Topic: Dead Horse Topic #4532 - ticking top end

[RainyRider]

OK here's the deal:

Carbs good, sync'ed
Valves adjusted
Timing set, points gapped
new plug caps
new plugs
compression good
oil changed

Ticking persists, seems like it's not running on all 4. Could be plug wire, what is the measurement again? Measure from wire 2 to wire 3 and get like 10ohms? or was it wire to ground?

Could be something in the valve tappets, bad rocker shaft/pin? I need to take the cover off again to retorque the head anyway, maybe I'll wiggle them. I imagine there should be no wiggle on those rocker shafts. Any hints here?

Also - got a lead on a parts bike I may be picking up in the next couple of days. I'll try the coils off this one. Maybe it has a good head or other...

~RR

[SOHC4ever]

I certainly admire your tenacity, Rainy. Just remember: You LOVE wrenching old bikes. Yes you do. Say it like a mantra.
I'm in Vancouver, BC, and have a bona fide medical stethoscope that you can use if you like. Maybe we can meet half way. If not, give the screwdriver or hose method a try. That's undoubtedly your best bet on localizing the noise.

DON'T GIVE UP.

[tlbranth]

Actually Rainy, I'm just east of Seattle. If you'd like a second ear on it, I'd be happy to loan what's left of my hearing. I'm here most of the time.

[RainyRider]

Actually Rainy, I'm just east of Seattle. If you'd like a second ear on it, I'd be happy to loan what's left of my hearing. I'm here most of the time.

I'm just up in Silver Firs, this would give me another reason (like I need one) to take the High Bridge Road. I would LOVE a second opinion. I've done the screwdriver thing, I've pulled off tappet covers. It sounds to me like it is coming from the cam chain.

Could somebody please list the symptoms of a worn cam chain? could it cause uneven running - enough to make a single cylinder too rich?

Anyway tlbranth, I'd really like to give you the opportunity to hear this beast, I'll sen you a PM.

Thanks!

[SOHC4ever]

It sounds to me like it is coming from the cam chain.

Could somebody please list the symptoms of a worn cam chain? could it cause uneven running - enough to make a single cylinder too rich?

I forgot: did you rebuild the cam-chain tensioner mechanism? Don't know about 550, but it's super easy on the 750. That quieted my cam chain down pretty good.

[RainyRider]

It sounds to me like it is coming from the cam chain.

Could somebody please list the symptoms of a worn cam chain? could it cause uneven running - enough to make a single cylinder too rich?

I forgot: did you rebuild the cam-chain tensioner mechanism? Don't know about 550, but it's super easy on the 750. That quieted my cam chain down pretty good.

I did pull the head and put in a tensioner and guide (that I bought off eBay). The tensioner I installed was in good working condition but not new. See earlier posts in this thread for a pic of the totally broken cam chain guide that I replaced. I thought that would solve the noise, but no dice.

[RainyRider]

For anyone still interested in my persistent ticking problem:

Well, forum member tlbranth loaned his ear and sacrificed his oil-catching flattened cardboard box, along with 1/2qt of oil, to help me check out the problem. The ticking really sounded strong (using screwdriver stethoscope) behind the alternator cover. Not having the Clymer manual handy, we pulled that cover off and ran the engine. about 10 revolutions into this test, the oil plug popped out and we dumped 1/2qt of oil out of the bike. We then held the plug IN and ran the bike, ticking still there. Query: The sound is getting over to that alternator cover in a strong way, what could be doing this? The crankshaft?

More info - with a recent timing adjustment, the sound has diminished again. I found out (should have read TT's posts over and over again until I could recite them verbatim) that the points plate moves just a hair when you crank down the screws after adjusting the gaps and timing, you need it held firmly in place during the adjustment and while tightening things back up. I am now confident that my timing is about as good as it gets. Bottom line - TIMING (difference between 1,4 and 2,3) AFFECTS THIS TICKING SOUND.

Clues so far:
1. TICKING SOUND IS STRONG AT THE ALTERNATOR COVER
2. TIMING ADJUSTMENTS AFFECT THE INTENSITY OF THE TICKING

Next - we noticed that while bike was sitting, it would periodically (every 3 minutes or so) dump a few teaspoons of gas out the #3 carb overflow tube - I had left the petcock ON. Reading previous posts in the thread would show that #3 seems to be running quite rich, carbon building up on the plug. Gas dumping out of the overflow indicates sticky or improperly set float heights. Now I'll fix that problem - I thought I did this correctly before but apparently not. Could uneven running be due to very rich cylinder #3? Seems so...Could very rich #3 be caused by improperly set floats? THE FORUM SEZ YES.

CLUE 3. STICKY OR TOO SMALL FLOAT ADJUSTMENT CARB #3 - increase to proper setting to test this.

NAIVE INFERENCES:
1. Bike is running unevenly due to one carb being too rich due to bad float adjustment or sticky float.
2. Uneven running accentuates SLACK IN THE CAM CHAIN that I didn't replace when I had the head off (I suck).
3. Worn-out cam chain is smacking around - or is slacking/tightening/slacking/tightening in time with the uneven running caused by the carb problem - creating a prominent ticking that makes itself most evident in the middle-lower case - clearly audible on the alternator cover.

FAKE PROOFS that make me want to believe my inferences:
1. Timing between 1,4 and 2,3 changes the ticking - another cause of uneven running
2. The cam chain guide and adjuster were shot for a while (years?) before I got in there and changed them with replacement worn-out parts
3. This wore the cam chain out, or wore the lower cam chain sprocket?!!!!!?!??!??!! making it difficult to tension properly, I probably should get a NEW tensioner in there and replace the chain.

ACTIONS:
1. Fix carb #3 and run for a while.
2. Exchange plug wires 2,3 and run for a while to rule out plug wire/coil issue - weak spark causes carbon and uneven running too...
3. Rip 'er apart and finally replace that cam chain. I have the tools, I have the chain. Just do it.
4. After all this work, ride it until the noise comes back.

[Simpson]

Kudos my man, you have done an excellent job investigating your issue. At this point, with all the energy you have put into the bike, you can't stop until it's fixed. Today is the first time reviewing, otherwise I would have posted my thoughts earlier. From the first page of this thread I diagnosed the symptoms a little differently than others who have posted. Mainly because I've had a similar experience. All clues point to what's called a galded/galded cylinder. This is when a engine over heats from maybe improper lubrication and the piston material welds to the cylinder. The imperfection in the cylinder wall will create ticking harmonics. Sounds much like a tappet valve out of adjustment. You can try to tune it out but it never completely goes away. It only taunts you by becoming quiet and then getting louder again.

Symptoms: Ticking, possible small loss of compression, perhaps small mount of oil burning

All depends on the severity of course.

If this is the case you can live with it until engine do you part or replace the cylinder, piston and rings.

In my case I replaced the entire engine because CB360 engines are so cheap. 50 clams.  

Good luck, and don't give up!

PS I didn't get a chance to listen to your video, I'll review it tonight.

[RainyRider]

This is when a engine over heats from maybe improper lubrication and the piston material welds to the cylinder. The imperfection in the cylinder wall will create ticking harmonics. Sounds much like a tappet valve out of adjustment. You can try to tune it out but it never completely goes away. It only taunts you by becoming quiet and then getting louder again.

This is quite possible - when I bought the bike in October last year, the PO rode it daily but neglected to do maintenance. My first oil change (50mi after I got it) the oil was BLACK and NOT GOOD. I ran Marvel Mystery in the oil for about 2000-300 miles then changed it again. Since then I've put 1800miles on it, changed oil again 300mi ago, and it hardly got discolored at all for those 1500mi.

The bike leaked oil a bit and the PO never changed it, but added when necessary, and I assume he missed several times when it was too low.

Anyway, thanks for the new info...

~RR

[RainyRider]

Bu-bu-bu-BUMPITTY BUMP!!

New Information - I was changing the oil, and pulling the oil pan off for the first time (I've owned the bike for about 2200 miles). There was a decent amount of sediment (a couple milimeters thick in the grooves), some little metal pieces (not much, very tiny, like flakes), and some plastic pieces left over from the shattered front cam chain guide (see previous entry in this discussion). After cleaning the pan, I decided to look up inside there, to see what I could see...



Yep - the cam chain tensioner is not seated into it's little place at the bottom of the engine, and is rubbing against what I think is the starter clutch? (what is that?)

I'll be taking the top end off (again) to replace the tensioner (again) - I happen to have an even better one off a parts bike I got. This may have something to do with my noise, but probably not, given my luck.

[bryanj]

That adjuster is very close to the primary cahin and could well be your ticking noise

[RainyRider]

That adjuster is very close to the primary cahin and could well be your ticking noise

That's what I'm hoping...

[tlbranth]

Rainy, sorry you're still having trouble. But since the 10-month 'rainy season' is upon us, you'll at least have time to muck with it.

[RainyRider]

BUMP for BUMP's sake.

So, also while I had the pan off last fall I noticed the primary chain was quite loose. And the bottom of he case was a bit roughed up. I did some reading and decided that my primary chain was too loose. A local mechanic had a spare engine with 6k miles on it, and the primary chain was tight. Long story short: new engine, no ticking. Case closed.

Now to fix my wheel problems...