canyncarvr

Yes. I understand the geometry aspects of less positive wheel offsets (wider stance) as it pertains to suspension input, toe-change, tire scrub, bearing load, and all. But I don't understand that as an answer to a wheel choice question, at least not my question. The point is not to go wider, particularly, it is to choose the better wheel for the application (sand): A 3x2 (more narrow) or a 2x3 (more wide). Maybe there are Banshee dune riders that have run both and have a preference?

I have always had 2+3 front wheels for sand use. Looking into getting new wheels 'cuz my old ones just won't hold air any longer..been whacked one too many times. I've heard that while a wider track in the sand (the 2+3) used to be popular, the preferred choice has pretty much changed to a 3+2 wheel (narrower stance). IS there a general consensus on front wheel backspace choice? A narrower front stance doesn't make a lot of sense to me..but as long as I'm buying wheels, maybe I should change. Thanks!

Notwithstanding the questionable tool..where did the idea come from to do a compression test on a cold engine?

For a basket to cause slipping problems it would have to be hammered pretty bad..hanging up the friction plates from returning to a compressed pack. Roll it backwards, hit the brakes..that would knock them loose. Until you used the clutch next time. What transmission oil do you use? Nothing 'SJ', right? And/or..nothing noted as 'energy conserving'? When you replaced the plates..you soaked them in the correct oil before install?

You don't have a starting problem now? It was resolved...right? '..and still nothing.' That means the jet change didn't effect the sputtering problem, or you're BACK to literally nothing. It won't start. Did you have the flywheel off?

I found a pic of a Banshee case...put 'goo' on it everywhere I see it should go from the pic point of view. Seeing as it's RED..maybe it should be loctite's anaerobic sealant.. Obviously someone that's done a couple dozen of these is the person you should listen to! It occurred to me that part of your question may come from wondering if it just goes on the 'outside' perimeter of the case. No. The crankcase (the flange all the way around the crank MUST be sealed). Uh oh...I missed a spot..around the bolt in the lower left corner of the pic...........

I've not had a Banshee apart...(or any of my R5s/RDs either). On motorcycles, it goes on every surface of the case that mates with a corresponding surface on the other case. It should be easy to see where the two halves of the case come together. That's where it goes.

Re: ' it has never run quite right..' That was with those nipples open? IF so, no wonder. I looked up the PWK28 on Sudco. The angle of the diagram doesn't show that nipple..and doesn't call out a PN for it. So, no help there. Considering where it is (downstream), that it sucks air, it being an injector hookup makes sense. Look inside the throat and I'll bet you will find a hole in the carb directly under the brass connector. ..like the Banshee's predecessor..the R5/RDs both having an oil tank and pump. They had Mikunis with an oil port in exactly the same spot (not physically, but effectively). That port serves no purpose in a pre-mixed Banshee (not including those with RZ motors in 'em..which probably don't have the oil pump on 'em anymore anyway), but certainly must be blocked off to prevent FOD..and a considerable too-lean problem. IF this machine was run for any length of time with those ports open, chances are as close to zero as they can get that there is no resultant damage. As far as this particular problem (no start),this 'compression, spark and fuel' is correct. Certainly there are variations within each that matter (like the TIMING of that spark for example), but your problem is one of the three. If you will be running your machine for '..2-3 minutes' while it sits, I hope you at least have a fan in front of it. Having NO idea what the current jetting setup is....with non-native carbs...it's a pretty much a crap shoot. Make sure the plugs aren't wet from trying to start it. If they are new..dry them with compressed air. With the petcock 'on' TIP the machine to BOTH sides until fuel flows out the overflow hose(s) of the carbs. If the machine is cold, kick it a few times with the chokeS ON (you have two..with no choke interconnect like the OEM Mikunis) AND key off (or kill 'on' if you don't have a switch), then kick it with key-on and/or kill off. The 'tipping' idea is a years old trick. For a number of reasons the floats may not be doing their job (contaminated float needle/seat for one, so they're 'stuck'). You KNOW there is fuel in the carb bowls when you see fuel coming out the overflows. Good luck.

Re: 'Can anyone technically explain to me as to why this is?' This is quite an old post..but a straightforward question that for whatever reason wasn't answered. The comment was made, '..not like four strokes...' Yep. Pretty much backwards timing-wise. The reason a two-stroke 'likes' retarded timing for upper-band RPM operation is due to the expansion chamber effect. A pipe on a 2-stroke performs two essential functions to 2-stroke performance. A 2-stroke pipe is composed of two cones, the first divergent, the next convergent. The pipe 'pulls' the incoming charge through the motor. That's the scavenging part. That's what the divergent cone accomplishes. The convergent cone acts..as you could guess...in an opposite fashion. It PUSHES the charge back into the cylinder before the piston closes the exhaust port. That's the supercharging effect. The design of a particular expansion chamber..the size and length of the headpipe, the diameter and length of the cones (the bell part of an expansion chamber) all fit together to make a 2-stroke perform as is desired and WHERE (RPM-wise) it's desired. The expansion chamber tunes the pressure waves coming from the cyclic nature of the 2-stroke engine operation (opening/closing of the ports). Retarding the timing on a 2-stroke motor transfers heat to the pipe..and it's that heat that tends to improve the scavenging/supercharging effect in the upper-RPM ranges. Thats's why you see ignition timing being quite severely retarded as a general rule in most 2-stroke ignition controls. And that is why 'this is'. Cheers!

re: 'they are supposed to be exactly the same.. ' And...when they are not? Thanks for the humor! :laugh: From this we learn that this Banshee does NOT have a seized piston. Just look at the piston on the right in your pics. IT'S not seized, they are supposed to be exactly the same, so by the above fine example of erudition, we KNOW the other one is not seized either! That's stoopid, isn't it. And it makes as much sense as 'Jet them both the same all the time because they are both the same all the time.' Think outside the tiny little box. Because 'I always..' 'I never...' 'I haven't....' or 'I won't...' is no reason to NOT consider the very real possibility that there may exist fact outside of what you know. ..and the Banshee doesn't even have a rotary valve! Imagine! Lectrons are obviously junk, it being said, 'I have never used a tapered bore carb...' makes that pretty obvious. FWIW (nada), my carbs are taper-bored..and they even have the same jets in 'em, right and left! :shrug:

There was a whitepaper published by McCullough some time back regarding oil/fuel ratios. They tested fuels mixed 'oil-rich' to the point of plug failure and found that the more oil they used, the more power they got. That was due to the better sealing properties (piston-cylinder) of the higher volumes of oil used. But...balance in all things will likely be a wise choice. Running 16:1 oil/fuel mix is unrealistic for a number of reasons. The higher oil recommendations from manufacturers is generally considered to be a safety valve for them. There are not likely to be oil related failures when you use SO much of it. But, like most everything else made there is room for improvement...especially when the focus of use is narrowed to include a particular type of riding in a particular environment. A 'good' premix oil runs probably around...what...$40 a gallon? There's a good reason to run less of it!

re: '..possibility of the Boost bottle seals being to blame.' Anything leaking (including the balance tube and/or bottle hardware) can lead to a seizure. Yes, the type, angle, of the petcock, and routing of hoses matters. Generally speaking, the petcock being on the LH side, the LH carb hose route is shorter than the RH carb hose route. That gives you more fuel 'storage' in the RH setup. You can turn the fuel off and see which cylinder runs out first. (Not a recommendation btw..) Obviously a completely different carb setup would be..well..completely different. It is not uncommon to have different jetting requirements for the two cylinders even with everything else (boots/reeds/bottles etc) OK. Good luck!

Make sure the crossover tube (cold enrichment) is in good shape AND properly fit. One that is not will destroy the RH piston. **edit** That comment intended for VM26ers, no application to Keihin. I glossed over the PJ part. If the petcock is restricting fuel flow the first piston most likely to feel it is the left piston, not the right.

All other things being OK (float condition, float level, no mechanical obstruction etc.) a leaking float needle valve/seat can be resolved by burnishing the seat. A machine that has sat with untreated fuel in it for too long is an excellent candidate. Cut a thin strip of wet-n-dry sandpaper (the black stuff ) to cover the end of a cotton swab. Start with 280. Cut the strip long enough to hold with your fingers...say 3" or so. Wet with alcohol, insert into the carb (not necessary to remove the seat) and clean the seat with a twisting motion. Follow with a strip of 400. Remove any residue as needed. BraKleen works well. If the needle itself shows any damage at the tip..dents, impression...or is hardened by age (in the case of a viton type tip), replace it.

OK. I did. The funny part of that is I understand: 1. The meaning of the phrase, AND 2. How it does not apply in this case. You presented an argument (more complaint, really) that was wrong, unfounded, incorrect, in error, and misguided. I corrected the error with fact. That you do not understand is a perfect example of something not understood to be therefore considered by the one lacking understanding to be bogus. You are welcome to take issue with the facts of the matter. ....makes your point of view no less wrong. You're welcome to it, though!

I'll take it in little steps for you. Peddle fast, now!! Pretty much. That's the point of having diverging/converging bells on a 2-stroke pipe (expansion chamber). There is a return pressure wave that results from those bells that, depending on size, shape, and length pushes air/fuel mixture back into the chamber...that mixture that is 'new' and IN the pipe due to the scavenging effect of that same pressure wave moving in the opposite direction a bit earlier in time. That's where the wet-line jetting method comes from. But, you have probably read all about that in some aftermarket websites who make banshee heads. Pretty much. 'High compression' on a supercharged engine is not a good thing. Which, of course, is why SC engines rarely run over 3:1 static compression. Now...that would be 'low compression'! Maybe there's a place somewhere inbetween that works better? Is such a possibility even remotely possible? Hhhmmm....so an alcohol fueled engine does run 'hi compression'? Whether injected, carbureted or stuffed (roots, centrifigal or turbo'd) probably doesn't matter? If they bothered to explain it to..well, some (if the shoe fits and all that...) those 'some' probably wouldn't understand it. Besides that, why would any 'aftermarket website who makes banshee heads' even consider explaining what they do to make their 'stuff' work? Billet bling? I'm sorry...you are of the understanding a squish is something shiny you bolt onto your muffler for jazz effect? ...summore. I would be interested in a lesson on squish from you if you have the time: What it doesn't do, why it's not important, and why everyone shouldn't care about it. As a blanket statement, that is true. Higher compression is not always a good thing. OK...enough fun with all that....... The math (I won't bother you with the details) tells me the banshees with a RB Designs modified head change to approximately 6.9:1 over the 6.5:1 advertised in a stock banshee engine. I wouldn't call that 'high compression'. You would be hard-pressed to find anyone that would call that minimal change much if any significance, let alone 'high compression'. A basic understanding of internal combustion engines (2 or 4-stroke), the actual 'combusting' part of them, will include if not an understanding of all the whys and wherefores of the importance of squish (angles, depth, shape etc) at least the glimmer of a thought that it means something. A lot, actually. The magic is in the squish!' Wow! Now wouldn't that be an ignorant thing to say!! I've never heard that myself..I would certainly benefit from perusing more 'aftermarket websites'. Hey!! I found one!!! That, btw from: HERE! Imagine that! Doesn't everyone know what their meter-per-second squish velocity is? Of course they do!! That's why you don't read much about it on all the aftermarket websites! Why belabor the obvious!!?? ..for the very last time..honest! Well, of course there is always the possibility that Eric Gorr is a baboon and a maroon, too!! Obviously he's the master of billet bling AND the King of Slowdown! OK. Enough fun...really! I do NOT know all about squish, MSV and how to change the former to increase OR decrease the latter. I know what works, though. But, heck....I've only ridden, rebuilt and modified 2-strokes for hundreds of thousands of miles and for over 35 years. Please do note the signature? 'Consider the source!' Well..and that latin stuff the meaning of which likely escaped...some. Cheers!

The last holed piston (RH side) I took out of a Yamaha twin 2-stroke was caused by a leaking crossconnect (enrichening..call it choke) tube. That shouldn't be an issue with a manifold. The gray color you refer comes from the aluminum that used to be part of your piston. While there is a difference between pre-ignition and detonation..the result can be the same. Obviously you can be 'too lean' and have your jetting perfect...the lean part coming from something other than air through the carb. Question: Is a burned hole in a piston due to a point source of heat? Detonation involves huge pressures resulting from mixture 'blowing up' instead of 'burning'. Yep..that can eat engine parts, too. Where is the hole? Top of the crown? Directly under the spark plug?

No 'professing' intended..and I don't play one on TV, neither! RB Designs (the one I referred to..Google comes up with numerous others of the same name) is in Portland, OR. He can be reached through RB-Designs.com. Disclaimer: I am not affiliated with RB-Designs in any way. I have used his services to improve the performance of my dirtbike, friends dirtbikes and the two banshees currently in the garage. I have his modified carbs on both Banshees too..that's another work of art that works! Saying I've had machine work (port jobs, head modification) done that was far less than acceptable, let alone 'good' is NOT any reference to any other's work I've seen referenced on this site, BTW. Not at all..in no way. Mr. Black (the 'B' in 'RB') is a super nice guy for starters..and his work is excellent because it works..and it's pretty, to boot!! This likely fits better in the product reviews forum....

It's not just a matter of head volume!! Having 150psi (pick some number) doesn't tell you a whole lot! Increasing combustion pressures by 'cutting' the head is often referred to as a 'good thing' when it comes to Banshee performance. Certainly there is more to it than whacking some metal off the Banshee head. I've had port work and machine work done on heads that ended up in far less than satisfactory performance gains. Some work has even resulted in performance losses! My Banshee would not hold 6th gear WOT in the sand unless I wound it pretty tight in 5th. Certainly if there was a headwind..forget 6th altogether. Another Banshee (same mods, not as new) was the same. I bolted a modified Banshee head from RB Designs onto the second Banshee a few weeks back. 'All of a sudden', I couldn't keep up! We were riding completely different territory so I thought my machine's performance was a matter of MY sense of the different terrain. Next trip out, MY Banshee had an RB head on it, too. Well well.... The two machines ran fairly equally...'all of a sudden'. I had far better throttle response and pull in lower throttle ranges..AND 6th gear pulled great not only with a short shift from 5th but from about 25mph! Headwind? No matter. Combustion pressure (kick speed) only changed about 12psi. Obviously the changes made in squish angle and piston clearance mattered a whole lot, too. What a treat to ride!! Beautiful work...done quickly, too!! Real quick. Impressive stuff.

re: screwdrivers Another vote for 'Please don't!'. Flywheels of the magneto variety don't like getting jarred, dropped or dinged. Well, neither does a flywheel of a NON-magneto variety. A sharp impact (maybe when the thing p-i-n-g-s off onto the floor) can cause a loss of magnetism. You generally fix that problem by buying a new flywheel. Expen$ive!! Get a puller made for the machine...cost about $10. Note the left hand thread part of using it!! 4

re: 'nice tan' Sorry, but...not exactly. Color is not the issue. Back up a bit. re: 'Why do it?' Because it is one of the methods useful to a rider to determine what his machine is doing jet-wise. WOT plug chops are probably the most common, but the test can be done at any throttle position. It's important that it be A throttle position with no movement of the throttle during the test because any movement means a different carb circuit will come more (or less) into use. The WOT part is easy because there isn't generally a whole lot of question WHERE that throttle position is. Maybe you've seen masking tape on throttle grip flanges with pen marks on it? That's how you determine where you're at in the throttle range for something other than WOT plug chops. Carb circuits do overlap a good bit, so the results of such testing will likely be less than simple to figure out. Yes, you pull the clutch (unload the engine from the trans..just a hint of decel braking will change what the plug looks like), hit the kill switch, and stop. Also 'chop' the throttle (drop the carb slides). The color of the plug insulator tells you things about fuel additives and heat, but not mixture. What you're looking for is the width (thickness?) of the ring at the base of the insulator. A ring one mm thick is generally considered to be 'right on'. Of course, that means your margin of error is close to zip. Premium performance? Yep. Maybe burning things up? Yep. If your ring is over 2mm, consider a jetting change (in the circuit you tested, natch). How long to run it? It doesn't take long for the ring to show. If you're at all thinking you are lean you're better richening the circuit your going to test and work down from too-rich. That's much safer than trying to work up from too-lean. You may only get one chance at the test if you approach thing from the latter. Less than 30 seconds will leave a mark..considerably less than that, actually. The longer you run it the darker (more defined) the ring will get. In real short tests, the ring may not go completely around the insulator. Modified or not, your machine will work better AND be more fun to ride if it's jetted correctly. Running what someone else runs in THEIR bike is not helpful to you. Machines vary and the same machine on the same day (atmospheric conditions make a difference) but with different riders will NOT run the same way and may well require different jetting if you want to make it as close as you can get it. Different plug types won't have much if any effect on this. If you like to run a High$ palladium fine wire, you don't have to burn $18 for a couple of plugs to do a chop test. Use a couple of less expensive -ES plugs. You will get the same information.

The question was: ' i was wondering how i could re wire the tors so it just bypasses the switch.' The answer is no. The switches (whether you are talking about the switches in the carb caps, or the switch in the throttle housing) sometimes have to be 'on' to work, sometimes have to be 'off' to work. The status of one has to match (that doesn't mean the same, btw) the status of the other. As stated, unplug the TORS control unit and the throttle housing switch (both have harness connectors) and the TORS will no longer be effective. Easier to see what's going on with the fuel tank off....

A couple of things missed from the beginning.....and that's what got you here. It's 'ported'? What does that mean? Nothing. There are so many different types of porting AND folks that do it, saying it is 'ported' means nada. Who am I? Nobody that you know...so do some research on what viable tuners/builders say (Oh...of course it's a given that EVERYbody is a 'good' builder, 'eh? That's funny!). I don't know that ALBA is well thought of on this board or not...but chances are they know more about Banshees than your average backyard tuner. From their website: Good porting can give you the greatest power increase of any modification to your Banshee, while bad porting, well, stinks. And (regarding combustion chamber pressure)... We recommend anywhere from 150-160 lbs. for a stock motor, and from 140-145 lbs for a ported motor. So...what you're running is (was) basically a grenade-job! You BUILT the thing to blow up!! 150lbs STATIC!!! (do you know what that means? It's different from 'dynamic'..and a 2-stroke engine's internal pressures are VERY dynamic!) chamber pressure, 4

Fact: The Banshee Jetting guide mentioned recommends putting the orange wire on the + side of the coil...says that it's usually wired backwards from the factory. My coil has a big '+' stamped on the terminal that is toward the rear of the machine. My Banshee came with the the black wire connected to that terminal I put an ignition tester (from Mac Tools) on today. The indicated voltage close to DOUBLES when the coil is wired with the orange wire to the front or negative side of the coil from the orange wire being wired to the positive side (rear) of the coil.

Kind of a btw...but, re: '..velocity goes up pressure goes down..' And it's air pressure that makes a carb work. Contrary to commonly held belief, carbs don't suck fuel out of the bowl. Fuel is pushed out of the bowl (into the incoming air stream) when atmospheric pressure is greater than the pressure inside the carb throat. That's what a venturi does..it creates a low(er) pressure than atmospheric, causing fuel to flow from the supply through the various orifices (pilot, needle jet/main jet) of the carb. That's part of why bigger isn't necessarily better, carb-wise.