cam positioning sensor FB 2015

Reply Subscribe

Thread Tools

Search this Thread

Mar 26, 2025 | 04:24 PM

Nelson Croes

Thread Starter

6th Gear

Joined: May 2016

Posts: 10

Likes: 0

From: Sint Maarten Dutch Caribbean

cam positioning sensor FB 2015

Hi all,

I had to change the cam shaft positioning sensor and after that my bike has a vibration. The engine self is not vibrating at idle but when I give gas, it causes the whole front end to vibrate.
Question, do you have to time your bike after the change of the camshaft sensor?

Thanks,

Nelson

Mar 26, 2025 | 10:12 PM

hattitude

Seasoned HDF Member

Joined: Sep 2008

Posts: 14,146

Likes: 11,219

From: San Diego, CA

Quote:

Originally Posted by Nelson Croes

Hi all,

I had to change the cam shaft positioning sensor and after that my bike has a vibration. The engine self is not vibrating at idle but when I give gas, it causes the whole front end to vibrate.
Question, do you have to time your bike after the change of the camshaft sensor?

Thanks,

Nelson

That depends.......

What year/model is your motorcycle...??

What does "FB 2015" mean in your title..?? I hope it's not shorthand for a 2015 Fat Boy...... a 2015 Fat Boy doesn't have a cam position sensor, only a crank position sensor (which needs no calibration after install).

I have to assume you have a '99-'01 Harley Twin Cam, or older EVO engine, if you still have a cam position sensor... Since we are in the softail section, I'll guess it's a 2000 Twin Cam, or an EVO engine bike.. I'll give info on both.

For an early Twin Cam:
The early Twin Cams had both a cam position sensor and a crank position sensor. When changing either sensor in an early Twin Cam, there is no need for any recalibration....
The only time I dealt with an early Twin Cam that had a bad cam position sensor, we removed it by adding a different ICM that only uses the crank position sensor..

For an EVO engine.
IIRC, the EVO cam position sensors have timing marks on them. There is an adjustment capability (one set of wide holes), but some are stationery (another set of fixed position holes). If the engine was running well and you are only replacing the cam position sensor, just mark the position of the old sensor, then install the new one in the same position.
It has been many years since I worked on an EVO engine, so if I remembered that wrong, I will surely be corrected.

I hope this info helps..

Others will chime in with more, and better info...

Let us know what bike we are taking about, and keep us posted..

Last edited by hattitude; Mar 26, 2025 at 10:27 PM.

Mar 26, 2025 | 10:28 PM

03fattyaz

Road Master

Joined: Jun 2014

Posts: 967

Likes: 588

From: Arizona

I’m going to assume he has a 2015 Fatboy and a wheel weight fell off.

Jul 22, 2025 | 07:47 AM

Nelson Croes

Thread Starter

6th Gear

Joined: May 2016

Posts: 10

Likes: 0

From: Sint Maarten Dutch Caribbean

HD FATBOY 2015 vibration intermittent engine(on and off)

Good morning to all Harley enthusiasts,

Ok I continue with my HD Fatboy 2015 vibration problem. I have changed all the exhaust sensors and cleaned all the intake sensors and fuel injection system.
The vibration has gotten less, but now it is intermittent. The engine will work fully ok without vibration and after a few minutes vibrate again.

Therefore I do not think it is a crankshaft issue like I was thinking. Obviously I am not a mechanic nor do i have experience with bike engines, I love to ride my bike when it functions at top level.

My question is to those with experience, all this vibration started after the crank sensor was replaced. Can it be that the crank sensor was/is not correctly installed?
Do I have to buy a new crank sensor and see if this vibration stops? Please explain it to me in simple in layman's term.

Thanks for you all that have tried to assist me.

Nelson

Jul 22, 2025 | 11:40 AM

hattitude

Seasoned HDF Member

Joined: Sep 2008

Posts: 14,146

Likes: 11,219

From: San Diego, CA

Quote:

Originally Posted by Nelson Croes

I'll mention the second highlight first.
Your crank sensor should not be the cause of your vibration. It reads the flywheel, tells the ECM where the crank is positioned, and that allows the ECM to know when to tell the coil to send spark to the plugs... If the new one you put in was defective, the bike wouldn't start.

If it the vibration started after you installed the crank sensor, it may be something you touched, moved, or bumped when installing the crank sensor. It never hurts to check your work, namely the crank sensor connection, and anything you may have affected while installing it.

You report you changed exhaust sensors, cleaned intake sensors, and cleaned the fuel injection system. After doing that, the problem was better, and now just intermittent. That would suggest to me that you have a sensor issue and/or fuel issue.

I would check the sensor wiring you handled when cleaning the various sensors. Looking for connector issues, and possible wire issues at, or near, the connectors you handled.

Is your Check Engine light constantly lit (current diagnostic code)?

Does your Check Engine light go off when the bike is started, then come back on for about 4 sec after started, only to shut off again (historical diagnostic code)?

Have you looked for engine diagnostic codes?

If you have a code, which at this point may be historical due to the now intermittent nature of your issue, it could point you in the right direction...

Keep checking, in the end, it all boils down to spark, compression, and fuel...

Let us know what you find..

PS- one last thing, vibration can come from the exhaust rubbing, or hitting the frame/engine, etc. You were working around the exhaust with both the crank sensor replacement and the exhaust sensor change. You may want to check the exhaust for proper alignment, no loose heat shields, etc, to ensure the vibration isn't mechanical in nature.