Top end WAS noisy on my 120ST---FIXED IT!

Spazz

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Feb 22, 2014
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Since day one, my 120ST has been noisy on the top end and was very prominent when hot... especially between 2600-3000 rpms. I was told it was NORMAL and had dealt with it day by day.... I wasn't buying it. There is no way I should here top end noise at 80mph over an Arc XDI 600.4 amp pushing 4 high-end speakers.

I found out about ROCKOUTS on another forum a few months ago and decided then, that this could be a viable solution ( to correct a potential problem ) that I 'might' be having.

It never got better or worse... so I bought the $15 rockouts and hung them on the bench in the garage for a rainy/snowy day.

I picked up some adjustable pushrods and yesterday decided to tear into it... GLAD I DID!

Once I got in there ( following the manual ) and took the rocker support housing off the rear cylinder, it was obvious that 'something' just wasn't right.

20160218_114613.jpg


First clue was the right side bolt on the exhaust side.. VERY HARD to get out compared to the other 3

20160218_090326.jpg


Second clue was the offset position of the rocker shaft itself...

20160218_090335.jpg


Third clue was noticed looking into the bolt hole of the rocker support....

20160218_090411.jpg
 
Fourth clue was the rocker shaft when I pulled it out of the housing with very LITTLE effort.... witness marks from rotational action

20160219_090557.jpg


( they are not supposed to move this easy )


Here is a video...

[video]http://vid853.photobucket.com/albums/ab94/tgrisko/15RGS120/20160218_113003.mp4[/video]

After finding all this... I called my HD tech and sent him pics... and told me to bring the parts in for inspection... afterall... only 3000+ miles and still under warranty ( I was 'cleared' by HD on this before I started )

Everything was within tolerances but it was clear to them that this had to be what we were hearing in the top end.

They agreed with me installing the Rockouts should cure the issue of the shafts bouncing off the bolts and moving around during operation.

20160218_113420.jpg


After cleaning up and re-installing the shafts and aligning them, I installed the kit with ease... instructions are perfect and very simple.

Here you can see the ROCKOUT inserts installed.

20160219_091311.jpg


I reassembled the rear cylinder with the new SE adjustable pushrods and took the advice of my HD tech to go 3 full turns on the rods vice 2.5 as stated in the instructions. He said the tighter tolerance will run better and quieter.... he has been an HD tech for 15+ years, so I trust him.

I did the front cylinder and found the same issues....

Got it all back together... and......

WOW!!! I have NEVER heard my 120ST so quiet since day one!!! Every bit of noise I was hearing is GONE! I ran it up to around 285 degrees at idle to get the oil nice and hot and rev'd to 2600-3000 rpms where the noise was most prominent... NOTHING AT ALL!!!

I couldn't be happier at this point! Gonna be takin er out today for a ride, so that will be the ALL-TELLING truth.....

Just wanted to share this with the masses.... you never know who this may benefit since this ROCKOUT KIT as helped several hundred big twin owners from stock to wild builds
 
Nice work! Glad to hear rock-outs work for loose rocker shafts.

What gaskets & seals are needed for the job?
 
You Da Man Spazz! Great article write up and thanks for sharing!
 
Nice work! Glad to hear rock-outs work for loose rocker shafts.

What gaskets & seals are needed for the job?

Rocker cover gaskets and tappet block gaskets ( if you inspect the lifters/cams) The O-ring sets for the pushrod covers should be good for you, but they all came with the SE adj. pushrod kits, so I just changed them out.

Oh... there is a VITON O-ring that gets replaced... and it's under the rocker supports... the ROCKOUT KIT supplies both O-rings!!!!

There is a breather within each rocker box... and the book says to replace the seals, but when I talked to HD, they said not to worry about it since they are bathed in oil anyway, so I didn't mess with them much ( the breather is the teardrop plate in the middle of the rocker supports with an element inside... I didn't touch these, just removed the bolts and let them lie in the supports )
 
Thanks, Spazz. Great stuff.

No problem! FYI.... the origination of the ROCKOUTS all began because of a noisy top end on a 2015 Limited... The owner's persistence paid off in this solution! A machinist by trade, he now sells these kits ( even on Amazon ) and has helped hundreds of owners resolve the 'tapping' top end

You can read his story on his site www.rockout.biz

Here is his video upon discovery

 
Great write up brother so this could help a noisy stock 103 also ??
 
Great write up brother so this could help a noisy stock 103 also ??

Absolutely! This all started with a noisy 2015 Limited Lo last year.... If it can be determined that the rocker shafts are making the noise, Rockouts can solve the issue....and the ONLY way to know is to get it apart...
 
I reassembled the rear cylinder with the new SE adjustable pushrods and took the advice of my HD tech to go 3 full turns on the rods vice 2.5 as stated in the instructions. He said the tighter tolerance will run better and quieter.... he has been an HD tech for 15+ years, so I trust him.

Just curious. What is the thread pitch on those push rod adjusters?
 
Just curious. What is the thread pitch on those push rod adjusters?

Ya know.... the instruction sheets doesn't call it out for you... DANGIT! I should have checked it, but by remembering... they have to be at least 20-24...

Here is a close up pic of the pushrod and a 5/16" wrench on the adjuster

SE%20pushrod.png
 
I think that they are 24 pitch. So three turns is 1/8 inch pre-load which is OK.

Now you can go back to some good synthetic oil;)
 
Great work Professor SPAZZ. This whole thread is like goin' to school (Like most of your posts).
Much appreciated.
 


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