Motor surging

[motolink]

I started experiencing surging when I was using my cruise control or at least it was most pronounced when the cruise was activated. So I went through all the cruise control checks but every test was as per the specifications except for a check that involved getting the RPM to 2000 but every time I tried to get to 2000RPM the motor would go rev straight from 1750 RPM to 3000 RPM.

I turned the cruise off and tried turning the throttle to hold at 2000 RPM but as soon as it reached 1750 RPM the next slight turn of the throttle the motor went straight to 3000 RPM, I could not get the throttle to hold the RPM at 2000. it’s not a problem holding any RPM on the road.

Anyone experienced this, the bike travelled 40000km, not had the plugs or the fuel filter changed.

 

[Steel]

My first guess would be the throttle position sensor. It's basically a rheastat, and will usually wear out in the area it spends the most time.

 

[motolink]

How is the TPS tested.

 

[Kevin frazier]

My surge issue was only corrected once I followed the advice of the man in the tin shed and disconnected linkage to stepper control and set the rpm where I wanted it. It does go old Skool where you have to manage rpm until warm about a minute or so then she just idles as you set it. This correct my idle surge not trying to say this is your issue possible tps as Steele said, but for me it worked and I like old skool. Twist it

 

[Steel]

How is the TPS tested.

If you have TuneECU and a cable to connect the ECU to the laptop, you can test it there.

 

[motolink]

If the TPS is faulty will Tune ECU show a fault code or does it just read the closed and open voltage.

 

[Steel]

If the TPS is faulty will Tune ECU show a fault code or does it just read the closed and open voltage.

It reads the open and closed. Sometimes hard to diagnose just looking at the numbers. Mine was acting very similar, and took me a long time to pin down.

 

[Steel]

@Neville Lush @warp9.9 @Speedy
Now maybe we'll get some heavy hitters to come help

 

[Speedy]

Likely the TPS. But try clearing adaptation first. If still acting up, change the TPS. If not, start looking elsewhere.

 

[kenne]

had the same issue with mine, hooked it up to ECU TPS green. then it sorted itself for a bit then same problem again. replaced the TPS problem sorted right nah still doing the surging just not as bad replaced the idle stepper motor sorted. bike runs well now. Expensive lesson 3 hund for the stepper motor from the local trumphy stealer, but i do have a spare TPS.