[62321]

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This is my first post on this forum. I have been reading this forum for about a year now and have gotten alot of good information from just reading. Now I need help with a problem with my wing. Last year I purchased a 1982 GL1100. When I bought the bike it had a knock in the motor. At the time I didn't think it was a problem and I still am not sure it is. The noise sounds like a rod knocking. The motor sounds fine from about 1000 rpm to about 2800 rpm. Then past that the knock starts. It only seems to be present when you give throttle and isn't there when you have backpressure on the motor. Is this a normal sound? The knock seems louder on the right side. The bike seems to run fine with plenty of power. Could the carbs need adjusted? Any help you could give would be appreciated. I sure don't want to tear down the motor if it doesn't need it. The bike has 37000 miles on it. Thanks

 

[exavid]

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:waving::waving:Glad to see you convert from a lurker to a participater!:waving::waving:

I don't think what you're hearing is a rod, usually with a rod going out it's loudest and most noticeable when you float the throttle, i.e. not quite acceleratingand not quite decelerating. The fact that it's loudest on the right tends to support this. I'd try the stethoscope method with a screwdriver or a mechanic's stethocscope to see if it's possible to localize the noise. Try cranking the engine with the spark plugs out, do you still get the sound? If you can hear it on the starter it might be easier to localize than with the engine running. If it were my bike I'd look at the plugs to see if there's any difference such as the right side running hot to to a lean mixture, if the plugs ceramics on that side are white it would indicate the carbs need a look at. If they all look the same I'd pull the timing cover and take a look at the belt timing. Next would be the right valve cover to see if all's well with the rockers and valves. If none of this located the problem it would seem a logical step to pull the head and see if there's any damage to the valves or pistons. One other check would be to check the actual idling oil pressure. Screw a gauge in place of the oil pressure sensor and check the pressure. If you had a bad rod it's likely to be pretty low, especially at idle.

 

[Graham B]

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I'd go along with what Exavid says but I would ask what you mean by knocking? Sometimes it's not easy to translate the sound into words. So I'd do some non-invasive checks first;

Inlet manifolds all tight (top and bottom)?

Exhaust all tight and no leaks?

Oil and water staying where it should be and the right colour?

Compression all OK and even across all four pots?

Carbs balanced?

Good luck.

 

[twisty]

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62321 wrote:

This is my first post on this forum. I have been reading this forum for about a year now and have gotten alot of good information from just reading. Now I need help with a problem with my wing. Last year I purchased a 1982 GL1100. When I bought the bike it had a knock in the motor. At the time I didn't think it was a problem and I still am not sure it is. The noise sounds like a rod knocking. The motor sounds fine from about 1000 rpm to about 2800 rpm. Then past that the knock starts. It only seems to be present when you give throttle and isn't there when you have backpressure on the motor. Is this a normal sound? The knock seems louder on the right side. The bike seems to run fine with plenty of power. Could the carbs need adjusted? Any help you could give would be appreciated. I sure don't want to tear down the motor if it doesn't need it. The bike has 37000 miles on it.

Welcome to the forum 62321, your noise could be about anything. I'm not sure how many miles you have ridden it with that knock but in most cases if you actually had a rod knocking it would have gotten much worse after some miles. A rod knock also usually gets worse as the engine heats up. Without hearing the noise myself I would lean more towards a primary chain knock (common on those 1100's).

Start with a valve adjustment (that might help) then try to isolate the area it is coming from.

In the mean time you might put the word KNOCK in the search box at the top of this page & read till your eyes water as there are others with the same issues.

Twisty

 

[Patch]

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I'm so glad that I read this thread this morning. My new (to me) 84 Aspencade has a slight knocking sound.

EXAVID, my noise seems most noticeable when I float the throttle. During acceleration, I do not hear it and when deceleration, I do not hear it. It is most pronounced on the right side. The engine starts fairly good and idles good without any knocking noise. I do not hear it until I am at speed and am neither accelerating or decelerating. It is very hard trying to locate this since I have to be actually riding before I hear the sound. Have not tried putting the bike on the center stand and running it there. I have read on this fourm that the fuel pump can make a nocking sound. It is on the right side.

Any thoughts?

 

[62321]

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Thanks I will try all the things mentioned. I was also wondering like csanders67217 if it might be the fuel pump?

 

[exavid]

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Hard to see a fuel pump making that much noise, but anything's possible. It's a matter of eliminating possible causes and investigating those you can't eliminate. A failing rod end or wrist pin could cause it but it's uncommon on these engines. Do you get the noise with the bike moving on the road but with the clutch pulled in, or coasting with the bike out of gear? Try running it on the stand to duplicate the problem but be VERY CAREFUL to have the bike up against a wall or tied down in case it shook itself off the stand.

What you have to do here is consider the engine's anatomy and what could make a noise. Is the noise in step with the engine rpm or the drive line? Could it be a U-joint? There are a lot of things here to consider. Try to do some more investigating and bring the results back to the forum, perhaps with more information one of us can get lucky and figure it out if you don't first!

 

[mag]

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Are all cylinders firing? Definitely check for carb synch. Mine was making the same noise from #1. Synch cleared it up. Also check for proper voltage, vaccum leaks (spray around carbs/intakes with wd40 or carb cleaner) and make sure your ignition timing is on.