I'm working on a 1200 monster which is doing my head in. Bike revs well until 7.5 k then just dies off in all gears as if the throttles were closing. That is the neutral max rev limit, but seems to be active even when the bike is in gear. Clutch switch is working, side stand OK, exhaust flap OK, and the estimated gear is correct. Tank cleaned inside but very clean. Anyone seen this before?
so fuel filter ok/within service time? if cut-off is consistent then clogged filter a definite possibilty
Fitted with map sensors which seen to be showing the expected readings. The etv is showing as closing above these revs. Power graph up to 7.5 k is exactly as j would expect then it just gains revs gradually. It was remapped a couple of years ago, uploaded a stock map with no difference
That was one of my thoughts, but normally with a blocked filter it would rev in lower gears but not this case . I would change the filter anyway but its not listed separately. £700 for the pump
i haven't had a fixed pattern experience over the years as regards low gears/high gears, I can remember cars that wouldn't do either (high or low). I agree - some "routine" bits for this bike are a bit of a pain .
Check your exhaust flap is opening. I had this happen on my Multi 1200, it wouldn’t rev over 7.5k and that was the problem for me. Took off the cable and fixed it open; boom!
Are the throttle valves actually moving towards the closed position once 7500rpm is hit or are they staying static at whatever degree opening they are - I would guess about 70 degrees give or take a bit? With the engine off does the TPS move all the way to 90 degrees as the APS moves to 100%, or does it not go past a certain number of degrees? Have you checked the voltage output on the signal wire from the TPS back to the ECU? Is it as expected and does it change smoothly as the twist grip is turned open/closed? Something is obviously sending a message to the ECU to tell it not to open the throttle valves any further. Perhaps the ECU thinks it’s in neutral even though it’s in gear? Perhaps there’s a dead spot on the TPS potentiometer and the ECU thinks it’s opened the throttle valves fully when really they’re only open 2/3rds. What do the injector pulses look like as revs increase? Are they open long enough to deliver sufficient fuel to continue an increase in revs?
Have you read for any errors or seen any warnings on the dash? The 821 and 1200 can go into limp status if there’s a problem with the APS, the throttle unit. They can and do play up. More so than the other bikes with RBW. You could try a reset with diagnostics, or replace with new. That would need a calibration with diagnostics also.
Thanks @West Cork Paul and @nelly. At standstill the tps stays shut no matter what the aps is showing. Its a very strange throttle body in that the tps is part of the body itself and cannot be bought separately. Bought another unit and transplanted the tps with the same results. For this bike texa does not have an option to open the throttles manually. The throttles actually start to close over 7.5k and about 25% opening. Tried all of the resets with no joy. Even though the aps seems to give a smooth opening with no dead spots i have sent for another one so let's see if that helps.
Do you have Texa? With the engine off but ignition on the physical throttle valve won’t move as you turn the twist grip but the TPS will react. You’ll see APS values and TPS values in Texa, they may be 2 track on that model (can’t remember it’s been awhile since I had a 1200 monster here) but you should see the changes in both values. Before throwing money at a new APS, can you back probe it to see what voltages come off it back to the ECU?
There are 2 APS voltage readings, as Paul mentions. One will be either half the voltage of the other, or they will read inversely as you open the throttle. If one of the tracks is playing up, the voltages won't follow convention and the ECU will go to limp status. It's a safety net thing to avoid the throttles effectively "sticking open". The TPS will have the same setup, and while they can fail, the APS is far more common.
Are these bikes ‘ride by wire’. If so what you are calling the TPS is actually the throttle actuator motor. Is is likely that some sort of TPS equivalent is built into this.
Yes Chris. They are RBW. Each throttle body runs independently with the TPS info being returned by the actuator unit.
Yeah, the APS (accelerator position sensor) is a potentiometer at the twist grip. The TPS (throttle position sensor) is a potentiometer at the throttle bodies. The APS feeds the rider input/desired torque to the ECU via a varying voltage. The ECU then knows, depending which riding mode is selected, how much to open the throttle valves in the throttle body. The throttle valves are actuated by an electric motor controlled by the ECU. The TPS, which is mounted on the rotational shaft of one of the throttle valves, feeds back info (a varying voltage) to the ECU as to the actual position of the throttle valve so the ECU knows whether it should open, close, or hold static, the throttle valve. With a 2 track system the sum of the 2 voltages coming from the APS or TPS should add up to 5v, with, as Nelly said, one track increasing the other decreases but always maintaining a sum of 5v. That explanation is for anyone reading this thread really, not you specifically Chris for when it comes to electrics you know your stuff.
