Ratteling engine noise GSX 1100 1981 only then cold

[Anonymous]

Re: Ratteling engine noise GSX 1100 1981 only then cold

Hi,

Bike is GSX1100 1981

I (my brother) have a rattling noise in the engine when it is cold, the bike has behaved like that for 4 years, I have also asked this question here before but now some more checks are done.

The engine rattles badly then cold, runs perfect then warm.

We have checked:

Cam chain, cam tensioner, starter clutch, clutch and valves.

I have been told that it could be the crankshaft axial-bearings that make the crank moving in axial direction????

Any suggestions where too look next?

Hi Kaz,

Is the noise only there when on side stand?.
I undestand that the cams float a little in the carriers and can intermittently rattle when cold and on sidestand.
Also does your engine have a starter chain, thay rattle as well.

Phil

[Anonymous]

So where do we go from here???

[Anonymous]

Re: Ratteling engine noise GSX 1100 1981 only then cold

Hi,

Bike is GSX1100 1981

I (my brother) have a rattling noise in the engine when it is cold, the bike has behaved like that for 4 years, I have also asked this question here before but now some more checks are done.

The engine rattles badly then cold, runs perfect then warm.

We have checked:

Cam chain, cam tensioner, starter clutch, clutch and valves.

I have been told that it could be the crankshaft axial-bearings that make the crank moving in axial direction????

Any suggestions where too look next?

Hi Kaz,

Is the noise only there when on side stand?.
I undestand that the cams float a little in the carriers and can intermittently rattle when cold and on sidestand.
Also does your engine have a starter chain, thay rattle as well.

Phil

Hi all of you Im KZ?s brother (whit the rattling noise in the engine), thanks for all your replys.

Phil, no it?s all the time when it?s cold and I dont have a have a starter chain.
As I can understand I will continue drive the bike as it is.

[Anonymous]

With the low pressure oil delivery system that the GS uses, I believe that it is all top end noise. When the cams and shafts warm up and expand the tolerances tighten up and the "slop" dissappear. Mine has a little of what you describe if I let it slog away below 1000 RPM. But then I am happy with the way she runs with 54000km on the gauges.

Mine passed emissions and now I am trying to get it to run better. Sure is difficult to get the jets set correct when you are just guessing. Any ideas?

[kz]

Re: Ratteling engine noise GSX 1100 1981 only then cold

Hi all of you Im KZ?s brother (whit the rattling noise in the engine), thanks for all your replys.

Phil, no it?s all the time when it?s cold and I dont have a have a starter chain.
As I can understand I will continue drive the bike as it is.

Hi Hasse,

So you finally find your way to the GSResources.

[Anonymous]

Mine passed emissions and now I am trying to get it to run better.

Motorcycles are exempt from emissions testing here in BC. Where are you?

[Anonymous]

Just a word about engine noise when cold. I'm not a metalurgist, but do know something of physics, so I'll try to explain this in a way I that makes sense to all of us.

We probably all know that materials, metals in particular, expand when heated and contract when cold. Well, different materials expand and contract at different rates - called coefficients of expansion. Let's take two in particular, steel and aluminum. (Please keep in mind that there are all kinds of different alloys in each category and each has a modified set of coefficients - I'm keeping this conversation general). Steel has a coefficient of expansion of 15-18 millionths per degree C. Aluminum is in the range of 18-23.

Now, engineers, when they design an engine, set the tolerances and dimensions at an operating temperature. Since from the coefficients above we can see that aluminum expands faster than steel, (larger coefficient) so at low temperatures the tolerances are greater. (If the tolerances were tighter at low temperatures, then when the engine warmed up it would sieze). This tends to explain why at lower temps the engine makes more noise.

Another fact to consider. Forged pistons and cast pistons hav different coefficients of expansion also. This is why forged pistons make more noise than cast at lower temperatures.

[Dink]

One suggestion for you. Try a manual camchain tensioner it may not totally remove the noise but it may help a lot.
Dink

[Anonymous]

Sound can be deceiving and it echos. I had a rattle once years ago and it ended up being in the tranny.

[kz]

Sound can be deceiving and it echos. I had a rattle once years ago and it ended up being in the tranny.

Jon,

Thanks for your answer, but I don't understand the word "tranny" could you explain to a Swede please?

[kz]

One suggestion for you. Try a manual camchain tensioner it may not totally remove the noise but it may help a lot.
Dink

Hi Dink,

Have dismounted the Cam tensioner and it seems too work as it should, if I turn the cam tensioner while running (I know I have to adjust it afterwoods and that I shouldn't do that during running).

It has no influence on the noise.

[Anonymous]

Sound can be deceiving and it echos. I had a rattle once years ago and it ended up being in the tranny.

Jon,

Thanks for your answer, but I don't understand the word "tranny" could you explain to a Swede please?

It is what trails behind a woman i think??? always shifting up and down

[skip]

Have you tried a mechanics stethescope to pinpoint were the rattle is coming from? If you can find one that is amplified with the headphones use it they work great.

[kz]

Have you tried a mechanics stethescope to pinpoint were the rattle is coming from? If you can find one that is amplified with the headphones use it they work great.

I have tried with a sreewdriver and always thought it was the cam chain.

Now, I must say i believe you guys, that it is nothing to worry about, and will keep on driving, maybe the bike has forged pistons??

BTW:

After all, it is my brothers bike, and I got him to post at least one post here and say thank you to you all for your replys.

BTW2:

My GS 1150 doesn't have rattle at all (in comparisament) and my GS 1150 has approx. twice the milage as my brothers bike, really big difference actually.....

[kz]

It is what trails behind a woman i think??? always shifting up and down

I think I understand, but not sure... :roll: