2003LimitedBanshee

I have to agree here. With my bike, all of what samdust listed, plus timing advance, VF3's etc., I can just barely hang with my buddy on his 426 in the sand. He says it has just a bit more in it, but I've seen him ride it hard and ridden it myself and I would put it at a dead heat. Now, you factor that he does a fair amount of digging off the line, and if I can keep the front down (hard with the stock swinger on big launches), I can pull him by no more than 1/2-1 bike length. But, if pull the front at all and have to lift I cannot come back around him. I don't know about corn fields, but in the sand at least, I would bet on the Banshee. Riding one of my buddies YZ250, which is admittedly abused, but not sick, once I jetted it for him, I would say my Banshee was noticeably faster than his bike. Dirt, who knows, the sand sucks a lot of power.

You have to think about the degrees of advance in terms of time. If you are turning 3000 RPM with your bike (not very fast I might add), the crank is making 50 revolutions per second. Now if you break down the crank rotation into degrees and you think about firing the plug 4 degrees before TDC, you are talking fractions upon fractions of seconds. So the benefit is that you start the fuel/air mix burn a little earlier. You have to realize that when the plug fires the fuel/air mix doesn't immediately fully flash and burn to provide the power stroke. In addition, because two strokes have 2 less strokes they have much shorter power strokes, meaning far fewer degrees of crank rotation before, in the case of a two stroke, the exhaust port is unmasked by the piston, the earlier you fire the mix (to a point obviously) the better. Advancing the timing helps to build torque in this case because the point at which the burn exerts more energy on the top of the piston it has greater mechanical advantage. Now, if you retard the timing, it will fire the plug later giving it slightly less mechanical advantage, but because it doesn't resist the movement of the piston it should allow for more overrev ie. higher rpm ability and power. I say it doesn't resist the piston, because technically firing it before TDC does slightly start to expand the fuel/air mix while the piston is still moving up. Remember, we are talking fractions of one second, so it is not extremely drastic. Okay, hopefully in my rambling I have made some sense and not confused myself either. Good luck...

Ditto to T5's. I would agree with loco, in wondering if the T6's really out-pull the T5's, but popular opinion seems to point towards no for sure on ported bikes.

Dajogejr, I will definitely agree that from what I read around here I am in the minority with my experience with the TORS. I know that I didn't have any bad experiences, but it seems most have, so.... I'm good with my statement that it has worked for me, but also good with the fact that you say it hasn't for you. Like I said I think we can agree that it is designed to be a recirc system, but disagree as to whether or not it works as designed. Fair?

First, I must stand corrected on one item, the coolant system actually does all of it's recirculating through the bottom tube of the overflow tank. Banshee dave was right in saying that the upper is an overflow for the recirc tank. Now, Bansh-eman, the point is not whether or not you can run with 4-6oz less coolant, the point is that the bike will cool less efficiently if it cannot maintain a completely full system. The fact that the cooling system moves fluid into the recirc tank doesn't mean that it is overheating, that is what would cause you to lose fluid through the hose near the radiator neck/cap, that also dumps near the right side pipe. If you think about all relatively newer (early 80's-up) they all have recirculating cooling systems, and they all recommend you add fluid at the recirc tank, because the radiator itself should never be less than full unless you have let the recirc tank run dry. Furthermore, most only have one hose running to the tank that it both pushes and draws fluid to/from the recirc tank. Dajogejr, I respect your time and experience, and I guess I could reconcile that in my experience and also in theory, it has worked for me. I can't speak as to why it hasn't for you, but if you say it hasn't I have no way to say that is has. I think we can agree that in design this is more than simply an overflow tank; it may not function on some, for some unknown reason, but it should if all was working. I guess I've just had good luck. I never understood/understand why people bad mouth the TORS either, as mine worked fine, on two bikes with no flaws. I just simply removed mine from this bike to make rejetting easier.

Nope as in serves in place of head gasket ^^^^^^^

Nope, orings serve in place of the head gasket. Orings are used because they handle the increased compression, ie. cylinder pressures, better.

Chevrolet, how come you dropped your coolant system post? Anyway, you won't really see any HP improvement to speak of by simply increasing the bore. Chappy, until you uncork that bike with some aftermarket pipes, filter, etc. etc. etc. (and there are a lot of other etc's) you'll be throwing money away on a bore. Wiseco's are a good choice, but as I said there are many things you should do first. If you look at my sig, I'm am still on the stock top end, pistons and all (with great compression I might add), with the mods listed. When I tear my bike down to do the porting, I will be swapping to a set of Wiseco's at that point.

Has anyone actually looked at their radiator or taken the time to try and understand the basic concepts of a cooling system? I'm sorry to come off so harsh, but I remember this same debate some time ago, and I believe the same ignorant opinion won out. Anyway, if you had actually taken the time to look at the radiator you would realize that in part you sort of answered your own question. While it is true that there is a line that comes off the radiator neck near the cap, you should have noticed the line that comes off the other side of the radiator, directly from the top tank of the radiator. The line you saw and commented on from the radiator cap is the line that will spit on your pipes. And you would be right that there would be no way for the radiator to draw fluid back from the Recirc tank IF this was the line that it used to draw from the recirc tank. Luckily for me, it isn't. The fact that the radiator cap seals and creates a closed system is what creates the draw from the bottom tube of the Recirc tank back into the radiator. The TRUE overflow line from the radiator neck, near the cap, just serves in the case of an overpressurization in the system. Basically if the system gets too warm too fast, or just plain too HOT. Otherwise, as the system heats, coolant expands, it pushes the expanded fluid into the recirc tank from the bung on the right hand side (from seated on bike) of the tank into the top tube in the overflow. As it cools, coolant contracts, it is drawn from the bottom tube in the recirc back into the radiator. Not to sound like a complete ass, but that is how it works, either that or Yamaha just made all that extra work for a whole lot of smoke and mirrors.

Heck, anyone who doesn't still have their instructions could just go to the website and download them if they wanted to, but they'd still be reading incorrect information. I love my Toomeys, and think their design is amazing, BUT I will make this statement. In this case, it is a good thing that Toomey designs pipes and not Cooling Systems! Simply count the hoses, if you understand how a recirculating tank cooling system works, you will have your answer. If all you need is a place for coolant to spit, you only need ONE hose. In this system, properly functioning, coolant comes in through the top hose when the coolant expands, and is drawn back into the radiator via the bottom hose when the coolant contracts. People can argue all they want, but the simple fact is that by design this is a Recirculating System. You may have a better chance of convincing me that it doesn't function as shipped from Yamaha, but it is still a Recirc. system.

No offense intended, but how do you add "un-needed compression"? Adding un-needed octane as I've heard many do before, is of course, un-needed. But, until an extreme, where too much compression can actually cut performance, added compression is performance. You have to make other appropriate changes to compliment the added compression, ie. fuel octane, improved cooling, hotter spark in many cases. But added compression is a mod in of itself. Probably one of the few scenarios I can think of where added compression would be a waste, would be on an airboxed, stock pipe motor; otherwise, give me the compression. Now, if you would have said that you could take better advantage of the added compression with further mods, I'd be all for that statement, but to say that adding compression is nothing but a waste unless you have a "heavily modded" motor I would have to say is false.

Depending on what kind of riding you do, (what kind by the way?) you may very likely want to reconsider those FMF's. I know a decent amount of people swear by them, and they are better for a bit more bottom end, but you will find much more top end power with several other pipe choices. I would wager that about the only thing you will hear most anyone recommend FMF's for are a woods ported trail bike. Any type of sand, drag etc. and you have better choices out there. Albeit, you have pipes now, and they are far better than stock, but something to consider for down the road and something you should consider in the future mods you have planned.

What is your elevation for starters? The reason I ask is because with 20cc domes in my NOSS I kick just over 170 psi in each cylinder, on an otherwise stock jug/piston assembly at 1980' elevation. It kicks right near 190's at sea level. I know, seems high, but I've verified it several times with my compression gauge; SNAP-ON by the way in case anyone was thinking of throwing in the "buy a good gauge" comment. Bone cold, not even run before the test. As mentioned it doesn't typically make a huge difference.

But the point of a functioning recirculating tank is to ensure that the effective cooling system (ie. radiator) is full at all times. Any cooling system is most efficient if it is completely full. In addition, you will lose some coolant to evaporation under normal usage, therefore the recirc tank gives you a resevoir to hold extra coolant to replace this normal loss. Most people do not check many things, coolant as just one aspect, anywhere close to often enough, so a properly functioning recirc tank is just another insurance/convenience item.

It most certainly can serve as a recirculating tank, which is distinctly different than an overflow tank. The main problem why most people don't believe they are anything more than an overflow is because of the stock tube routing and the fact that most bikes typically will not recirc without a rerouting of the tubes. Think about it, why would Yamaha design the "overflow" with two tubes (one high on the bottle and the other at the very bottom) if it was simply an overflow. If it were just an overflow, it would only need one. I'm suprised at some that stated boldly it was NOT a recirc. as I respect their opinions. Just a more thorough check of the theory I guess.

Exactly my thoughts. You often have to take some additional beyond just squaring up the bosses. I take mine down to where the locking surface of the boss is just shy of where the threads that you tapped start. This will ensure that you get the most adjustability.

Comparing the SST vs Toomey I would go with Toomey. Since it sounds like you are anticipating the "disease", I would say to go with T5's. But it is true, if you really plan on going big down the road, you may find CPI/Shearer to be more along your lines. What type of riding do you plan on doing? Also, try a search, topic has been covered A LOT, and recently I'm sure.

No the choke tube is the actual tube that goes between the two carbs. It is a small piece of approx 3" long vacuum tube the sends the choke "signal" from the left carb (sitting on bike) to the right carb since it does not have a choke stat. Look at your carb with the choke "knob" on it. Now imagine how the choke runs through the carb, on the exact opposite side of the left hand carb you should see a small piece of vacuum tubing that goes to the right hand carb. If you are missing that, you've found your problem.

Thank You! I was hoping someone would point that out. The two cycle engine, still a mystery to some.

A word of advice as far as fuel and compression is concerned. I went with 20cc domes in my NOSS head also, I wanted/want higher compression, but I currently kick 175psi on my stock bore/top end/port (very well maintained albeit). So if you are on stock bore/port etc. I would expect higher numbers than the estimates on NOSS's website. I am at 2000' elevation (I think I saw in one of your posts you were similar), so at sea level I estimate I should be near 190-195. If you are running any extra timing, plate etc. (like myself) I would advise race fuel (100% Trick 114 in my case).

Well, I know it's not the question you addressed but first, I would guess you are a bit lean on the main. I would expect you to be around 300 or 310. You can see my jetting specs in my sig, and I am at 2000 ft elevation, so no big differences there. Now, I am running an open element filter (no airbox) so that accounts for some of the difference, but I still think you would be a bit bigger on the mains. As far as idling goes, I know it sounds dumb, but have you checked your choke tube? I can't believe how many times people will miss this. From their, I would try going in a bit on the air screw, say to 1.0 turn out or so. I went up to a 27.5 pilot at one point, but ended up back at a 25, so my guess would be some additonal tuning on the air screw.

Yep, have to agree. Don't expect to let it idle for a bit, and take it out and have it dead on first time through the gears. There is a big difference between "warm" when it is sitting there idling with no load on the engine. Take it a little easier through first and second and "cycle" the throttle a bit and you should feel/hear etc when it clears out.

I've been using Tri-Flow for years. It works great! It sticks around (unlike those that use WD40), but it doesn't create the tacky film the makes everything stick to it. I ride in the sand and never have a problem with sand building up.

Sounds like a jetting issue most likely. Are you experiencing a bog? As mentioned 19cc is a pretty small dome, unless you are at elevation, or the bike has been ported (doesn't sound like it). I went with 20cc domes but most will go slightly bigger. I noticed a huge increase in the bottom end pull of the bike when I upgraded to my NOSS head, so I would have to assume that something is off. As far as the reed install goes. You have to cut the manifold for the reeds to even be installed, and yes you would need to replace the manifolds if you went back to stock or Boyesen reeds; but you don't want to. The VF3's will far outperform the stock or Boyesen reeds, so there must be something in the setup. Keep in mind with that head, you may be sacrificing a small amount of top end with that much compression (probably won't notice seat of the pants, dyno maybe), but then again you aren't running a top end minded pipe. Switch to the Toomey's (T5 would be my recommendation) or the CPI's (probably my next pipes) and you might see some of the top end sacrifice.

That's almost as hard a question as "what pipes are the best" because everyone seems to have their own opinion. But, I would say that general consensus is around 150 psi and up you should start running a blend, with NO timing advance. I haven't messed with shaved heads that much, but at .035 off and timing advance (whether it's at +4 or +6, which you need to determine...) I can't see a way around a mix of race/premium. I've always opted for a bit more octane, as it beats the alternative. To give you an idea, I kick close to 190 psi and +4* at sea level, and I run 100% Trick 114. I would bet you'll be in the 160-170 range (shaved head guys correct me if I'm wrong), so if it were me I would probably run 60% race (3 gallons race and 2 premium because it's easy in 5 gallon jugs).