CB550SC Engine Tick

I have recently bought a Honda CB550SC Nighthawk in need of a little
work at a very reasonable price. One of my pproblems is an engine tick.

The ticking noise I hear is very simialiar to that of a tripping relay
(at least thats the only thing that I can compare it to) and is not
hard to hear. It is about as loud as the bike itself.

The noise is very consistent (seems like it sounds every 4 revolutions
or so), it doesn't really get any louder at higher rpm levels either.

I read in these forums about a month ago that it could be the lifters
if any air was to get into them. The previous owner had put in new cams
recently. So I currently have the engine apart awaiting a gasket to
piece it back together.

Also while taking the cam holders out I found 1 "just about broken" cam
holder bolt in the same area as the tick (it seemed to be around the #2
cylinder), and the cam itself was worn a little more in this area. When
I say almost broken it seemed to be twisted and I actually snapped it
in half (no I'm a not a bodybuilder ).

I know I have to bleed that lifters anyway, but everyone around my area
that I have spoken to says I should get new lifters (not and easy or
cheap task) as one of them must be gone in order to make this sound.
I'm hoping that it's either one of the two problems I found (or maybe
the broken bolt could have let air into the lifter?).

Anyways any feedback would be greatly appreciated. Thank you in advance
for any help.

Matt

 

"Every 4 rev.s" or every 4 pulses?
- betcha a shiney new nickel its a valve out of adjustment.
Check those clearances before winding her up too
tight, (especially if , as you say, the noise is loud).
MadDog - "R75/5 forever!"

 

Maybe just a leaking exhaust gasket at the cylinder head?
Palle.

 

wrote:
"Every 4 rev.s" or every 4 pulses?


I have no idea what I was thinking when I wrote that, from what I can
remember it was about once a second or so at idle.

So it may be a lash adjuster. I have the repair manual for the bike
which I'll have to refer to but I'll have to take the head off the
engine in order to get at these I would imagine. I'll have to check
those the next day or night I have off.

Matt

 

I should have mentioned this before I guess, better late than never.

The bike runs and starts perfectly fine despite the ticking noise.

Matt

 

hmmmmmm.... a leaking exhaust gasket

Well I removed the exhaust system today actually and one of the
gaskets did look a little rough. I was also going to replace those. I
don't believe that it could have been the gasket though, the sound
seemed to be coming from the #2 cylinder when I did the good old ear
to screwdriver to sound test. Although I guess it is a possibility.
This is the very first motorcycle engine I've worked on after all.
I've done all kinds of work on Z24s and some on a '83 GT Mustang (if
you ever have a problem with Z's chances are I've fixed it). I have
come to realize that motorcycles are much less like car then I first
thought.

Ok so those hydraulic lifters aren't really lifters at all beacause
they do not move. The only thing I can't wrap my head around is if
they don't move how can they be the cause of the problem? I'm not
saying you're wrong I agree with you that one of the lash adjusters is
gone. It's just that I have no idea how they work. The manual does try
to describe how but does a very poor job, like they tried to make it
too simple to understand and never went into enough detail. If anyone
can explain exactly how they work and why the do not work correctly
when air manages to get inside it'd make fixing or at least
understanding the problem easier. (hint hint wink wink)

Anyways I already have all the lash adjusters and cams removed from
the bike and placed in a tackle box (yes a tackle box) exactly the way
they came out of the bike. There is a test in the manual to show if
one of them is gone or not. I believe it involes pressing a 1/16th
drill bit into the hole in the top (with the chuck end) down with a
wood block and seeing if it move 0.2 mm or something insanely
difficult to measure like that. My father could probably bring an
digital (ummm... geez insert correct word here not a caliper I don't
think) home with him from work, but I guess if the adjuster is gone
bad enough (which I have a sneaky suspicion that it is) I'll probably
be able to see or feel it move. I'll have to try that tomorrow.

Sorry about the long posts but I really want to get has much info has
I know here so that I'm not misunderstood, and so that the culumitve
knowledge of rec.motorcycles.tech can fully understand what my trouble
is and correctly asses the problem. Again thanks to everyone who has
already posted, your input has been very helpful. Also thanks in
advance to anyone else who can help.

Matt

 

Yes that does help.

Ok now I think I understand what happened here. The first thing I did
after I bought the bike and brought it home was that I changed the oil
and the filter. One kinda odd thing I noticed about the old filter was
that the internals were let go. Then when I took the valve cover off I
did notice at least one small piece of metal (if not two, I can't
remember now it was so long ago). So I guess this guy didn't believe
in changing the oil filter and some foriegn material (ie chunks of
metal) got into the tappet or the oil feeder hole for that tappet and
resticted the flow of oil.

So if that piece of metal is still there how in the #$%# am I going to
get it out. I thought I was being quite intelligent and tried a magnet
but of course almost everything is aluminum (d'oh), so obviously
thats not going to work. I did try it anyways to see if it would pick
up anything from the cams etc. but I came up with nothing in all the
lifter (yes I'm going to call them lifters) holes and the oil
passageways. So if there is anything there it is either stuck or
aluminum as I was using a rather strong magnet.

If there is a piece in one of the lifters is it possible to get it
out? Will bleeding them alone get out any unwanted material (the
manual says to use kerosene). I don't think I'd have any way of
knowing if there is anything in there anyway. So if it is highly
unlikely that I can remove the material from the lifter I need to know
where I can get at least one if I start the bike and the tick is still
present. I did try to order one at my local Honda dealer but of course
it would have been a back order. Does anyone know where they are
readily available?

Thanks again for all the help,
I'd be completely lost only for you guys.

Matt

 

The way parts stocks are these days, the only way you're going to find
one 'in stock' is if some junk/breaters yard has an engine, or an
enthusiast/specialist (i.e. someone who knows what it's worth) has a
supply of New Old Stock parts.

I can't think of any other way to get the parts, honestly.

 

Ok, I'm going to call my not so local motorcycle scrap yard on Monday.
I seriously doubt that they have a CB550SC there. But if they don't
I'm thinking I should be able to get lifters out of a CB650SC since
they share alot of thier parts. I am under the impression that the
engines are very similiar. The manual I have lists only 1 procedure
for the engine related work I have looked at. Does anyone know if my
preconceptions are correct or if they are just that (preconceptions I
mean)?

Anyways I will post again on Monday after I speak with the guy at the
junkyard and let everyone know what I found.

Thanks again all.

Matt