Engine Noise

777Nor · Mar 2, 2015

I've got a ST1300 that's making a knock/rattling noise. It starts around 4k rpm. It doesn't get any louder or go away as he rpm's climb. Just gets harder to hear because of the normal engine noise. Its easyier to hear under load, but can be heard sitting still. At 4k when it starts it can be overheard over everything.
Bike has 20k on it
List of things that have been checked.
Oil, for metal
Cam chains & tensioners
Clutch & primary gear
Primary output shaft
Cams & valve train
Compression
Changed fuel, made sure it was 93 octane
I have a sound bite but its not in a file the will upload.
Any ideas?
Ron

STDaveNW · Mar 2, 2015

My 2004 has 55K on it and is significantly louder than it was new. Grumbing from the front of the motor. Seems like it started after 5 years ago after I replaced water pump, but I also had the clutch out and basket. Only has to last me another year, then i'm giving it to my son-in-law as there is a Road King and FJ in my future.

vinny · Mar 2, 2015

Exhaust clamp?

Al Gully · Mar 2, 2015

Pull the clutch handle in and see if the noise goes away.
Mine is significantly quieter with the clutch handle pulled in.

Igofar · Mar 2, 2015

Have you changed oil type or weight?
A TB sync may also smooth things out.
Check the plugs? Top tier fuel-ethel?

777Nor · Mar 2, 2015

Same noise with or without the clutch engaged.
We ran totally fresh gas in it, even added octane booster in it.
On the lift with the bodywork off it sounds like its coming from the clutch area.
Its a police fleet bike. So it gets worked hard.
This might help.
http://youtu.be/YSIBgC11p6o

BakerBoy · Mar 2, 2015

It might be the clutch, but upon hearing the sound in your video, I wonder about something outside the engine loose and rattling. Such as any of the Tupperware at joints, an exhaust header, any number of brackets or frame bolt-on pieces (cowl stay or tip over frames, for example), or a broken valve cover bolt. I also wonder if perhaps one of the cam chain tensioners isn't engaged. What work was done when it started?

vinny · Mar 2, 2015

Get a can of seafoam fuel system cleaner and put 1/2 can in a full tank, run it out and then repeat. Could be dirty injectors causing uneven performance. The 1100 can do something similar with dirty carbs.

cornSTalk · Mar 2, 2015

Go buy or borrow a mechanics stethoscope and listen at various parts of the engine at different rpm's. This will help isolate the area where the noise is coming from. Good luck as the noise sounds like it needs your attention.

Al Gully · Mar 2, 2015

Igofar said:
A TB sync may also smooth things out.

What type of oil and grade do you currently have in the bike.

777Nor · Mar 2, 2015

cornSTalk said:
Go buy or borrow a mechanics stethoscope and listen at various parts of the engine at different rpm's. This will help isolate the area where the noise is coming from. Good luck as the noise sounds like it needs your attention.

I own one. The noise is loudest from t cutch cover.
Oil is 10w30 syn blend.
The motor runs great. No loss of performance.
Spark plugs look correct.

777Nor · Mar 2, 2015

jfheath said:
Check the counterbalance shafts adjustment. Although only knocking at above 4k is an odd one, its worth while eliminating this as the possible cause. Its an easy job and there is some info here .

I use a screwdriver to the ear and adjust with the engine running, with the blade of the screwdriver on the end of the shaft. They need to be adjusted somewhere between the high pitched whine and the rattle. If they are a bit out, you'll be surprised at what a difference doing this little job makes.

Yup been there done that.
There are two ways to set the counter balance shafts. Done both. No change.

st1300marc · Mar 3, 2015

I think my bike makes a similar noise under 2500rpm if the throttle is opened too far but I think this is just because I'm lugging the engine.

Your noise sounds more like a rattly cam chain in my admittedly limited experience

st1300marc · Mar 3, 2015

I just found this and actually the noises are different

honda st1300 chain tensioner?: http://youtu.be/o5yalZJPp0U

cornSTalk · Mar 3, 2015

As BakerBoy mentioned previously I am wondering about an engine mounting bolt being loose or broken. Check all mounting points with a torque wrench to make sure they're up to specs. A broken bolt might look ok but could be broke off. Hopefully it is something simple and is just being overlooked. Also did the noise start all at once or has it slowly been getting louder? If the mounts all check out I think I would be double checking the clutch and related components.

777Nor · Mar 3, 2015

He just noticed it when he was doing a escort. When through two tanks of fuel before he brought it in.

Igofar · Mar 3, 2015

I service alot of 1300p motors...I would start with the TB Sync and new hoses.
.02

777Nor · May 6, 2015

Spun #2 rod bearing.
I'll post pics of the engine rebuild soon.

Honda-st-team · May 6, 2015

Can't wait to see the pictures

jjoyce2 · May 6, 2015

Ouch.

What a tank. Engine keeps workin' well enough that he burned two tanks of fuel before taking it in...

Engine Noise

Dave

It's all small stuff.