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Yamaha FZ1 – Rough Idle, RPM Fluctuations & Vibrations (Need Help Troubleshooting)

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Horschd23

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Hey everyone,


I’m currently having some issues with my Yamaha FZ1 and I’d really appreciate your input.
(The Bike has around 73.000km - I know its pretty much, but I never had problems with it)

Here’s what’s going on:


  • When the bike warms up, the idle becomes rough and the RPMs fluctuate.
  • At cold start, everything seems fine, but once it reaches operating temperature, the problem starts.
  • The tachometer needle sometimes jumps suddenly, and the bike feels like it’s surging or hesitating even while riding.
  • Error codes I’ve pulled so far: 12, 33, 35, 36 (and 12 again).
    • 12 = Crankshaft Position Sensor
    • 33 = Ignition Coil #1
    • 35 = Ignition Coil #3
    • 36 = Ignition Coil #4
  • I already checked/charged the battery, cleaned the fuel system parts, and looked at some sensors, but the issue persists.

Additional context:


  • The issue appeared completely out of the blue – from one day to the next.
  • About a week before the problem, I rode ~2500 km on a tour without a single issue. Nothing indicated that something was about to fail.
  • When the problem started, I set off for a ride, and under throttle the bike began to “shake” – the engine felt rough and even the handlebars were vibrating when accelerating. I immediately turned around and rode home.
  • Earlier this year (spring), the spark plugs were replaced and the valve clearances were checked/adjusted, so those should be in good condition.
  • I also measured the crankshaft position sensor (Code 12) – resistance is around 380 Ohms, which should be within spec, so it seems fine.

What I’d like to know:


  1. Could this be related to the throttle position sensor, ignition coils, or possibly a MAP sensor issue?
  2. Has anyone experienced similar behavior on their FZ1?
For reference, I’ve also uploaded a short YouTube clip of the bike at idle, where you can see the tach needle jumping. It behaves exactly the same way when riding (the surging/zipping feeling).


👉YouTube link here:


Any advice, ideas, or things I should check next would be greatly appreciated. Thanks in advance!
 
I’ve checked all four ignition coils with a multimeter.


The primary and secondary resistance values are all within spec (measured cold at around 20°C).


So electrically, they seem fine in a static test
 
Not too sure given what you have done already. I had a camshaft pos sensor fail at around your milage. I would probably throw a part at it and put an oem crankshaft pos sensor in it. It may have failed and cause the coils to misfire or throw the code. If nothing else that is one thing you wont have to replace in the next 50-100k kms.
 
Horschd23 said:
Hey everyone,


I’m currently having some issues with my Yamaha FZ1 and I’d really appreciate your input.
(The Bike has around 73.000km - I know its pretty much, but I never had problems with it)

Here’s what’s going on:


  • When the bike warms up, the idle becomes rough and the RPMs fluctuate.
  • At cold start, everything seems fine, but once it reaches operating temperature, the problem starts.
  • The tachometer needle sometimes jumps suddenly, and the bike feels like it’s surging or hesitating even while riding.
  • Error codes I’ve pulled so far: 12, 33, 35, 36 (and 12 again).
    • 12 = Crankshaft Position Sensor
    • 33 = Ignition Coil #1
    • 35 = Ignition Coil #3
    • 36 = Ignition Coil #4
  • I already checked/charged the battery, cleaned the fuel system parts, and looked at some sensors, but the issue persists.

Additional context:


  • The issue appeared completely out of the blue – from one day to the next.
  • About a week before the problem, I rode ~2500 km on a tour without a single issue. Nothing indicated that something was about to fail.
  • When the problem started, I set off for a ride, and under throttle the bike began to “shake” – the engine felt rough and even the handlebars were vibrating when accelerating. I immediately turned around and rode home.
  • Earlier this year (spring), the spark plugs were replaced and the valve clearances were checked/adjusted, so those should be in good condition.
  • I also measured the crankshaft position sensor (Code 12) – resistance is around 380 Ohms, which should be within spec, so it seems fine.

What I’d like to know:


  1. Could this be related to the throttle position sensor, ignition coils, or possibly a MAP sensor issue?
  2. Has anyone experienced similar behavior on their FZ1?
For reference, I’ve also uploaded a short YouTube clip of the bike at idle, where you can see the tach needle jumping. It behaves exactly the same way when riding (the surging/zipping feeling).


👉YouTube link here:


Any advice, ideas, or things I should check next would be greatly appreciated. Thanks in advance!
Click to expand...
Coils are VERY moisturre vulnerable.
Had the same issues with my '09.
Replaced ALL FOUR with OEM coils and issue was gone. Don't bother with cheap coils!
 
moosecapades said:
Coils are VERY moisturre vulnerable.
Had the same issues with my '09.
Replaced ALL FOUR with OEM coils and issue was gone. Don't bother with cheap coils!
Click to expand...
2nd if changing coils go with yamaha oem .. i went with rm stator branded coils a couple years back chasing a rough idle. About 80% of people i had asked as well as reviews, etc, etc all said rm stator coils were good to great …huge and expensive mistake .burn ecu up cost a fortune just to have shop track down what actually was wrong after many failed “fixes” ..
 
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