tfaith08

Thacker, I can see what you're getting at with all of this, but it seems biased. Your theories are great, but the application of some of your thoughts wouldn't be there. Finding logic to support the outcome that you hope to find doesn't hold up very well when doing REAL research. Trust me, I know. You should know as well since you have a degree in applied science. It's obvious that a steel unit would stand up to more abuse. However, it doesn't dissipate heat nearly as well as aluminum. If you apply any given amount of heat energy to steel and then apply the same amount to aluminum, the aluminum will get hotter, but it will also dissipate the heat throughout the material and shed the heat quicker. Since all of this is partially submerged in fluid, the aluminum will have an even greater chance to pull and shed more heat than steel. Further contributing to this, the aluminum will have a more even heat signature because, again, it dissipates heat much more. It's kind of like when you weld a 5' piece of steel and grab the side that you didn't weld on; you can grab it and it won't have much heat to it. If you try the same thing with aluminum, well... you'd best have gloves on. It's also like when you install an aftermarket head on a Banshee. The aftermarket piece will pull more heat from the engine and get it into the coolant, resulting in more heat being transferred to the radiator. If you check the radiator with a laser before and after, the radiator will be hotter with the aftermarket head, but the tops of the cylinders will be cooler. To make it more accurate, try this with 22cc domes on a stock bore and stroke engine so that you can't say that the increased heat at the radiator is a result of the increase in compression/heat generation. Back to the clutch. Standing up to extreme heat isn't so much the issue with the boss, basket, etc. Your theory would be correct if the aluminum was directly generating heat, but it isn't. The heat is generated by friction when the plates slip, when the friction material warps under acceleration, and when the teeth on the gears of proximal assemblies roll past one another. As such, aluminum is a superior choice when aiming to pull radiant and contact heat from the plates (which are what generate heat) in an effort to prevent clutch fade. As for you to experience wear to the extent that you have, you likely have another problem at hand that presents as clutch assembly wear/breakage. This was also stated on E2S in the thread that someone posted the link to. An exception doesn't warrant a rule of thumb; it's just an exception to the rule. I will agree that the increased rotational mass, which is largely influenced by how much material exists away from the axis of rotation and the distance from the axis, can be easily offset by machining the flywheel even lighter. This can, as you said, be calculated. Lastly, you claiming that your IQ is higher than everyone else around here is something that you'd do well to stop doing. You may very well be pretty sharp, but your logic here isn't a reflection of your claimed above average intelligence quotient. Furthermore, I have paperwork to show that I have an IQ of 161, so go ahead and stop before I put you in your place.

Wow, CT sucked way back then, too. Anyway, is there an update on this thread?

You're welcome. I'm always for information flow. After all, it is a forum. If you're after increasing flow and velocity out of the secondaries in that manner, I'd look into what Passion Racing has done with their cylinders. They've added a port under the secondaries and in front of the piston ports. I have no details outside of what very rough port map I can visualize. I don't know width, height, aim, curves, nothing. Then, I saw a KX500 cylinder with similar modifications and started thinking on it. At this point, I haven't come to a conclusion on which way they should be aimed nor have I determined contours. I have thoughts, but no test results. Again, that's just something I stumbled upon. I'd leave it alone if it was Passion's claim to fame, but I found it in other stock cylinders. That justifies me tampering with the idea. Also, keep in mind that Boyesen port aiming will have to be re-thought as these extra ports will affect the flow to the secondaries. I'm sure that extra cutouts in the pitons will be beneficial. I'd like to say again that Passion Racing has this down to a science, whereas I've just observed 2 pictures on the matter and thought about it days on end. Don't think that I'm out to take over the world with Passion's design. As for the kick, the design almost makes it a restriction than a kicker. I think that some planned epoxy work here will be the key, but that's another area that I haven't fooled with very much on Banshees. I do it regularly on 250Rs, but they have the casting to allow for such modifications in an easy manner. Also, since you have the extra aluminum added on, I'm sure that you can work with a little more leniency than others. Just to get the mind going, I've seen a guy cut the transfers off of his old Rotax cylinder, reshape them, have them welded back on, and clean the inside of the welds up. Combine that with a blank sleeve like some of the hot saw guys do and imagine the possibilities...

I've tried to get my hands on it a while back, but gave up because I didn't know it was that good. I'll check into it. I'm about to get into a KX85 this weekend. The guy wants it ported, so I'll be doing the math here if I get the time. I haven't been in a cylinder that small in a long time. Time to go get some more 1/8" tipped carbides.

Speaking of an air leak, I've got a YZ125 that a guy is bringing in tomorrow night that's been through 4 top ends since September. It's a stock bike with a one size larger jet than stock and he's running AV gas mixed 50/50 with non-ethanol 93 and ran 32/1 with super techni-plate.. The guy that he's been taking them to has given him every piston and they have all had scarring and very worn rings. The builder has also given him all the plugs and called it detonation every time, which isn't the problem; all of the insulators are solid white. So add that all up. Even though they're friends and he cuts him deals, he's still paying $300 for each rebuild. That's $1200 in rebuilds, plus the AV gas. But I ask everyone that has a 2-stroke what it's worth to them to take 3 hours and $40 to build a leak tester to make sure that they don't have an air leak. A top end? A top end and bottom end? More? What's shitty is that people tend to overlook what's recommended to them and then tell everyone that the forum guys are a bunch of idiots because that person asked a question and the forum guys couldn't come up with an answer. Not saying that's you, but still. It happens A LOT.

Bennett, chill out dude. OP didn't ask for recommendations, he asked a yes or no question. If he has some lying around or can get some for less than $50, it wouldn't be a bad deal if he just wanted to lower it. OP, yes, they'll fit. People swap the Blaster shocks out for Banshee shocks all the time, and you have a picture in the thread of another user doing the opposite.

A Banshee can still pull very well up top with a good woods/trail port. What big bore are you going with? If you chose the 21cc domes so that you can run pump gas, the largest bore I'd go with would be 370cc. 21cc domes on a 370 is roughly equivalent to running 20s on a 350. Some get away with pump gas, others don't. Timing would affect this as well. Of course, if you're going with a build for more bottom end, I would leave the timing stock or even retard it. What pipes are you going with? Also, the larger bore in relation to a set of domes meant for a stock bore will give you a slight shift to the right on your power curve. It would be very, very slight though, but it'll be there. If you're going with Jeff, I'm sure you could bother him for a few other thoughts on the build while you're at it. He knows what works well with his porting, I'm sure.

I've never had problems with Pro-x or Wiseco. I have no clue if Wiseco sells a 65.75, but I'd imagine they do.

Not to discredit you, but describe the process that led you to state that it didn't have an air leak. I wouldn't run it for another second until you were positive that it didn't have an air leak. A thorough test here can potentially save you a rebuild. Seems to me like you have an air leak... free revving, sporadic running, and not tuning are 3 tell-tale signs.

I'm at 145' ASL and I'm running 150psi with 21s and a Chariot head. Just figured I'd throw that in for reference. If you back off the timing, you should be fine with 93. I'm running the 21s with +4 timing in 90+ degree weather and I'm running great on 93. I'm sure you could do well with stock timing.

Props for going forward with it. You can read and research all you want (which is a necessity imo), but actually doing the work is where you start to find the questions that need to be asked the most. Nobody cares about port geometry before they get into their first cylinder. Keep it up. About boring then porting, I don't like it. If you have angled ports, the height changes and the width and position changes. I mean, it is slight, but it's there. All it takes is a sneeze or a slip of the hand and you're running a carbide across the cylinder, so I'd leave the hone for last. Bore, port, hone. That's what I always do. I'm working on some Banshee cylinders now and the transfers are nerve wracking. I wish they were more like 250R transfers. As for the tunnels, if you want to remove anything, I'd remove material from the outside/front if you're just dying to remove some. I did this to the last set of Banshee jugs and it added a bit more bottom end, but it wasn't drastic. It keeps the charge to the back of the cylinder. Also, I've found that the Boyesen port angle affects power delivery. I've found that those that are angled more downward produce more bottom end response, while those that are angled more toward the mains give a bit more top end pull. Try to think of where the charge flows when it comes in, how long it dwells before it re-directs, and where the majority of the flow has ventured to when the transfers start to pull AFM. Make sure you don't remove the kicker at the main transfers. I've modified some in the past and only did it slightly. I've never really liked the race logic templates, but to each his own. Once I get my 250R port map how I like it, I'm going to map it and put it on a magnet strip to make future jobs easier. I think the next one will be alright, but I'm going to keep porting them until I port one that hauls some major ass and then make that the template. My last one was alright, but this one will be better, I think. If you're thinking of polishing a short side radius to help the AFM adhere to the curve and pull in that direction, it does work, but fuel pools in the polished spots. Not a very good idea IMO. I have a good friend who tried this on a 450R head and then went back and roughened it up a bit. He said he made 2 more HP on the dyno, which he has regular access to. I'll see if he'll send pics. If you look at the porting thread that I posted a while back, there were a few people that chimed in with some good info. Notably, camatv said that getting the air into the cylinder in an orderly fashion was a definite goal (not verbatim). The biggest recommendation that I have is the boost port. The 90 degree edges all around don't help flow too much. If you still have the room for it, I'd round those edges off some. If you only have 1cm or so left, I'd leave it like that. Otherwise, the flow just kind of blobs in the cylinder, rather than flowing in a path. Think venturi nozzle and then adapt a less extreme version of that. It worked pretty well on my wife's Blaster. I didn't recall whether you did it, but I think you mentioned rounding the ports off where they enter the cylinder. I wouldn't recommend that, but that's jsut my thinking; I have no experience/data to back that recommendation up. registered user did have a good point when he said to open the rear of the secondary up at the cylinder. The kick can be improved upon by flattening the rear wall out SOME. Be cognizant of where the rings fall when doing this. I've pondered extending the top of the secondaries to allow the mixture that extra room and to avoid a dead spot. Again, I haven't worked much with Banshee cylinders and haven't applied this yet. However, I have tried it with 250R cylinders and they have done alright with it. It seems to widen the powerband just a bit. I did find that (again, with the 250Rs) the effectiveness of widening the top of the secondaries was largely dependent on the continued shape of the tunnel. Just something to think about. All in all, good job. The workmanship is damn good for a first time job without the right tools.

Also, that's the way to use vernier calipers for anyone that was wondering. Take a close look at the exhaust por tin the 3rd picture. It looks like a widened and reduced radius port there, just with a square chamfer. Also, check out the front left main transfer on the right cylinder. Looks like he did a good job on the sleeve there as well.

You're still moving more air with the snorkel out. Check jetting and get rid of TORS. If you rebuilt the top end, did you do a leak down test? If not, I'd do that before you cranked it again.

Square ports will always flow more lol Wouldn't be a bad setup for getting someone used to porting. It would also be a good idea to get them to see exactly how thick the walls are so that you know how far you can take the port walls out. I might get them so that I can throw them on an engine for a guy that really pisses me off.

Preference, maybe? OP, yes they will work. Banshee shocks fit on a Blaster and the same holds true the other way around. Don't jump it too hard because you can very easily max your ball joints out.

I think the question is: Do you have the tools to do it with? For example, to rebuild a Blaster top end and replace seals costs right at $200 with shipping. To buy the tools and rebuild it, it'll jump up to $600 ish. I'm always for a DIY job. However, you'd best do your research before doing anything (like calling RDZ for anything). If you're thinking of saving money on porting by doing it yourself, send it out. I do my own work, but I have almost a grand in tools for porting alone. It definitely isn't a money saving effort until you get to cylinder number 4-5, and even then, you're likely going to be short on power. The crank should come from one the site sponsors. Porting should, too. If it needs a bore, get the pistons first and then take the cylinders AND pistons to a shop to have them done before porting. Tell them that the guy doing the porting will chamfer the edges and then pay him the extra bit to do so. If you want to save all the headache and never wonder whether you missed something, just send it off, especially if you're not sure on building a stroker. A bad measurement on deck height, air leaks, etc. can wreak havoc. On the other hand, if you decide to go ahead with the build, just let us know and the information will be forthcoming.

Do those have rebound and compression adjustment?

Bump.

I know this thread hasn't been touched in a while, but I used to work for the Post Office I wanted to let you guys (chere) know that any tampering with anything that is endorsed by USPS (by endorsed, I mean touched by and/or process by any postal serviceman for official purposes) is a federal offense. If you send a money order through USPS and there is any infraction by any unauthorized individual, THEY ARE SUBJECT TO FELONY CHARGES. However, just because you send a money order to a seller through the mail doesn't mean they're obligated to give anything to the Postal Service for you because their only job is delivering mail, not getting people to mail stuff. Unless it's more than $5000, it's an issue of small claims court once the package has been signed for. The single best way to do it is to write a letter stating your intent as the buyer and their intent as the seller, and then write a series of numbers and letters at the top. At the bottom, write "If all stated agreements aren't mutually understood and aforementioned goods are not mailed in exchange for money order within 2 business days, return this letter and money order to sender. The money order is not a gift." Take a picture/get a copy of the letter and mail it as a certified copy at the same time as your money order is done. Request that the money order is package 1 of 2 and that the letter is 2 of 2. On the shipping declaration, write the same string of numbers and letters that you wrote at the top letter on the shipping declaration in the description box. Also write that string of letters and numbers on the envelopes. In small claims court, a letter will show the intent of the money order. The string of letters and numbers will link the letter and money order together, as will the box 1/2 and box 2/2, AND you'll have the receipt from the Post Office. The "If all stated agreements..." will show the intended purchase and purpose for the money order in your writing. Furthermore, the seller's signature will be recorded upon receipt of the letter. Certified mail is very, very much a solid piece of evidence in court at any level. Dates, written intent, receipts, pictures, and money orders will ensure that you get what you need. I wouldn't do this for every single little bolt and bracket that you buy, but if I ever buy anything for more than $500, I'm doing it. 10 minutes of work and $15 will get you exactly what you need to protect your wallet.

Also interested in the tires and rims. Got any pics of them?

Very interested in the shocks. Do you have pics of them?

I am very interested. Do you have a close-up picture of the shock?

What other mods do you have?

The YFZ shocks max the ball joints out while they're extended AND OFF THE GROUND DURING INSTALLATION. Once the bike is lowered to the floor, it will compress. Once you start riding, your weight will compress the shocks even more. Furthermore, I've never witnessed a ball joint go out that didn't show signs of wear, and I've been riding 4-wheelers since I was 4 and have been working on them since I was 15. I've never even heard of a ball joint going out without notice. Get the tires off the ground and pull the tops of the tires to the left and right. If they flex at the ball joint, they're going bad. The 250R that we have is running 450R shocks (can you believe that they max the ball joints out? CRAZY!) going on 6 years now and it just sowed signs of wear on the ball joints a month ago.

I'm right at 200lbs and I ride hard enough to max my front suspension out on a very regular basis. We just found a place to ride that has about 800 acres of sand, but we had to ride through a bit of mud to get there. After about 10 minutes, the dried mud was completely gone from the bottom front of the frame. It looked like it'd been wiped off from bottoming it out in the sand. It also stays above 90 degrees down here, so that has me leaning towards the resis.