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About A.J.K

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  1. A.J.K

    Yz450f 2015 FI problem???

    Try measuring TPS ohms when it's warmed up. I had a hard to diagnose running problem with my 2011 YZ450F last year. It always started acting up after engine warmed to the operating temperature. The GYTR tuner didn't show any codes. At first I tried cleaning the injector, replacing the fuel filter, measuring TPS, replacing the fuel pump, cleaning all the sensors, etc...but nothing helped. But when I measured TPS when it was warmed up, the ohms were jumping all over the place. After replacing TPS the running problem went away. I rode the bike a couple months without issues and then sold it.
  2. A.J.K

    Erratic Idle '14 450

    Just an update on my 2011 YZ450F: - switched over the 2 pressure sensors (they have the same part number). Didn't make any difference so the sensors must be ok. - had the injector professionally cleaned. According to the report the injector wasn't blocked in any way. At this point the idle problem was so bad that the bike was pretty much unrideable. It stalled as soon as I let off the throttle. - changed a new fuel pump (just the pump, not the whole assembly). The idle was back to normal and the bike seems to start much better than before. So far I have ridden the bike twice and the idle is still normal.
  3. A.J.K

    Erratic Idle '14 450

    Well, yesterday idle RPM started to drop ramdomly again. So my bike was problem free for about 10 hours of riding time. Today I removed the pressure sensor and cleaned it thoroughly. I also inspected the hose that connects the sensor to the throttle body and there weren't any cracks. Cleaning helped a bit but didn't solve the problem completely so I guess the sensor is going bad. The next step is to get a new sensor. It seems that lately other people have had idle problems too...
  4. A.J.K

    Erratic Idle '14 450

    Hello! I've been reading this forum for many years but this is my first post. It is normal that GYTR tuner shows TPS value between 0-80.That is not your problem as long as value changes smoothly when you twist the throttle. I think you should try cleaning the pressure sensor on the throttle body. I had problems with erratic idle on my 2011 YZ450F since last August: sometimes idle was too high and sometimes it was too low and stalled, but otherwise the engine ran perfectly. The tuner didn't show any codes. Valve clearances were spot on and I cleaned the fuel filter and injector but that didn't help. The problem got progressively worse until I tried cleaning the pressure sensor. I just disconnected the rubber hose from the sensor and sprayed the sensor with carb cleaner. After that the problem went away and hasn't come back.