blowit

assuming you have all the typical power adders like pipes carbs and all that, You will want low compression around 7:1 works good in banshees. weld the crank for damn sure, use an OEM head with a gasket and NOT a cool head, start with -2 degree timing, engine needs to be fresh. Brandon

:thumbsup: And honestly, even a snap off can read wrong. I think the biggest thing here is, " I hear something, I will just ride it until it quits making that sound, is that OK?" Brandon

Do what you want. Most do anyway but 75 is an alarming number. Post a pic of the harbor junk you bought. It is very possible that its only reading about 80lbs off accurate or so. That would be inline for harbor junk. If they only made surgeon tools so doctors could get a hook up too. Anyway, have it tested by a real tester for verification and I have posted this about 100 times now but compression does NOT mean your engine is good!!!! Piston slap will never show up on a comp test. If you decided to ride a slapper, go ahead and call the bank and get pre-approved for a loan to cover a new crank, and maybe some new cylinders when it pops. Sorry to rant. Brandon

Sux2BU. What i recommend is using some modeling clay to press into the threads of the flywheel if you do not have a tight enough thread pitch gage. After you make a positive of the threads, you can check that against the puller. I would bet you have the right puller buy some jacked threads. Be damn careful. Brandon

Lets just say that with basically stock trim motors, you will grow maybe 15psi between 64-biggest over bore. This becomes more critical with race motors and strokers. Hell, 1cc difference on one of our 7mm motors can change the ratio I think 8:1. Anyway, it does make a difference but not enough to really matter on a stocker. The ratio is good to know for estimating static pumping numbers and problems. You are right, static pressure balance is a must. we allow 5-7psi delta here and that is it. Brandon

Contraire young one. Bigger bore means a higher comp ratio for constant head volume. It does not equal much in this circumstance but does matter. The banshee is so friggin embarrassing on comp ratio, a little more will do nothing but help. Brandon

un-couple the lighting coil from harness. Black and yellow wires, remove the blue wire from the reg, remove all light bulbs, use an ohm meter to test from the harness side yellow wire to ground. If you have anything at all other than open line "OL", then you have a short somewhere. Before I went that far, I would test the output with the regulator plugged in. Use AC on your meter. anything under 11.5 is a problem and should be over 13. Brandon

Idle problem is probably because you either have a clogged pilot jet or the TORS system is doing its job because there is a throttle cable problem or not enough slack in the cable. This is allow the bike run normal until you completely let go of the throttle and it would kill the bike unless you get back in the throttle. B

Sounds like it is laying down and going flat from a lean condition. I would up the jet to a 220, check for flow out of the tank, and loosen the fuel cap to test for a vapor lock problem. this would not allow fuel to flow out of the tank and carb bowls would go dry in 2-5 seconds under WOT. Brandon

Let me know when you do so I can have my truck under you to catch it and take it home. Did you do the things I mentioned above? The washer will get you. Trust me, if you have an ignition problem, the problem will follow the wire. If you swap plug wires with no change, look elsewhere. Brandon

Well, .40 over and biggest piston before sleeve is .100, well I am sure you can subtract. The thing is not to bore unless there is a "proven" reason to do so. B

Then get rid of it and have it done right. The spacer causes problems with port timing and flow. I will not install them on any customer bike, even if they ask for it. just not a fan of them. Brandon

my eyes must be going but I see no spacer. Also mentioned is a 1/64 plate. That is less than a half mm and you would need a 2mm plate there. I have strong suspicion you got hosed on the 4mm. Possibly a 5mm long rod but no stroker. The next logical step is porting. I would pull it apart anyway so you know the condition and level of tune. Brandon

were you going to do what I told you? Brandon

not carbs, I think you already found your problem. Please use a propane torch with no flame and run around cylinder base to detect the leak. Them pull cylinder and replace gasket. If the case halves are leaking, you get to split them. It is common to have an air leak. The run on you experience is a tell tail sign and they do make a"special" sound with lean run on. If this was a TORS problem, you would not have idle. If it idles fine and you can verify that both carb slide drop to the bottom of the carb throat, proceed with above testing. Let me edit again. That would NOT even be a TORS problem but a carb slide or throttle cable problem. Everyone blames the TORS system because they do not understand it. It simply will trip out when there is something wrong. Removing the TORS, is just like solid fusing an electrical circuit because it keep blowing a fuse. There is a "reason" it blows. fuses do NOT blow for no reason. Brandon

Nope

washer under main jet missing, air leak at a mating surface, or ignition problems in that side. swap plug wires to verify, run propane gas around cylinders to check for air leak, then remove carb and find the problem. It is either leaning out or loading up and then firing. Brandon

I think there is a huge misconception that new rings means fresh engine. Unless you take the time to measure a piston against to bore it runs in, you are shooting blanks!! You can easily install rings today and still blow your engine to hell tomorrow by breaking the skirts off your pistons. If you don't know, you need to find someone that does or keep a piece of wood around to knock on. Piston tolerance is MUCH more important than ring end gap. I mean, do you really think the spring tension of the ring is what seals the massive combustion pressures? If a piston is loose, it will force abnormal wear on rings and not allow them to run square in the bore. Again, looks can be deceiving. The most common places for two stroke pistons to wear it at the bottom of the skirts and the ring lands at the top of the piston. Realizing that the piston plays a huge part in port pressure activity is key. I am not saying don;t re-ring, I am saying know before you do! Brandon

Not exactly. I think the ball was in motion before posting and this one will get rings and put back to bed regardless of condition. Brandon

Well going on looks alone will always get you in trouble. I always recommend that people mic things before just making a new hole for no reason but have found that most people do not know how to measure a bore. Even shops, because they would rather charge for a new hole. With this in mind, I recommend boring to be safe. Brandon

You will need a huge volume of air to do something like that. You must also maintain a constant pressure for tuning. You will need to introduce more fuel for that new oxidizer. I would say that unless you have the math at hand to calculate how much air, what volume, how much fuel, changes in air density, pressures, and such, I would not recommend playing with it. You either need big volume from what you get from a turbo, or a much more dense oxidizer like from liquid NO2. I have not done the numbers but I would bet on a range of 5hp increase for 30 seconds of run time. The think that will get tricky there is you will try to "boost" the intake with a regulator system. Unless the you have a throttling valve for cfm comp. you will not be able to regulate boost pressure very well. Turbos and SCs increase in volume and pressure with engine demand. That is what you would have to simulate. For what cost you might have in playing with something like that, might as well get a NOS kit and have fun. Brandon

You can test the coil in or out of the bike. Always remove the input, low voltage leads before testing. Brandon

The bigger pipe is not really to "expel" more gases, but increase the negative wave amplitude at the exhaust port and allow more room for expansion. What happens at the neg wave it it pulls the spent gases out put also pulls some of the fresh air fuel with it. The last phase of the pipe process is the pos wave hitting the cylinder with that extra bit of fuel. Think if the pipe as a "smart" supercharger. And since the reeds are closed, the pipe will boost density at the last second. The large bell on the pipe has nothing to do with getting rid of gases, just tuning of sonic air. Like an echo chamber. The diverging cone angle decides the neg wave amplitude but sometimes what we want and what will fit are two different things. Brandon

Isn't that kinda like asking which condoms "look" the best. Never mind function. Guess if the motor pops, it will smell good doing it. I would think cinnamon oil extract would smell the best but I am not sure about it's anti scuff properties. Brandon

Technically, pipes would change the running compression but not static. Because 2-stroke pipes use return wave technology, you will have a difference in air density in the combustion chamber after the return wave hits. This return wave effect is exactly why you might be looking at the CPI pipe. Return wave tuned at a higher rpm with a stronger pulse. This is why jetting, detonation, and HP, are all affected by the pipes. Anyway, unless you are on the ragged edge with timing or compression, you will likely have nothing to worry about and static pumping numbers will not change because you are not firing the engine to get a return wave from the pipe. Brandon