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#16 |
Join Date: May 2021
Posts: 351
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ProDigit, two questions, I see from above what tire pressure you’ve been running, what is the maximum pressure stated on the side of your tire? That’s question 1 because my Hawk 250 DLX manual calls for 40 psi on the rear tire and the tire itself says 32 psi max. I do believe the manual may be incorrect. Second, your post above you use 0.04-0.05” I’m sure you meant.004-.005” right? If you changed the intake to .002” it would be quieter and cooler, I agree. Was looking at your thread and sounds like your having fun with the bike. My thoughts
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#17 | |
Join Date: Aug 2013
Posts: 271
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Quote:
I was thinking in mm, writing in inch. The outside tire of my Lifan Xpect stated 40psi. I'm running roughly 35psi cold, and 38psi hot,both front and rear, 1psi tolerance. The bike can actually run fine at 10psi, but really needs a good 28-30psi minimum, to roll efficiently. |
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#18 |
Join Date: Aug 2013
Posts: 271
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The Xpect runs way too lean in hot climates.
I was thinking of install an oil cooler, but recently I've discovered a sine generator that can be plugged in instead of the O2 sensor, called a dummy plug O2 sensor. I bought it off eBay and will do tests with it. The O2 sensor will basically be unplugged, and instead the dummy plug will be plugged in. The device contains a +12v, ground, and data (0.1-0.9V) wire. It generates a 0.9v pulse, I'm guessing the adjustment dial adjusts the width of the pulse, causing a higher or lower overall voltage (depending on how it's set) than ideal (0.45V). The average voltage is the average of the peaks (0.9V) and troths (0.1V). The stoichiometric value is 0.45V average. When the fuel injection system reads this value, it will determine that the current mapping is too rich, and will try to lean out the mixture more. Without actual wideband O2 sensor data, I can presume it wants to lower from 14.7:1 to more like 15:1 or 16:1, so it will be expecting an o2 sensor value of closer to 0.5V (estimated) or higher. I'm just not sure if the EFI system on the Xpect will continue to try getting that signal from the dummy O2 sensor, until it runs so lean the bike will stall, or if there are limits to it's adjustment curve. Considering that the signal is a pulse, I can presume the EFI will variate only a a bit off of the dummy plug signal, and that increasing or decreasing the mean voltage value will result in a small offset from the ECU. Anyway, I'm presuming setting the value above 0.45V, but below 0.9V will make the bike run richer, and in theory trick the bike into believing the exhaust is running lean, when it's actually running stoic. Issues I can forsee is that the bike may run better at certain rpm ranges than others, like better idle or low rpm response, but worse in the mid-rpm range; or some similar deviation. From what I read, the EFI system will go off it's closed loop system, and run stoic from 75-100% throttle. In other words, the system won't look at the O2 sensor values above this point. This makes me believe that the stoic values of 75-100% throttle will become lean values when an open (more freeflow) exhaust is installed, which can be dangerous when riding longer at higher speeds. |
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