blowit

Obviously the cylinders have had big bore barrels put in though. Is it ported? Might be ported up for a stroker

Yep, with about factory port height, the big bore is what is getting you. On a smaller bore, you would need about 17cc to see that. However, this is a great example of why NOT to put all your cards on pumping compression. The ratios indicate you are borderline race fuel.

Just put the keg in the back of the truck. We are all loaded up.... I suppose I should bring a lawn chair.

I am going to take it with the number of responses that not many people spray? Just checking.

Your compression likely did not go up. Your previous reading was not accurate. When you take the head off, measure the exhaust port height and the dome size and I can tell you about where you might be. I would not be sweating 210 at all.... As long as you are on race fuel. Brandon Mull Engineering

The plug gap change is not going to fix your starting issues! Your original question was "high rpm sputtering".

Did you ever drop the plug gap?

Green/red = stator ignition coil. Green/red striped = pulse coil. Both need checked.

First verify that the voltage regulator is plugged in. Small silver box mounted next to CDI. If plugged in, unplug lights, set multimeter on AC volts and connect to tail light wire and ground. Run bike up and see if voltage exceeds 15V. If so, voltage regulator is faulty. Do NOT plug headlights back in until you run this test again and confirm voltage stops climbing around 14.5-15VAC. Brandon Mull Engineering

I can't tell you how many new CDIs did NOT fix the problem but when the problem cannot be found, the CDI gets replaced. This is why I recommend borrowing first. i did that a month ago on a very difficult electrical issue even though I knew the CDI was very likely fine. Have to rule it out to focus on other things without tail chasing. No, pulling on wires or whatever will NOT hurt a CDI. Unless you can visibly see the plug move on the CDI, they are potted and not subject to that type of damage.

At least from here it sounds like you have done what you can to prove the CDI. Get one or borrow one. I do NOT recommend hard mounting them like OEM though. I like to at least put a rubber washer under them. Vibration and electronics don't work well. And Japan loves lead free solder which cracks out. You will not see NASA doing that.

If it actually fires up for a couple seconds, not just pop,pop, that points right to a fuel delivery issue. Please make sure slides are in the correct sides. If the left is in the right carb, it will be backwards. Also, you MUST have compressed air to clean the carbs. Take EVERYTHING out. air screw, jets, etc. Work on the air jets at filter side on the carbs. There is something blocked or not right, that is all it can be. Chock tube on? You sure those bowls are filling? You need to chase every passage carefully. Rare to have that much problem.

Did you test the pulse coil?

The only way to really know is with an oscilloscope. Scope the stator input right to the CDI, then the pulse coil to the CDI, then the Orange wire on the output. Remember, if the pulse generator gap is too high, the trigger trip voltage will not meet threshold for the CDI and it will not fire. typically if the gap is in spec and the coil resistance of the PG is in spec, it should be fine.

Voltage regulator will have nothing to do with your issues. The Lighting system and ignition system are discrete. from everything you are explaining, I am starting to wonder more about electrical issues here. When you spray carb cleaner, does it consistently start right up, then die? This almost sounds like a CDI failure.

^^^ Notes as I understand them. * Bike was running fine and just quit. Nearly eliminates jetting, bad fuel, elevation, etc * Bike seems to run fine when aided with carb cleaner. * Now says reeds have failed. Not sure if one peddle or what. That should cause an issue with running for sure. In many cases, the bike will eject the reed peddle without damage. I have seen cranks hurt from them but not common. If reeds are not in place or functioning right, the 360* of open intake duration means intake charge will end up ejecting back through the carb rather than stay in the engine. If the bike "just shut off", that points to something either catastrophic or acute, not something like "compression is getting low". I have had people tell me jets are clean before because they blew air through them. If you did not pull the pilots, physically look up their ass, poke a stick in their ass, and reinstall them, they are not clean. You say it "acted like it was running out of fuel". They typically will stutter, and lose one side first, not just drop dead. What did it do? If it dropped like a light switch, that tells something. What you have described can certainly point at electrical too with 20min of riding, then just dies. CDI, stator, etc. If that has been done and you KNOW the bowls are filling up, you have something else going on. A good time to verify that you have spark because some cleaners will go in and just detonate (no spark required). However, you ID'd a bad reed. That seems suspect first.

Test blk/wht right at the plug that you will have to unplug to test the stator at the CDI. Simply establish ground on black, then take one lead over to blk/wht. If you have continuity, the blk/wht is grounding at the CDI and the CDI will not fire. IIRC, the TORS, kill switch, and key switch are all using the same blk/wht lead.

The book is absolutely written WRONG! Secondary should test from cap to cap or plug wire to plug wire. No, I highly doubt you have any issues with the coil. Also, if the bike was working fine and you messed with a couple wires and now it does not, it likely is NOT the CDI either. On the CDI, there is a black and a black/white. Test that the black is at ground potential and the black/white is not. When bk/wht is grounded, the CDI will not fire. Again, do as i said in the previous post. There are tons of guys here that replace parts and more parts until something works. In many cases, the part was never even bad but for instance, if the plug for the stator needs work and you replace the stator, whala, the stator must have been bad. Another thing to watch for is DMMs (digital multi meters) that do not induce really any load on a wire. Older analog testers will move some current in the wire during test which helps catch issues like a wire hanging by a thread. I have my money on something simple here.

Can't even tell you how many carbs I have fixed by just cleaning the pilots. People "clean carbs" but never even take jets out and verify they are open. The pilot holes are so small that even compressed air rarely clears them. They need a roto rooter job. You might be able to get the bike fired by just pinning the throttle WFO which will start to pull fuel off the mains. If it fires, you know your pilots are fucked. Brandon Mull Engineering

Drop your plug gap from the factory .028 to .020 and report back. Brandon Mull Engineering

heat dissipation is a function of 3 main things, the thermal conductivity of the source material (in this case, Aluminum), the delta T or differential temperature between the material (very close to coolant temp) and the air around it, and the surface area. In short, we ran some numbers for a guy some time about and I believe they moved something like 10Watts of dissipation. Given that a tuned up Banshee could need to dissipate around 80-90HP of heat and 10W is .013HP, I have to say they are a total waste of hose clamps! On a side note, this is why engines don't cool as well in hotter weather. Warmer air around the exchanger means less btus or watts they can dissipate. Brandon Mull Engineering

It sounds like you already have the source of your issues. What I would recommend is use two small pieces of wire or make something to get your meter connected to the stator source coil right at the CDI. Unplug the CDI of course. From that point you should read proper stator resistance. Move your suspected areas and see if that reading changes. You can then pinpoint where the issue is. It is common for people not to check the plugs themselves but they cause issues, especially the ones Yamaha used back in the day that are less than weather tight. You will see copper sulfate (bluish) up in the plug. I have had them bad enough that we needed to carefully remove the sockets or pins from the plug housing and resolder them. You will notice somewhere VERY small lock blades that lock the sockets into the housing. Depress them with a needle device.

Did someone say REtard?

I guess clear enough. Doing a little market research. Not looking to produce any N2O systems, just curious right now. I figure more of the 4 poke crowd would be on the big single lungs.

I figured I would take a minute to answer a few questions on impeller installations. We have a lot of R&D in our impeller design to examine both optimal pump efficiency and failure modes of impellers and seals. The bearing to impeller shaft fitment would ideally be an interference fit (press fit) but is impractical on the Banshee due to design. For this reason, our shaft is designed to fit tight but not require pressing. If a shaft fits loosely, slippage between the shaft and bearing inner race may occur causing localized heating of the shaft which will then cause seal failures. When installing our shaft, it is common for the bearing to try and push out of the side cover just a bit so you need to make sure the bearing is seated once the impeller is installed. In some cases, you may need to tap the outer race of the bearing back in the side cover with a punch being careful to only strike the outer race. If the bearing pushes out a bit, this will cause poor clearance for the cross pin that drives the impeller drive gear. We recommend to install the pump all the way into the side cover, then tap it back out about .010" so the impeller blades are not making contact with the side cover housing. When installed correctly, the pump should spin absolutely free and you should not hear the impeller making contact with the side cover housing. Brandon Mull Engineering