knock 3 times.....

[Anonymous]

ok, here goes...

bike is an 82 gs1100g with about 35k miles on the clock

after the bike is running and the choke is off, I hear this knocking/rapping noise. The strange part about the sound is that it's not constant--there a 3 (sometimes sounds like 4) knocks, then about 2 seconds later, it repeats itself...something like---knock knock knock, wait, wait wait wait wait, knock knock knock....and so on...

i thought that maybe the sound was the cam chain slapping, but i took the tensioner apart and everything looked ok...

it's also a bit hard to tell exactly where the sound is coming from, which is typical...

i know, i know, diagnosing something like this without actually hearing the noise is nearly impossible, but what else can I do?

any ideas on where to look at?

thanks

Brian

[argonsagas]

Let's see....."Knock three times....."

Do you ever get "twice on the pipes"? :roll:



Don't know the answer to this one, but I would suggest a stethoscope to help identify the source of the noise.

If one is not available (this is actually the second time this week I said this 8O ) try holding the end of a broom handle against your ear and the other end against the engine.

Move it around the engine until you identify where the noise is most prominent.

[Anonymous]

GREMLINS!

DAMN GREMLINS! I got one in my carb right now. I hope you find yours.

[focus frenzy]

does it only do it when warmed up, in neutral, with the clutch released?
how about with the clutch engaged, and in gear with the clutch engaged, and riding?

[Anonymous]

clutch in, clutch out, in gear or not, doesn't matter. Rev up the engine, and the knocking does the same, it's just a bit harder to hear. Ever since this noise has come to my attention, I haven't ridden the bike to get it warmed up, to see if it goes away--don't wanna do more harm.
Regarding the stethoscope, that's on my "new tool list" for this weekend.

thanks for the replies so far......

[SqDancerLynn1]

Check to see if the stator magnet has come loose on the crankshaft ????

[Anonymous]

".... on the ceiling if you want me". I can't believe I'm old enough to know that damn song. *shudder*

[Anonymous]

Knock Three Times

I love Tony Orlando and Dawn!!!

[Einar J Skog]

May be it is cam end float ???
On my mc it is noisy with warm engine (waiting at red light)a little irritating.

[Anonymous]

May be it is cam end float ???
On my mc it is noisy with warm engine (waiting at red light)a little irritating.

Reckon that would be it. My 850 can be quite loud when warm - not cold or hot - due to this cause.

Sounds terrible. Said to be harmless.

[redliner1973]

Mine does the EXACT same thing, been doing it since I got it. Sounded to me like it comes from around #2 cylinder area...It's never gotten worse or better, so I always attributed it to those "Noises" so common with this engine.... :twisted:

[Anonymous]

well, thanks for all the ideas. I'll tear into it some this weekend. It's just that it's a new noise and that bugs/worries me.
Have a great weekend everybody!

[Anonymous]

Mine does that too, always has but maybe to a lesser degree. Sitting at idle, every 10 seconds for about 1 second sounds like a rod knocking. Never got worse, only does it at idle. Does it every time. My bike has less than 20k on the clock.

[HiSPL]

Instead of a stethoscope, use a long piece of fuel/vacuum line. stick one end in your ear and use the other end to probe for the noise. This works surprisingly well.