850 Engine Noise

[Steve]

All I can say for sure is that I can't hear it once the bike is moving, so it must not really matter.

.

 

[Gorminrider]

I replaced all the shims on my 450 with new OEM gs500 ones which appear to be some sort of sintered metal [??] and the cam walk racket went away and has never come back

. That sounds very hopeful. I wonder at the "why" of it...friction coefficient? I know you use hi-grade oil too, if this might have any effect..

and various measures were tried by Suzuki such as a sprung endplay shim to cure it

this is something that comes to mind.. I'm keeping an eye out for thin "warped" spring washer for each cam end maybe just glued to the rubber end seals...... or maybe just bit's of hdpe as experiments... It kind of agrees with one member's fix- paraphrasing, I think he said "turning the cam-end rubber around" .

It's also been said that leaning the bike over removes the noise....I haven't experimented with this but it'd be a demonstration to anyone that the noise they hear is indeed "cam-walk" and would save posting (or trying to listen to) Youtube videos...
The documented"machinist" option is never going to happen in my shed .

 

[Steve]

It's also been said that leaning the bike over removes the noise....I haven't experimented with this but it'd be a demonstration to anyone that the noise they hear is indeed "cam-walk" and would save posting (or trying to listen to) Youtube videos.

If leaning the bike over removes the noise, it must have to be leaned over farther than what the side stand allows. :-k

My wife's bike does it the worst of our three bikes, it is plainly audible while on the side stand.
Usually not very noticeable when cold, it's louder when the engine is warm.

.

 

[93Bandit]

If leaning the bike over removes the noise, it must have to be leaned over farther than what the side stand allows. :-k

My wife's bike does it the worst of our three bikes, it is plainly audible while on the side stand.
Usually not very noticeable when cold, it's louder when the engine is warm.

.

Mine is the same. I've noticed no difference between the bike on the side stand vs. sitting at a light with the bike vertical. If the engine is up to temp and idling, it clatters.

However I'm no longer worried about it. I was only concerned because I didn't know what the source of the noise was. Now that it's clear it is caused by cam walk, and many members here have the same noise with no obvious ill effects, I will continue to ride into the sunset without worry.

 

[Gorminrider]

A sidestand lean makes no diff to my (warm) bike either but I do think I saw as a single post in a thread- it wasn't said how far the bike needs to be leaned...up to 45 degrees I'd guess so it's not something I'll do on gravel.

I can live with the clatter, but I don't like it.

 

[Guest]

A sidestand lean makes no diff to my (warm) bike either but I do think I saw as a single post in a thread- it wasn't said how far the bike needs to be leaned...up to 45 degrees I'd guess so it's not something I'll do on gravel.

I can live with the clatter, but I don't like it.

On a twin, I had the evil thought of slightly slotting the dowel holes on one of the cam caps and sliding it inwards to take up the endplay. You'd still be left with whatever develops from expansion, but at least you'd be starting at zero. Not having a four about to examine, I couldn't tell you if there would be a similar relevancy.

By the look of it, you'd have to move over about .020 or .5mm to get 'there' and then whatever clearance there is. Not really a job for a round file unless you are patient and talented.

My spare engine head is from an '80 and a set of late 80's cams fit in with zip endplay; weird but I'll take it. Now I just need a reason to build the motor up and swap it in, but the wear rate on me seems higher than on these motors...

If I were really in a state of annoyance I'd consider making a replacement half moon with a spring loaded ball bearing to sit in the cam center hole. It wouldn't be that hard if you made a round plug with an o ring groove and then milled off half the circle. The effect would be similar to having the bike leaned way over all the time, and even if the ball fell out somehow it has nowhere to go.

BTW, I missed which model of bike you're having the problem on. 650 twin?

 

[Gorminrider]

John, OP has an 850, but yes, I have a 4 too- a 650G that at first I used to wonder if people alongside at the light were thinking, "Nice bike-too bad the thing it needs engine work"

...of course they are not, with the windows rolled up in diesel pick-ups, airconditioning on, and yacking on their cell-phones.

a spring loaded ball bearing to sit in the cam center hole

Beauty! keep it up man! I'm thinking on my spring collection already! Ball bearings, I have a-plenty...I wonder just what side force is required to "control" the cam's travelling ?
The ball bearing idea is a worthy start! With the rubbers off, I might drill a hole for a spring into a broomstick and just push the ball bearing against the cam for a test...

 

[Guest]

Beauty! keep it up man! I'm thinking on my spring collection already! Ball bearings, I have a-plenty...I wonder just what side force is required to "control" the cam's travelling ?
The ball bearing idea is a worthy start! With the rubbers off, I might drill a hole for a spring into a broomstick and just push the ball bearing against the cam for a test...

I don't think you'd need much force at all. An insert to fill the space between the half moon and cam, with a hole to hold the ball captive and a spring against the reversed half moon might be something simple enough for us rustics to cobble up.

 

[Gorminrider]

I've got the 650 in the shed now, (cleaning up the rear brake etc. before reinsuring this year) so the timing is good to do some tinkering as well....

 

[Gorminrider]

well, refreshing my memory of these cam-end seals with reality, I see that the "meat" for

An insert to fill the space between the half moon and cam, with a hole to hold the ball captive and a spring against the reversed half moon might be something

isn't available without a little more thought-these cam-end seals are hollow construction...so they'd want to be filled up with something. MEANWHILE, simply reversing them as a learning exercise is too easy an idea to pass up..here shown reversed- and the next post due to picture limit.

 

[Gorminrider]

...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" !

 

[Guest]

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..


"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]

.

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!