Topic: So... this is bad, right? *Update on post #9*

[Dimitri13]

So the other day, I (believe I) spun a bearing. Engine still turns over and even ran, but had one helluva knock/click/tapping noise. Needless to say I didn't run it for too long. I had stopped to make sure there was enough oil in it (even though I knew there was because I just changed the oil and verified there was enough before taking off), a bunch of smoke came out of the filler hole.

I finally got outside to assess the situation. Drained the oil, and just as I thought, glitter.



Started tearing into the engine. First removed the breather cover, and verified the hose and tube wasn't blocked. Next came the tappet covers. All the adjusters looked to be fine.

Next came the valve cover. To my surprise, there was very little oil in the cam area. It looked as if my fresh oil had gotten in there at some point, but didn't stay there. Needless to say, the cam and rockers looked burnt up.



(same lobe, different angle)




(same rockers, different angle)


I didn't remove the cam yet, but the cam surface on the valve cover looks okay.

Are these damaged beyond reasonable repair?

[lucky]

So the other day, I (believe I) spun a bearing. Engine still turns over and even ran, but had one helluva knock/click/tapping noise. Needless to say I didn't run it for too long. I had stopped to make sure there was enough oil in it (even though I knew there was because I just changed the oil and verified there was enough before taking off), a bunch of smoke came out of the filler hole.

I finally got outside to assess the situation. Drained the oil, and just as I thought, glitter.



Started tearing into the engine. First removed the breather cover, and verified the hose and tube wasn't blocked. Next came the tappet covers. All the adjusters looked to be fine.

Next came the valve cover. To my surprise, there was very little oil in the cam area. It looked as if my fresh oil had gotten in there at some point, but didn't stay there. Needless to say, the cam and rockers looked burnt up.



(same lobe, different angle)




(same rockers, different angle)


I didn't remove the cam yet, but the cam surface on the valve cover looks okay.

Are these damaged beyond reasonable repair?

The rocker arms look ok.
I do not see anything serious.
&50 or 550?
How many miles are on it??

QUOTE" I believe I spun a bearing??"  How can you tell such a thing?
Experts cannot tell unless they take it all apart and look at all the bearings.

[Flying J]

yeah those look normal/good compared to some of the rocker arms i have. You could always try and drop the oil pan and see if you can see anything. Maybe your primary is rubbing... Dont know but dropping the pan is an easy thing to do before you have to start tearing things apart to find the problem.

[Dimitri13]

Well, something is definitely wrong, because those rockers didn't look like that last time I had the valve cover off.

That's a good idea dropping the oil pan. I would've continued tearing the engine apart and not even doing that

Although I likely will be doing a rebuild anyway.

[dave500]

maybe remove the alternator cover,,perhaps the rotor has come loose??check the clutch circlip hasnt dislodged aswell??might save a total tear down?

[Dimitri13]

Well, I'll be doing a total teardown for polishing/painting/rebuild anyway, but I'll make sure to check those thoroughly.

[dave500]

ok if your tearing it down anyway youll get to the bottom of it,,dont forget the pictures!!that top end wouldnt be making all that noise.

[Dimitri13]

Yeah, that's why I think I spun a bearing. It does look like the top end got starved of oil somehow. The rockers and cam look scorched, and there was a severe lack of oil when took the valve cover off. usually there's pools of oil underneath the cam, but it was nearly dry. So I'm thinking the top end overheated, and stuck a piston just long enough to spin a bearing, but not completely seize the engine.

Well, that's my theory at least. When I get to the bottom I'll find out for sure.

[dave500]

with a running engine the piston isnt going to stick without the engine slowing down and stopping,,it wont stick for a micro second,,lets see what you find,with the valve cover off crank the engine with ignition off,,you should see oil come from each end of the cam journals,,you might have a blocked oil restriction if it dosent flow on one side.

[Dimitri13]

Alright so I tore the engine down more. I've removed the jugs. Rotating the rods on the crank, they all seem free, so I may be in the clear on the spun bearing idea. While tearing down more though, I think I may have bent the cam chain tensioner?



Then I dropped the oil pan and found basically metal sand (the big, gritty hawaiian sand)



I checked out the primary chain, I didn't see any evidence of it grinding into the oil passage, but it is LOOSE. I'm talking Paris Hilton loose.

[dave500]

some one might have bent that getting it in last time?pull the primary chain down and see if it can touch the case?

[Flying J]

Are the shavings aluminum? or steel? looks like aluminum.

[RAFster122s]

They slap around a lot when loose... cam chain can groove the passage through the cylinders wider, primary chain can cut into the cases in various areas.  Read the cb550/cb650 hybrid thread that Paulages put together. He installed the cb650 primary chain tensioner in the cb550 cases. Very slick solution.  How many miles on your motor?

[Dimitri13]

Dave, I had one helluva time getting it out and I believe I was the one that bent it (I bent the top a bit too pulling on it, but was able to bend it back). Is the bottom fixable? If so, have an example of how it should look? I'll be splitting the cases tomorrow so I'll see if it contacted anything.

ff, they appear to be aluminum.

RAF, I'll look into it. There was about 26k on the engine. About 17k from the first owner, and 3k from the previous owner (who severely neglected it), then the rest from me, and I ride hard.

[dave500]

dont try and remove that tensioner without lifting the barrel with it,you have to install it into the barrel then drop the barrel on the case aswell,,this is where the bottom can get mis cued and foul on the primary hub,your doing a good job,clean all the parts as you go,post some all angle photos of the tensioner,you should be able to gently bend it back,show us the face of the blade,they can be replaced,,the whole assembly is expensive as a unit,,i dont think the 500/550 cam chains can foul the case tunnel as much as the 750s can?ive had some pretty thrashed out engines and none have had cam chain tunnels worn?

[Dimitri13]

Damn, really? My manuals didn't say anything about lifting the jugs with the tensioner, just remove the head, remove the locknut, and lift :/ When I get out there tomorrow to split the cases I'll get a picture of the blade. Should I also get a picture of the guide? The guide has a groove worn into it, but it's not that deep.

When bending it back, judging by pics on ebay, I should be bending just below the tensioner bolt where the sides look "flared out?"

[RAFster122s]

Dave500, yeah I read 750 and 550 threads and have seen grooved case tunnels but didn't pay attention that it was a 750 issue. I haven't seen it on mine.  Read on some thread here that the 500/550 can need primary chains as early as 30-35k miles. Worries me some as mine has 31k...but no noises to be worrisome yet.

David

[Dimitri13]

I knew I needed a new primary chain because slop and lugging from a dead stop. I had planned on a full rebuild once I was employed again, and didn't think it'd be an issue waiting til then. Obviously I was wrong ~_~

[RAFster122s]

Dimitri, I understand where you are coming from. I just got laid off myself. Took me 2 years to find a job the last time I was out of work. I really am not looking forward to anything ressembling the last time... Guess it might be time for going back to college.
Hawaii is an expensive place to live.

Good luck in your search and hope the rebuild isn't too pricey!  When we have the time we don't have money and sometimes the lack of employment and search makes it hard to be motivated to do anything.

[fastbroshi]

Damn, really? My manuals didn't say anything about lifting the jugs with the tensioner, just remove the head, remove the locknut, and lift :/

Whenever I'm tackling something paricularly complex or new I usually try to refer to my Clymer's and the Honda manual to make sure nothing's been left out of either source.

[dave500]

i just had a quick look at the honda workshop manual,at fig63 the caption states to lift the barrel 20mm to facilitate tensioner removal,i normally wiggle it up untill i can remove it,ive never seen that either untill now!

[Dimitri13]

Hm... I had my honda workshop manual open, but I don't think I looked at it for this particular step, just my clymers -.-

[dave500]

i only have the downloaded 500 one which also has the 550 supplement?

[Dimitri13]

I downloaded whichever workshop manual is in the stickied manual thread.

[lucky]

Yeah, that's why I think I spun a bearing. It does look like the top end got starved of oil somehow. The rockers and cam look scorched, and there was a severe lack of oil when took the valve cover off. usually there's pools of oil underneath the cam, but it was nearly dry. So I'm thinking the top end overheated, and stuck a piston just long enough to spin a bearing, but not completely seize the engine.

Well, that's my theory at least. When I get to the bottom I'll find out for sure.

Just take it apart and you will find out.
Why even get everyone to tell you what they think is wrong when no one can say?
We cannot hear it ,we do not know its history- nothing.

[Dimitri13]

Split the cases finally. Took forever (who knew you had to remove the pistons to get the top case off? selective reading, of course). It was dark already so I wasn't able to look at everything, but a quick glance revealed the primary chain has about 1/2" of slack, and one of the con rods has a ton of free play on the crank. I couldn't see anywhere where the primary or cam chain ate into the case (will be 100% sure tomorrow), so is it possible the amount of shavings in the oil pan is from the bearing getting gradually chewed up? What are the bearings even made out of?

Thanks for all the help so far guys. Will post more pictures tomorrow as well.

[fastbroshi]

That doesn't sound good.  Definitely warrants more inspection.

[trueblue]

The bearings are made of white metal on a steel backing, I'm not sure exactly the metal composition of the bearings, I think they are an aluminium alloy of some sort.  It looks like bearing material in the picture of your sump.  If you spin a bearing it doesn't take long to chew it to pieces and makes horrible noises, sort of like someone hitting on the inside of your engine with a large hammer.  Also if you can feel movement in any of the rod bearings the bearing is shagged.

[Dimitri13]

Oh, and one of the intake valves is stuck in the guide. It looks like the top got hit and has spread out just a bit, making a lip that won't go past the top of the guide.

Is it okay to sand off the lip to get it out?

What do I use to clean off the carbon from the chamber, piston tops, and valves?

[trueblue]

Oh, and one of the intake valves is stuck in the guide. It looks like the top got hit and has spread out just a bit, making a lip that won't go past the top of the guide.

Is it okay to sand off the lip to get it out?

What do I use to clean off the carbon from the chamber, piston tops, and valves?

Use a small file to remove the burr and a wire buff to clean the carbon off.

[Dimitri13]

A wire buff... Like a wire wheel? Can I just take it to my bench grinder?

[trueblue]

Yeah a wire wheel, you can use one attached to a bench grinder, but it is not the best for the head, it is a bit rough on the aluminium.  You are better off using one attached to a drill or die grinder to clean the chambers.

[Dimitri13]

Alright. I have a wire brush attachment for my drill. Valves and pistons on the bench grinder are fine?

[trueblue]

Valves are fine on the bench grinder with a wire wheel, pistons are ok, just be very gentle with them and take your time.

[Dimitri13]

Will do.

[CBGhia]

If you have a brass wheel, I would use that.