Horizons Unlimited - The HUBB

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ajax 22 Jul 2015 04:31

I had a long thread on here awhile back regarding head noise.
In summary when motor starts warming up about 45-60 sec the rgt side exhaust lifter starts a strong tapping sound. I can mimic sound by hand with tappet. Lifters have been checked and adjusted routinely. Rocker head has been removed and inspected as well.

With that said it has over 2500 miles since i've got it back on the road and has proven very dependable :). Just noisy and industrial sounding.

But its in the back of my head that it will get worse and I don't know if its a good idea to just replace the suspected rocker arm or replace the whole rocker head.

jjrider 22 Jul 2015 06:12

I've been looking at some of my rocker covers and rockers and have noticed some of the shafts that the rockers pivot on are a little worn to one side from the rocker. I'm guessing those are the source of some of these rattling rockers. Doesn't have much danger in breaking or any unexpected issues, just noisy. May slowly get louder as they wear more . I'm having a couple complete shaft/rocker sets coated with a diamond based substrate that'll eliminate the wear plus reduce most friction . Also have a cam with them to get coated , it's supposed to eliminate 90% of the drag and not "need" lube , so if ever low on oil , there won't be any damage , at least not up there . I don't plan to test that part. Also have a set of valves being done with the coating on the shafts.

If you grab that rocker to check it, see if it'll wiggle on the shaft itself, that'll tell you if that is the cause of your noise. Otherwise with the cover off you can remove the shaft and inspect it, there should be less than .001" clearance between the rocker bore and shaft.

ajax 22 Jul 2015 12:51

The questionable rocker: the spring that holds it on shaft and creates tension is worn further then the other 4 rockers.
It has less resistance to up and down movement, no drag. It has more movement on shaft.
If I move and release it, it will fall with no resistance. The other 3 rockers have the resistance.

All else looks fine with it including contact area at tappet

jjrider 22 Jul 2015 15:31

With that bolt holding the rocker shaft in you unfortunately can't change the spring without the cover being removed. I know the cover I used on my present motor had some "free moving" rockers and it also clatters , will be fixed soon.

You'll just need that spring and maybe a new shaft, if not the rocker also to tighten it up.

xtrock 22 Jul 2015 19:55

Quote:

Originally Posted by jjrider (Post 511252)
With that bolt holding the rocker shaft in you unfortunately can't change the spring without the cover being removed.

What you mean here, he already have cover off?

jjrider 22 Jul 2015 23:20

doh:

:oops2:

:innocent:

:wheelchair:



Alzheimer is kicking in


then it will be no problem changing it .:thumbup1:

ajax 22 Jul 2015 23:22

:)
cover is off and on the table

charlesm87 27 Jul 2015 19:46

If the frame on the XT600 is the same as the E model then you can get the head off without tilting the engine. Rocker box cover is a pain but i've put a previous post here with details how to do it. Saves much time and hassle.

turboguzzi 27 Jul 2015 21:38

thread's a bit all over the place but lets give it a try :)

looks like PO was a bit of a butcher.....

would def try to mill the head surface to get rid of any grooves, specially where the metal ring of the gasket makes contact. at least here in milan a single resurface like that would be no more than 25 euros...

valve seats in the xt600 are kind of far from the surface so you could mill off quite a bit and compensate with two or a thicker DIY base gaskets.

whatever you do, use an MLS (multi layer steel) gasket rather than the stock old school klinger/metal (like in your pic) for the head. much more reliable and easy to get off if you need to re-open. Cometic or Athena or Prox shoudl make one like this

http://www.ebay.it/itm/KIT-GUARNIZIO...item234ac4d5b4


maybe post some pics of the rocker. if the sliding area is damaged then buy new or reweld and grind.

ajax 31 Jul 2015 03:57

https://www.dropbox.com/s/vfj0e3815k...t600A.jpg?dl=0I called a bike shop that was recommended from my local shop. Guy at shop told me to just get some 200 grit emery cloth with a straight block and sand it down a bit. Then put it back together and ride....

He didn't see the picture of the head but didn't think it would be that big of a problem.

I'll try to find a machine shop to have someone actually see the head.

Bobmech 31 Jul 2015 10:16

He obviously didn't see the pic, if he did he wouldn't have recommended sanding it with 200 grit on a block.
The head needs machining.

Bob

jjrider 31 Jul 2015 12:00

Or he was the previous owner that put it together that way :laugh:

With a normal head that would be fine, just not with gouges where they are.

ajax 3 Aug 2015 03:40

I'm going to take it into a machine shop this week to see what can be done.
If I go with another head (different bike) do you think I will have any problems?
Another head with my rocker box.

Bobmech 3 Aug 2015 10:50

If you go with another cyl head, you must get the head and rocker box & use them together as they are "matched". When they are manufactured they are bolted together & align-bored for the camshaft.

Bob

jjrider 3 Aug 2015 15:15

Yup , mixing those 2 isn't a good idea , I'm sure some can work, but many definitely won't.


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