Engine knocking need help identifing

[dan filipi]

The valve springs are a weak link on these engines.
The bottom end, pistons, rings and cylinders are damn near bullit proof.

I would go so far as to pull all the valve springs with the head in place to check them before even pulling the head.
We have tricks for doing this making it much easier than pulling the head.

If we weren't so far apart id run over this weekend for a live listen.

 

[Jalvarez]

Dan: I'd hate to split the case only to find nothing is wrong. Whcih was to reason for this thread. I truely hope that you have a brain storm tonight or tommorrow in the middle of the night. As far as the trans. I already went through all the gears and everything checked out when shifting. noise still the same with no change. Remember that this is the second head and with different rockers and the noise still there.

Mcgovern61: Both tentioners spinning smoothly and appear in good condition. If they were bad would they screech, wooble or whine if they were bad. How else can I check them?
all springs were checked by machine shop to be in spec not loose, or weak. Unless they missed one?????

At this point I am still at a loss and confused. Why would the nosie continue with the rockers removed from pistons 2 & 4. This again indicates it is not a valve, rocker and or cam issue.

 

[scdmarx]

I dunno, it just really "sounds" top end to me. But I'm not there. :head bang:

 

[joedrum]

yes im sorry to say that its getting clear its lower end noise ...if your going to take it out of the frame ...id first strip the heads off first ...then spin that baby with the starter if its lower end it sould make some noise then and wont be cancelled out by air coming out of plug hole ...at least this way there might be total conformation on it .....keep at it i admire your drive to fix it ....and one way or the other your going to get it im sure ..gee i just read rons post and hes thinking top end hmmm his voice is mighty so are the others mines absent from listening to it ...well im going to post anyway on maybe stripping the heads for a final test :crying: darn bike

 

[slabghost]

By any chance do you have another cam for that side? If so have you tried it or is this the same cam throughout all your testing? Have you inspected the cam lobes and bearing surfaces? All look polished or evidence of flat spots or galling?

 

[esker]

It sure is a baffeling mystery to what could be causing that tapping sound. Re-reading all your posts it looks like you have done quite a bit of testing to show that the heads seem to be fine and not causing that taping. I have been listening to the tap tap tap so much and then I got to counting them and it seems that you get roughly around 425 taps more ore less per minute. Your tach reads around under 900 and is really difficult to tell exactly what the crank speed is. But with the 425 taps per minute, it seems, to my way of thinking, that the tapping is related to the cam rotation speed. In your post #58, I watched and listened to your Youtube video and near the end you blipped the throttle two times. From what I was hearing, it sounded something like a ratcheting sound and interestingly enough, after the second blip of the throttle, the engine speed was quickly decreasing but that ratcheting sound continued on for another second or so. It was something like holding the socket on a socket wrench and giving the handle a spin. What would it be? A bearing spinning or a chain on a sprocket perhaps. It strange that noise goes away at a lower idle or when the spark plug wire on #2 piston is removed.
So if the cams rotate at 425 rpm, would the crank not rotate at 850 rpm and any problem in that area be heard 850 times a minute?
Just some more thought thrown into the mix.

 

[joedrum]

this thread is going to motivate me to fix my wires on the speakers on the computer

 

[mcgovern61]

this thread is going to motivate me to fix my wires on the speakers on the computer

:smilie_happy: :smilie_happy: Hurry up Joe!! :smilie_happy: :smilie_happy: I will hum a few bars while you are working on it! :smilie_happy: :smilie_happy:

 

[mcgovern61]

Remember that this is the second head and with different rockers and the noise still there.

Good point! Assuming different springs meaning the springs that came with the different head?

Mcgovern61: Both tentioners spinning smoothly and appear in good condition. If they were bad would they screech, wooble or whine if they were bad. How else can I check them?

No...that is all you can do with them, it was just a check to help narrow down and eliminate all simple sources of noise.

all springs were checked by machine shop to be in spec not loose, or weak. Unless they missed one?????

I suppose it is possible? The fact that the tapping happens even with the rockers off could still point to a weak spring - vacuum in the cylinder pulling the valve in and snapping it back?? (I know...really out there :roll: )

At this point I am still at a loss and confused. Why would the nosie continue with the rockers removed from pistons 2 & 4. This again indicates it is not a valve, rocker and or cam issue.

Can't argue with this point, but not willing to give up on weak springs yet! Anything else starts getting bigger and harder to repair!

Out of curiosity, did you ever have this engine running without the tapping noise? What is the history of the bike (if you know?).

 

[Jalvarez]

Joedrum: If I strip the heads & spin the motor I don't expect to hear the noise as it only happens with the motor running. But if I do pull the motor I will do that. Thanks

Gerry: Yes the engine running without the tapping noise. I was on a simple short drive when the tapping started and quickly worsened. That was the reason I pulled the heads to begin with….. thinking it was head, valve related.

Slabqhost: I do you have another cam for that side and yes it has been the same cam throughout all testing. All looked polished with no evidence of flat spots or galling. I assume the machine shop would have checked it all out. At least he said he did.

To all: After reading all your suggestions and recommendations (which I appreciate very much) I am going to change to another cam from another recently refurbished head. If that doesn’t correct the problem I intend to replace the valve springs on piston #2 too see if that does it. If both those changes don't work I intend on replacing the head once more time before reluctantly pulling the engine.

Any further suggestions before I take these measures................. would be greatly appreciated

 

[mcgovern61]

Yes the engine running without the tapping noise. I was on a simple short drive when the tapping started and quickly worsened. That was the reason I pulled the heads to begin with….. thinking it was head, valve related.

Hmmmmm.....that kind of indicates something came loose! To my knowledge, bottom end failures of bearings and such are much more gradual? (Unless it is run without oil like my '82 was.....snapped stuff right off :roll: )

 

[mcgovern61]

BTW Dan.....doesn't Jalvarez qualify for the Knockers club?

 

[Jalvarez]

To all: I don't recall if anyone has any thoughts on the starter chain. Is it worth removing the starter to check?
The reason I ask is eskers comments

 

[joedrum]

there is nothing you can do to fix anything about the starter chain by taking the starter out...if it was something there its still an engine out deal to fix ....the motors are not that bad to take out ....i was thinking the sound was more in the frint of the motor ....you seem to be quite able in working on things ...the starter chain is awlful to the sator bolt have you checked that !!!! they have mimiced bad motor sounds in oldwings and it happens enough to be common thing ...screw that cap plug off the back of the sator and tighten it ...let me know for sure you done this

 

[Jalvarez]

Joedrum: I have been using that bolt to turn the engine to the timing marks. If I am in the right area

 

[joedrum]

if you take heads off while motor is still in the bike and turn the motor over by hand with plugs out you can watch the hesitation at the top of the stoke on the cylinders and see if one hesitates longer than the others ....this can be a sign of bad rod bearing or piston pin ....just a thought

 

[dan filipi]

BTW Dan.....doesn't Jalvarez qualify for the Knockers club?

Most definately yes!

 

[Jalvarez]

if you take heads off while motor is still in the bike and turn the motor over by hand with plugs out you can watch the hesitation at the top of the stoke on the cylinders and see if one hesitates longer than the others ....this can be a sign of bad rod bearing or piston pin ....just a thought

Thanks for the tip Joe

 

[Jalvarez]

BTW Dan.....doesn't Jalvarez qualify for the Knockers club?

Most definately yes!

What is trhe knockwers club?

 

[dan filipi]

BTW Dan.....doesn't Jalvarez qualify for the Knockers club?

Most definately yes!

What is trhe knockwers club?

The Knockers Club we started a while back after trying to find a knock in my 83 1100.
It sounds different then yours but we had read there are others with the same or similar knock and other "strange knocking" noises from these engines.
So congrats, you are now part of this elite club!
Not sure it's anything to be proud of but what the heck.