yeah, those specs were for a stock stroke, so... :shoothead:

Haha! Found it! This is a very old post... Surprisingly my login was still current, but found I have very little access to PS now! http://www.planetsand.com/forums/ubbthread...1451#Post421451

I have some porting specs that somehow I was able to talk a reputable member of Planet Sand out of back in the day. I'm getting ready to grind on a set of cylinders myself, even popped for the right angle head tool, $300+, so I need to get my money out of that. The specs I had were right around 188* exhaust duration, but I had transfer specs, boost port opening specs etc. I can't find the flippin' file that I saved on it right now, but I'm digging for it tonight. I'll see what I can find. It was for a medium aggressive "dune port" though, not full out drag. He actually even went as far as to mention areas within the transfers that I should address, just from a flow standpoint, timing aside. His screenname was Backcountry on PS if I remember right?

Currently have a set of orange arms and a set of blue arms (new balljoints lower) prepped for shipping. Also, still have a few sets of spacers in this initial run. ALSO, have a new twist on this conversion that has me excited! Hope to be able to post pics up within about a week or so!!!

I have the spacers available. I am the member Facetious referenced up above. I sell the spacers for $55 shipped to any lower 48 state, via Priority Mail, usually arrives within a few days.

Completely agree with all of this, especially the last line... :biggrin: But yes, those are very average, normal prices that you will find on core parts.

Alright, I have a few sets of spacers left in this run, two sets of a-arms (one blue, one orange). A-arms are $265 and $280 shipped to lower 48, including my spacer/sleeves. The blue arms had messed up ball joints when I received them, so they are getting brand new ball joints ($35 total) on the lowers, thus the slightly higher price. I also have a set of NOSS tie rods that I can package with a kit for an extra $35. Also, have one set of YFZ450 shocks at this time, might be getting rid of my SE shocks, but need to make arrangements for different shocks first. Thanks! - Brian

On a couple kits I have put together, the knuckleheads removing the a-arms destroyed the ball joints, boots/threads etc. That's always nice from the biz perspective to find out there is an added undisclosed cost when you buy core parts. I found factory replacements on eBay for $17 shipped here a while back. I know that'smore than the $5 setup, but if you're looking factory, that is another option.