Knocking sound at idle?

[sschering]

My 79 GS100 sounds like a box of rocks when it's cold and I let the idle drop below 1000 rpm.. I still need to do valves and a vac sync.
Looks like I'll add check the clutch hub nut to the list.

 

[GS750cafe]

Wow! Thanks for all the input guys. I have not synced the carbs yet. I need to rejet as well. There is most definitely an exhaust leak that I'll get to. I was thinking of tweaking the exhaust a bit first - maybe shortening and then adding some baffles to reduce noise (is this a bad idea?). Then I'd get into the carbs. I've had a 1991 gsxr 750 that had some noisy valves, but was such a work horse that all I did was ride it and smile! The interesting thing with this ticking is that the engine has got to be really warm before I start hearing it...

 

[chuck hahn]

Scott..the clutch basket MAY be fine.. the combination of valves needing adjusted and the carbs being out of sync will produce some really harsh noises. Also check the timing while doing the tune ups!! In my opinion..and mine only.. I feel that the time it takes to pull the basket and check the springs its well worth removing that worry from the equation. You can pull everything and have it back together in a matter of an hour or so and a 12 dollar gasket. These bikes are awesome, but i have learned that they need to be tuned in well or they will make funny noises..and thats the beauty of them. They will definitely let you know when you have lapsed on the maintenance by making noises.

 

[49er]

Wow! Thanks for all the input guys. I have not synced the carbs yet. I need to rejet as well. There is most definitely an exhaust leak that I'll get to. I was thinking of tweaking the exhaust a bit first - maybe shortening and then adding some baffles to reduce noise (is this a bad idea?). Then I'd get into the carbs. I've had a 1991 gsxr 750 that had some noisy valves, but was such a work horse that all I did was ride it and smile! The interesting thing with this ticking is that the engine has got to be really warm before I start hearing it...

Just listened to your video. That's cam walk.

If you want a fix, visit Basecliff's site for the details.

If you can live with the noise, just sync the carbs and ride it.

 

[cyclefvr2]

im going to say check the timing chain adjuster,im sure at 12k or so it will need set again
if carbs need set do that as well, its not hard on those carbs, just follow the book,
1 of the BIGEST problems is crappy fuel!, go with the highest octain at the pumps, and a good station, this alone is going to get rid of a ton of clunkity clunks
i dont think its cam rattle, though

 

[tkent02]

im going to say check the timing chain adjuster,im sure at 12k or so it will need set again
if carbs need set do that as well, its not hard on those carbs, just follow the book,
1 of the BIGEST problems is crappy fuel!, go with the highest octain at the pumps, and a good station, this alone is going to get rid of a ton of clunkity clunks
i dont think its cam rattle, though

What a crock of B.S.
Cam chain adjusters don't need reset, they either work or they don't.
Use low grade gas, it's a low compression engine.

 

[1948man]

What a crock of B.S.
Cam chain adjusters don't need reset, they either work or they don't.
Use low grade gas, it's a low compression engine.

Don't be vague and beat around the bush. Just say what's on yer mind.

 

[chuck hahn]

Tom is basically correct on the cam chain tentioner. They can however get gummed up and stuck in a loosened state. Find the tutorials posted here and clean the tentioner if you so desire. Also remeber that once you get the screw to touch off on the adjustment, to back it off about 1/4 turn and then tighten the jam nut. They are supposed to work on a spring system and if its just locked tight against the rod and jam nutted there it wont float and do its job properly.

 

[Nessism]

Cam walk on a 12k mile engine? Doubt it.

Since this is a new bike to you I strongly suggest the following: carb sync, rejet for pipe, adjust the valves, pull the cam chain tensioner and make sure it's springing outward as designed. This is all basic maintenance and needs to be done regardless. Build a base with solid maintenance and then worry about things like noises second.

 

[49er]

Cam walk on a 12k mile engine? Doubt it.

Since this is a new bike to you I strongly suggest the following: carb sync, rejet for pipe, adjust the valves, pull the cam chain tensioner and make sure it's springing outward as designed. This is all basic maintenance and needs to be done regardless. Build a base with solid maintenance and then worry about things like noises second.

Older members who have owned these bikes from new back in the day, reported excessive endfloat clearances on some models, ex the factory.

I have done good research on this problem, and have offered a realitively cheap fix. Believe me, that noise is cam walk, from excessive camshaft endfloat.

Low mileage engines can be afflicted with this problem, especially if whey have spent a lot of time idling while perched on the side stand.

 

[cyclefvr2]

What a crock of B.S.
Cam chain adjusters don't need reset, they either work or they don't.
Use low grade gas, it's a low compression engine.

do you ever work on bikes?
have you ever done any f#in maintinence? lol
low com? i know for a FACT they run better with high grade fuel,
make sure you know what your talking about b4 you try to critisize someone

chain adjusters work or dont?? WTF... get real

 

[cowboyup3371]

Hey Cycle, have you SEEN Tkent's garage? I have and trust me, that man WORKS on bikes. He's got more in that garage than most people have in other toys around their entire house. Might not want to call someone out until you know what they really do.

 

[tkent02]

do you ever work on bikes?

Pretty much every day since the new workshop was built.

have you ever done any f#in maintinence? lol

Completely restore several bikes a year, engines, suspensions, electrical systems, paint, the whole works.

low com? i know for a FACT they run better with high grade fuel,

You should tune your bike correctly. If it runs better on high test there's something wrong with it. A stock GS, or any other low compression engine in good working order runs better, has more power, gets better fuel mileage and stays cleaner inside with low octane fuel.
My guess is you are comparing cheap gas with a very high alcohol content to expensive gas with none. Then it may run better. It's the alcohol, not the octane rating.

make sure you know what your talking about b4 you try to critisize someone

I wasn't criticizing you, just pointing out that your post was incorrect. If I was criticizing you, you would have known it.

chain adjusters work or dont?? WTF... get real

They are fully automatic, they keep the chain adjusted without any adjustments or resetting. Unless they don't work, or get stuck, or the spring breaks. In that case it needs to be repaired. So yeah, it either works or it doesn't.

 

[cyclefvr2]

tkent--

then why would you say what you said!, timing should be checked, even if just to be safe, its always nice to check botls as well these bikes are rode every day

 

[tkent02]

tkent--

then why would you say what you said!, timing should be checked, even if just to be safe, its always nice to check botls as well these bikes are rode every day

I didn't say anything about timing, of course the timing should be checked, along with every other adjustment. I thought we were talking about cam chain adjusters and regular gas?
Don't know much about checking the botls, what are they?

 

[cyclefvr2]

I didn't say anything about timing, of course the timing should be checked, along with every other adjustment. I thought we were talking about cam chain adjusters and regular gas?
Don't know much about checking the botls, what are they?

no i just suggested he checked the tensioner, the fuel ,i know for a fact they run better on high octain i use it, it helps get rid of the chucka chucka sound, and poor idle
no i suggest checking all bolts , as they work loose over time, and mine was loose as well
it was just a suggestion as i couldnt tell exactly what it could be

 

[tkent02]

If it works for you, that's wonderful.
Chucka chucka and a poor idle?
I thought you knew how to do maintenance.
Perhaps you are riding a Harley now.

A Harley should sound like, "Potato, potato", not "Chucka, Chucka".
Maybe you need to adjust the cam timing.

 

[Buffalo Bill]

For cryin' out loud?I had a good laugh!

For cryin' out loud?I had a good laugh!

Don't stop now boys, put on another reel!

 

[cyclefvr2]

If it works for you, that's wonderful.
Chucka chucka and a poor idle?
I thought you knew how to do maintenance.
Perhaps you are riding a Harley now.

A Harley should sound like, "Potato, potato", not "Chucka, Chucka".
Maybe you need to adjust the cam timing.

nope, your not much of a mech are ya, all jap bikes sound that way sooner or later, blow smoke up someone elses ass k

 

[tkent02]

nope, your not much of a mech are ya, all jap bikes sound that way sooner or later, blow smoke up someone elses ass k

Chucka Chucka Chucka, never heard that before.
Japanese bikes, Engish bikes, German, Italian, Czech, even the Chinese junk doesn't do it.
Maybe you can record this Chucka Chucka sound so we can help you identify it?