Cam walk, options?

[Guest]

I'm getting the famous cam walk tapping at idle. Cold, or once it's fully hot, it's fine, but rather annoying when you're just puttering around on short trips. Interestingly, I can feel it tapping with my finger on the cam end covers, mostly the left intake.

While many theories abound, my take is that the cam lobe is offset a bit to the bucket in order to make it rotate. That's the beauty of bucket tappets; they present a continuously different face to the cam to keep things cool. But in the process there is a certain side thrust generated, especially if the bucket isn't perfectly parallel to the cam lobe.

In this case, I can hear the noise come and go as the bucket rotates, which indicates that one shim or bucket may not be perfectly square.

The fix I've heard of is to get the shim washer that GS500s have [?] and machine the thrust face of the cam to end up with less endplay. It's a 1mm shim as I recall. But measuring another head I have, the endplay stock is about .012 so why not use a .010 shim washer - or whatever thickness is appropriate - and just leave the cam stock? I can't see how the endplay is really critical considering the head expands way faster than the cam, so a few thou cold ought to be enough.

Any thoughts from those who have been there?

 

[Guest]

I have no insight for you, but I presume you have visited cliff's page and the end float mod outlined there? here is a link if you haven't:
http://members.dslextreme.com/users/storagecliff/images/cam_end_float_mod.pdf

good luck!

 

[Steve]

If you can hear it while "puttering around on short trips", your ears are a lot better than mine. :-k

My wife's bike has had noticeable cam walk noise since we got it over 10 years ago. Only happens at idle. By the time the engine hits about 1800 RPM, it's gone. Since virtually all of our riding happens well over 2000 RPM, we never hear it. When stopped at a light, if it happens, it's simply accepted as part of the noise(s) that the bike makes.

Oh, in the past 10 years and about 25,000 miles, the noise has not gotten any worse, so it's not much to worry about.

.

 

[Guest]

If you can hear it while "puttering around on short trips", your ears are a lot better than mine. :-k

My wife's bike has had noticeable cam walk noise since we got it over 10 years ago. Only happens at idle. By the time the engine hits about 1800 RPM, it's gone. Since virtually all of our riding happens well over 2000 RPM, we never hear it. When stopped at a light, if it happens, it's simply accepted as part of the noise(s) that the bike makes.

Oh, in the past 10 years and about 25,000 miles, the noise has not gotten any worse, so it's not much to worry about.

.

I meant that it only does it when the engine is half warmed and at idle. So it's obvious at stoplights and such in town. I realize that it's unlikely to get worse and does no harm, but I'm building up another engine next winter and would like to avoid it with the least amount of fussing about.

 

[Guest]

I have no insight for you, but I presume you have visited cliff's page and the end float mod outlined there? here is a link if you haven't:
http://members.dslextreme.com/users/storagecliff/images/cam_end_float_mod.pdf

good luck!

I can't imagine going to all that trouble when a simple endplay spacer washer would achieve the same result. My only worry would be that if the spacer piled up somehow you could end up with bits in the cam chain.

There is no significant end load, and the cam is only turning 4500 at redline and 2500 - 3000 at cruising speed. It shouldn't be too fussy.

 

[Guest]

Suzuki makes a series of endplay washers for the GS500 - 22X28mm - from 1.0mm in .1mm increments to 1.3mm and also a .7mm. Then there's a wavy washer to spring load it if you want to. You can either mill something off the cam thrust face or put the washer in a surface grinder, which I have access to and is simpler and keeps the cam stock.

I don't have a Four handy to look at, but it seems like these washers would also work the same way on them. However, the 450 doesn't have an idler sprocket like many fours do so you'd have to be careful to not shim the cam to one side and disrupt the natural flow of the chain. That's possibly why Suzuki left so much endplay in there in the first place. But you could turn the motor through a few revolutions and then measure the clearances on each side.

Still hoping to hear from someone who has done this?..????

 

[tkent02]

I wear earplugs.

 

[Steve]

However, the 450 doesn't have an idler sprocket like many fours do ...

I could be mistaken, but I think it's only the early 750s (the two-valve ones) and the 850s that have the idler.

.

 

[BillH]

I have the same thing in mine. When it does it, it sounds like it mostly coming from the intake camshaft on the right side. It sounds terrible, at first you would think it's a rod knocking. It's embarrassing needless to say. I think I hear a cam chain noise too when the engine is cold. Going to go over it very closely next time I take the valve cover off. Like everyone else's, the sound goes away over 1500 or so RPM. And after the engine is fully warmed up you can't hear it.

https://www.youtube.com/watch?v=uGqVqGSnJn4

 

[GregT]

Just a point - before going to the trouble of machining things, check that you haven't got an undersize shim.
Way back, I found a couple of yamaha shims fitted to a GS - about .5mm undersize on the OD...rattle city.

 

[tkent02]

Suzuki makes a series of endplay washers for the GS500 - 22X28mm - from 1.0mm in .1mm increments to 1.3mm and also a .7mm. Then there's a wavy washer to spring load it if you want to. You can either mill something off the cam thrust face or put the washer in a surface grinder, which I have access to and is simpler and keeps the cam stock.

I don't have a Four handy to look at, but it seems like these washers would also work the same way on them. However, the 450 doesn't have an idler sprocket like many fours do so you'd have to be careful to not shim the cam to one side and disrupt the natural flow of the chain. That's possibly why Suzuki left so much endplay in there in the first place. But you could turn the motor through a few revolutions and then measure the clearances on each side.

Still hoping to hear from someone who has done this…..????

They would have to fit past the first lobe of the cam, to get to the cam cap which is the thrust surface. Maybe I'm not understanding you correctly?

 

[Guest]

Just a point - before going to the trouble of machining things, check that you haven't got an undersize shim.
Way back, I found a couple of yamaha shims fitted to a GS - about .5mm undersize on the OD...rattle city.

Thanks for the hedzup; my bag of spare shims came as a grab bag with some obviously huge OD ones in there from who knows what. I'll check.

 

[bwringer]

I wear earplugs.

Same here. This is not a problem worth solving.

 

[Guest]

Same here. This is not a problem worth solving.

In your opinion. Because it seems to be so difficult to fix, many - including Suzuki - have deemed it an innocuous annoyance. Which it is. If I can fix it with a few OEM washers on a twin, your opinion about it on fours may be irrelevant.

It's worth it to me.

 

[tkent02]

Let us know wham you have it figured out.

 

[Guest]

I never had an issue with this but I knew someone with a 450 that did and I've heard why it's annoying.

I have 2001 GS500 cams in my 450 now and they come with the shim. I had 1.1mm shims with the cams and it wouldn't fit, just a smidge too wide, so I dropped to the 1mm shims and both were pretty much a perfect fit so still no cam walk.

If you want to get rid of it, then yes the 500 shims will do it, but they will need to be machined down quite a lot to fit with the 450 cams.

Of course you could just get some 500 cams and get a little tweak to your performance at the same time

 

[tkent02]

Of course you could just get some 500 cams and get a little tweak to your performance at the same time

As long as you're in there, might as well throw in the 500 pistons an cylinders that come with the cam.

 

[Guest]

As long as you're in there, might as well throw in the 500 pistons an cylinders that come with the cam.

I've seriously considered that, but I don't think the 500 jugs cool as well as the 450 and I think they might look dorky with the 450 head. I've got just enough power with what I got and have 450 jugs a plenty. But I agree with your suggestion if one is in a buying mode.

 

[Guest]

You can at least do the cams without disturbing the head though...

 

[sam000lee]

I have the same thing on my GS450 - at idle until the bikes warmed up nicely. It happened on my old engine, too, so I figured it was harmless. That being said I definitely understand finding it irritable!