850 Engine Noise

[Gorminrider]

Gs650-camwalkfix-reverseCamendSeals-2-20190328.jpg

...quite a close fit but not quite touching. I expect if they do have an effect, they will wear. But it's merely an experiment..to see if they "work" and then to pursue the idea or not....

Maybe, they will work as is and just want replacing at valve adjustment periods.I'd be happy enough with that.

So far, a test is hopeful but naturally, I expect failure -it's just too easy to merely turn these around and call it "fixed" !

[John Park]

I was fiddling with an early 400 head and, if you remove the locating dowels on a cam end cap, there is enough lateral play to get to the thrust face. The dowels are there because they provide stability during boring and replicate the location nicely. Some engines don't use them [Kawasaki?] and just use the journal to align them. Perhaps it would be possible to remove them on this engine and slide them over to take up the endplay.

Maybe a bowed plate of springy metal in there with a ball just large enough to clear the end of the cam? I'm a bit nervous here because on a twin the space behind the half moon goes nowhere, but there's nothing here to prevent whatever you'd put in from touring the cam and bucket; imagine a bearing ball trying to get involved with that?

[Gorminrider]

if you remove the locating dowels on a cam end cap, there is enough lateral play to get to the thrust face

hmmm. a little more than I want to do YET but I'll make a note! Here's an existing fix using shims from a GS member-note the big gap that is causing this noise!...but I want E Z ier if I can..
Camfloat tapping fix with shims gs 750 cylinder head.jpg

"springy washers" at the cam ends were my very first thought..(post22) but holding them with the existing plastic caps is not on. I wonder if a "spring clip" of some sort might just fit right in to the "offending" gaps (per picture above) if they could be held without me needing to drill +tap straight holes into crucial parts with my blackndecker hand-drill! Yes, I CAN do it but I want something a little less invasive
... The ball bearing and spring is still an idea but again, not using these rubber caps.

Right now, I'm inclining t'wards slipping hard plastics in at the ends in my dream-schemes because they are easier to shape (could be square pieces) and "sacrificial" in action-they will just soften,wear, and get out of the way if they are really pushed so it seems less risk of wear+splits, popouts+flights around inside.

[Grimly]

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So far, a test is hopeful but naturally, I expect failure -it's just too easy to merely turn these around and call it "fixed" !

After I had one of those rubber end caps blow out on me a hundred miles from home and no way to fix it, so consequently had to be trailered back, I refitted all four with new ones that were reversed.
None of the ever blew out, in that bike or since.

[93Bandit]

After I had one of those rubber end caps blow out on me a hundred miles from home and no way to fix it, so consequently had to be trailered back, I refitted all four with new ones that were reversed.
None of the ever blew out, in that bike or since.

What causes those to blow out? There shouldn't be any pressure under the cam cover.

[Steve]

I have often wondered the same thing, yet I still see reports every so often.

If pressure is building up, you must have TWO problems:
1: the breather tube on top of the valve cover is blocked
2: you have an incredible amout of blow-by getting past your piston rings.

I would think that by the time you have that much blow-by, you could probably get a job with the city or county in the mosquito control department.

.

[Gorminrider]

Any beneficial effect on the cam-clatter, Grimly?....they certainly won't come out when reversed and seem to seal as well.

[Grimly]

What causes those to blow out? There shouldn't be any pressure under the cam cover.

Not sure, as the crankcase was vented properly, but it was likely it was a used one put back in and insufficient sealant holding it in place.
I didn't have that bike long at that point, so don't recall if I'd done the shims or had a shop do them (as happened once or twice when I was busy), so who knows who did what - the answer is lost in the mists of time.
Given I'm utterly sure of the lack of crankcase pressure, it must have been bad fitment.

[Grimly]

Any beneficial effect on the cam-clatter, Grimly?....they certainly won't come out when reversed and seem to seal as well.

Not that I noticed.

[93Bandit]

Hey guys. I have another top end noise question, figured I would use this thread as the title is applicable.

Before changing the bucket shims on my 850, the top end had a lot of tapping/clatter noise which I assumed was excessive clearance in the valve train. The noise was only present after the engine warmed up, and got louder as engine speed increased. When I checked the bucket shim clearances, they were between .006-.008" on all valves. I put in new shims and got all within spec, except for one being slightly loose at .004".

The top end is much quieter now that they're all in spec, however I noticed on a warmer day after an hour long ride, the top end noise was back, although not nearly as loud as before. It's also not present under all conditions, I mostly noticed it at low rpm, below 2,500. Are the 850's considered somewhat noisy? Should I be concerned with this noise?

If I need to, I might be able to take a video of the bike running to capture the sound, but I've only noticed it while riding so it's probably not a good idea to try to video the bike while riding...

Thanks guys!

[Gorminrider]

Your description sounds like the bike is warmed up is all.... there has to be some noise at the valve rockers epecially with the bucket shims or you won't be sure the valves are closing completely. Kind of like your clutch cable adjustment....it's almost impossible to get perfect, without any slack for all conditions.
It might be as simple as: When your bike has settled to it's maximum temperature so has your multigrade oil made its best guess on how thick it should be...

[Steve]

"Noise" is rather subjective. Some like the way the engine sounds and call it "music", while others prefer the silky silence of a Goldwing and think an air-cooled engine is "noisy".

Bringing your valve clearance down from 0.008" to 0.004" (and less) was a good move.
It will definitely make it quieter. Engines do change sound as they warm up. If it does not sound obnoxious, it's probably not. It's possible that you might be experiencing the infamous "cam walk". Does the sound come and go? Mine will knock a few times, wait about 5 seconds, knock a few more times, etc. As the engine speed is raised a bit, the noise goes away, By the time I cross 2000 RPM, I don't hear it any more. Yours might be doing the same thing. In fact, it might have been doing it all along, but it was masked by the large valve clearances.

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[93Bandit]

"Noise" is rather subjective. Some like the way the engine sounds and call it "music", while others prefer the silky silence of a Goldwing and think an air-cooled engine is "noisy".

Bringing your valve clearance down from 0.008" to 0.004" (and less) was a good move.
It will definitely make it quieter. Engines do change sound as they warm up. If it does not sound obnoxious, it's probably not. It's possible that you might be experiencing the infamous "cam walk". Does the sound come and go? Mine will knock a few times, wait about 5 seconds, knock a few more times, etc. As the engine speed is raised a bit, the noise goes away, By the time I cross 2000 RPM, I don't hear it any more. Yours might be doing the same thing. In fact, it might have been doing it all along, but it was masked by the large valve clearances.

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Steve, if you recall the original question in this thread, cam walk is what we determined the idle noise is. That noise comes and goes and sounds exactly like the video that was posted.

The noise I'm talking about now is definitely valve train clatter. It's exactly what I heard before shims, but much much quieter and mostly unnoticeable. I'm just used to auto engines that are quieter. This is my first air cooled engine. If they're inherently more noisy, I'll get used to it. Just wanted to make sure I don't have anything coming apart.

[Steve]

I'm just used to auto engines that are quieter. This is my first air cooled engine. If they're inherently more noisy, I'll get used to it. Just wanted to make sure I don't have anything coming apart.

(Most) Car engines are a LOT quieter.

Air-cooled engines are noisier. Compare an old VW Beetle to a newer Subaru.
Same type of engine, Subbie is water-cooled.

Bring it on down when the weather warms up a bit, we can check it out in detail.

.

[Gorminrider]

one member's fix- paraphrasing, I think he said "turning the cam-end rubber around"

Reporting back, I've finally insured the 650 and during a 40 mile ride this worked! I simply reversed the cam-end plugs as shown in post 30 (https://www.thegsresources.com/_foru...06#post2535606)

My bike would start the cam-walk clatter as soon as the bike was warm,but since doing this, I haven't heard it . Plus, a proper ride yesterday inclines me to report this simple fix is worth investigating for others annoyed by it.
As to "long-term" and "risks" I can't say until it exhibits something or until I take the valve cover off, but even if it wears the plugs away between valve-checks, I'd say it's worth it.