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About jaguar57

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    motorcycles, alternative health

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  1. Now the fun part is seeing how worn the piston/rings and cylinder is
  2. jaguar57

    2004 RM250 Jetting Help

    Pro Circuit suggestions or even leaner since you're at 750 ft. going that lean on the idle air screw may mean the jet for the needle is wore to a bigger size and letting too much fuel in when the throttle is closed. I've never replaced one. I think they have to be pressed out. What engine oil are you using?
  3. jaguar57

    Jet Needle & Needle Jet

    On some big bores they tend to wear the hole bigger after some years but normally they tend to last nearly for the life of the bike. If you wind up having to use an extra small idle jet then that may be a sign that the jet for the needle is wallowed out and letting too much gas flow past it at idle and just above idle.
  4. Here's my page on this subject: http://www.dragonfly75.com/moto/selectNed.html
  5. OK now I did a flow analysis and found out the most stable gas/air ratio will be had when the needle jet open area at 80% throttle open is equal to the main jet hole area.
  6. I need carb data from engines that have a perfect chocolate brown color to the spark plug. If your jetting is a bit off then the color will be lighter or darker and your data is of no use to me. Also the data needs to be from engines that use the full rev range not from riders that just do low speed trails. I have a theory that if verified should be of use to everyone who wants perfect jetting. The theory is that at a certain percentage of slide opening the area around the needle at its jet is equal to the main jet area. On one of my engines that runs perfectly that percentage is 60% but I don't know how common that is. Getting that relationship right means you get the needle taper right. Selecting the right needle is the hardest part of carb tuning. Those that participate will receive the following Excel spreadsheets: Oil Ratio Calculator - shows you the correct fuel/oil ratio to use depending on which oil you use, type riding, and max RPM. Carb Flow Calculator - shows you the max flow velocity and where that falls within the range designed for enduro to MX bikes. Carb Needle Calculator - shows you if your current needle has the ideal taper (once I get it finished) Just message me after you've posted your data. Needed: Carb brand, throat size, idle jet size, main jet size, needle ID, needle clip position, fuel/oil ratio, type gas used (does it have ethanol?) thanks guys ps- I know some people think that this is just legs on a snake but let me tell you my story. I bought a bike and changed the idle and main jet so it ran really good and gave a perfect colored plug and ran really crisp all thru the rev range. But it had an odd lack of effect past 3/4 throttle. I finally figured out that the needle taper was too steep which fully engaged the main jet too soon. If I would of had some guide that dictates how the taper should be then I would of known it was off. So I want to figure out a standard to help others out. My bike is a commuter bike and its very possible this is a trick the factories use to limit power on the street. So this will help many people who are trying to get the best power out of commuter bikes. Also it will help people who are putting a different carb on their ride. Carbs are sold with a certain set of jets and needle. But on different engines then the main jet would be resized and so should the needle so the main comes on at the right % of throttle opening. Look at this graphic showing the amount of effect of the main and the needle and how their effects are equal around 60% slide opening:
  7. jaguar57

    YZ250 - tuning help

    Guys, it isn't about burning or not burning the oil. I say that because combustion temp is around 1000*C and the oil burns at a much lower temp, so almost all the oil burns with the gas but can leave some carbon residue. The more synthetic an oil is the less carbon you will see inside the pipe header. The exception is that some gas/oil is not atomized and is in droplets which don't burn right away and some may make it to the pipe without burning. So that adds oil to the spooge. Also just oil that is scraped off the cylinder by the rings. Also oil droplets coming up through the transfers from the crank oil pool (as the crank wheels sling some up). So basically the more oil in, the more oil out. Synthetics greatly reduce that by allowing high fuel/oil ratios (less oil) but then those high ratios allow less engine power because of less ring sealing. So if you want the best power and best protection use a synthetic/mineral blend at a moderate ratio but be prepared for some spooge. If you hate spooge and hate cleaning off carbon deposits then use a full synthetic oil. My page fully details each of the popular oils at www.dragonfly75.com/moto/oil.html and my calculator allows you to know what a good ratio is for each oil according to max RPM and type riding.
  8. jaguar57

    YZ250 - tuning help

    I think it's nonsense to talk about the oils flash point temp. why? Because that reflects how much "lightening additive" (something like a very light kerosene) there is in the mix to lighten it up to make it more pourable. That's typical with synthetic oils. The only flash point that's important is that of the base oils and they are pretty much the same except for the cheaper group 1 oils some mixes have. So forget "flash point". It means nothing because they don't list the base oils flash point. the kerosene-like additive with a low flash point quickly vaporizes and leaves the base oils on the parts. It is their flash point that would have any importance and that isn't listed in the specs. For competition riding use a castor blend or a synthetic blend (combo synthetic and mineral oil) so you can have the fuel/oil ratio close to 30:1 For trail riding use a synthetic oil so you can have a high fuel/oil ratio. Check out all the info on the subject at www.dragonfly75.com/moto/oil.html
  9. jaguar57

    Hello world, I got problems

    adding resistance would lessen the current draw from the stator which would lessen the power it is required to produce
  10. jaguar57

    Hello world, I got problems

    &%$#@! this GD headache! just southern engineer a solution. Cut the non-grounded wire from the stator to the CDI and solder in a 5K or 10K potentiometer. Turn it to present zero resistance and then start the bike and once it is idling on its own then turn the potentiometer dial to increase resistance till it interferes with normal idling (indicating it has reduced voltage to CDI too much). Turn it back a bit from that setting and disconnect it from the wiring (being careful not to change its setting) and then measure its resistance and then buy that value of resistor with a 1/2 watt rating and hard wire that resistor in.
  11. I thought Saber was made for weed-wackers and the ratio they recommend is for weed-wackers. Farmboy the way to tell if an oil (and the ratio) is good must include how fast the rings wear (till the end gap requires ring replacement) which you excluded in your assessment. Too many good oils to use so why use saber?
  12. jaguar57

    Hello world, I got problems

    shorting out the output of the ignition coil might burn the coil out but I'm not sure. But it won't affect the stator coil because it is two steps removed from it.
  13. jaguar57

    SX65 bottom end seized

    KTM is full of shit when it comes to oil. Please tell me what oil you are using and I'll tell you if it is truly fully synthetic and what ratio range is normal for said oil.
  14. jaguar57

    SX65 bottom end seized

    you went up a piston size without using a feeler gauge to check piston/cylinder clearance and then you got what you deserved, a seizure. and probably you have deceived yourself with product promo about how good the oil is that you are using.
  15. jaguar57

    Hello world, I got problems

    no way the bottom case can overheat in a few minutes. electrical problems can be a gradual death. trust me