HORRIBLE NOISE

[joedrum]

that happens ...it happen here before with jungo bike

 

[Steve83]

Well, the fact that it's still running is a good sign. If it is something in there, hopefully it's something small that does no serious damage. I bought a 1980 1100 with 4 bent valves, caused by a stripped timing belt, and there was no piston damage, just very small indentations where the valves were hit. These are very tough engines!

 

[Write2Paul90277]

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Let's hope so!

I'm not gonna sit around and wait for Amazon to send my borescope -- I'm pulling the cylinder head today.

Will report back when there's something to report back.

Thanks,

Paul

 

[dan filipi]

I don't see any reason to pull the head (yet). I'd pull the valve covers and feel the rockers for excessive play then make a decision based on that.
180-185 reads I would question the gauge or cranking speed for 160. The 160 read could possibly be caused by the adjuster having leaked down while cranking to test (the other cylinders).
The noise is way too sequential by my ears to be something that dropped inside.

 

[Write2Paul90277]

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Thanks Dan,

Yes, I have pulled the valve cover (on the noisy side) and I don't see or feel anything obvious. Next step would be to remove and inspect the rocker arm/cam assembly. To do that I need to remove the timing belt and cam pulley. At that time I'll scrutinize the cam, springs, valve keepers, rockers... and those wonderful hydraulic things that you have to submerge in kerosine in order to test and fill.

Depending on what I find (or don't), I may go deeper. :fishin:

What fun!

Paul
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[dan filipi]

They say to keep the adjusters upright so they don't drain out, and if they do you have to refill them. I never paid any attention to all that. Put them in, start it, and let the oil system do its job.

 

[Tom_Charlton]

dan filipi » Sat Nov 05, 2016 3:48 pm[/url]":3kfmymn8]
They say to keep the adjusters upright so they don't drain out, and if they do you have to refill them. I never paid any attention to all that. Put them in, start it, and let the oil system do its job.

Leave the kill switch off and crank until the oil light goes out. You now have pressure for the adjusters and can safely start the engine.

 

[slabghost]

it'd be a good idea to leave the fuel shut off too during this procedure.

 

[dan filipi]

Curious what you find. What's the latest?

I don't think has been mentioned there is a filter screen on top of the cam holder. Could have some junk in it blocking oil to the cam and tappet adjusters.

 

[Write2Paul90277]

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Thanks Dan, I'll have a look. I disassembled the right side cylinder head and haven't found any problem so far. All the springs are intact and measure out to spec, no clogged oil passages, broken rocker arms, cam lobes etc. I will check the filter screen as you suggest and bleed any air out of the hydraulic adjusters while I'm at it.

As long as I have one head off, I'm going to pull the other one and examine. If I find nothing there, I will have to assume that the horrible clacking sound is deeper inside, (piston slap or piston skirt hitting the crank due to bent [hydrolocked] connecting rod?).

I REALLY don't want to have to remove the engine and split the cases!!!


Paul
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[slabghost]

1200 is pretty stout motor. I really doubt there is anything wrong with the bottom end.

 

[Write2Paul90277]

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We shall see!

I'll report back tonight or tomorrow.

Thanks everyone for your help so far!

Paul
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[joedrum]

once you get the heads off ...you can turn the motor by hand and see how the pistons top out ..a bent rod or play in piston turn around before going back down can indicate problem in lower end ...you can useally feel this stuff with a light touch on the piston ...im betting its ok ...as said 1200s are stout

 

[Donpauli2]

Bottom end problems are highly unlikely unless oil flow is cut off. A boxer style engine has a virtually indestructible lower end because all forces of rotary motion are held by another solid side supporting the mains unlike a conventional engine where the energy is held by bearing caps and bolts


Sent from my iPhone using Tapatalk

 

[Steve83]

With the heads off, turn the engine until each piston is at top dead center. If you have a bent rod, its piston won't come all the way up. With the pistons at mid-travel, turn the engine slightly back and forth while touching each piston. If a rod bearing is badly worn, you will feel the play.

Did you disassemble the cam holder/rocker shafts/hydraulic adjuster assembly?

 

[Write2Paul90277]

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UPDATE:
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Hi folks,

Per joedrum's and Steve83's suggestions, I removed both cylinder heads and rotated the crank to confirm that all four pistons were indeed reaching TDC (hallelujah, no bent rods!). I also checked the pistons at mid-travel and didn't detect any excess play that might indicate overly-worn rod bearings.

So far, so good -- that horrible clacking sound does not seem to be coming from the bottom end!

Next I turned my attention to the cam holder/rocker shafts/hydraulic adjuster assemblies. There are no bent valves or broken spring. Everything measures within the normal service range. Also, all the oil lines appear free-flowing with no clogged passages. So, what could the clattery noise be?

When checking the hydraulic adjusters, I did discover air trapped in a couple of them, which could have been causing the noise. I bled them according to the manual. I also filled the de-foaming chambers and measured the exhaust rocker arm shaft center collar clearance, which the factory says can be a source of clicking/tapping noise.

Currently I have one head back on the bike and will install the other one in a day or two.

Fingers crossed that this solves the problem. Whether or not it works, you guys will be the first to know.

Thanks,

Paul
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[dan filipi]

If it helps any....I ran mine the other day on the side stand at a fast idle to warm up. After a couple minutes I started getting a very loud tappet which remained until I reved and held it at a higher rpm for 5-10 seconds then it quieted down. It had been sitting at least a month since the last time I ran it. Tapping didn't come back the rest of time running at idle thru a fan cycle then shutdown.

I think it's very possible air can get into the hydro adjusters and will bleed out with running.

 

[mcgovern61]

opcorn:

 

[Steve83]

Hoping for the best outcome!

 

[Ansimp]

Steve83 » Wed Nov 16, 2016 3:54 pm[/url]":29yayjsf]
Hoping for the best outcome!

+1 :yes: