Fix the cam float problem or get another head?

[ddaniels]

If I had that problem, which I suspect I do, what would cost more, to do the fix that has been posted as far as machining out the cam caps and inserting a half moon spacer, or looking for another head and cams without the problem? Talking about an '81 1000G.

 

[TheCafeKid]

Dave, my 1000 has the same problem. Honestly it's not something that's going to do any harm, and I know it, but I must admit that sound just makes me cringe. I've even adjusted the idle up to about 1200-1300 just so it's less even though I know that's a little fast on idle speed. I don't know that I'm honestly going to do anything about it, but I'll be interested to see what the hive mind thinks. AFAIK as I understood it, it's the bearing caps themselves that wear, so you may get away with new/uses bearing caps... I dunno.

 

[Nessism]

What does the noise sound like? Is it a tic type noise, knock, or what? And what frequency? Consistent with rpm, random, ?

 

[TheCafeKid]

What does the noise sound like? Is it a tic type noise, knock, or what? And what frequency? Consistent with rpm, random, ?

Mine is def cam walk.. Sounds like a tapping with kind of a walking whisper and once you give it throttle atall it goes away... I have t hears dave's yet but by his previous descriptions in other threads I'm guessing it's the same thing...

 

[SqDancerLynn1]

ANY GS head is going to have some cam end float. If it bothers you the best aproch is to do the Modification. Or just live with it as a normal GS noise

 

[ddaniels]

The first GS1000G I owned did not have the problem, nor did it make any kind of unusual noise at all. And it was the same year bike as this one. I can't say for sure that I have that problem. When it's idling, you don't really hear ticking but you hear definite pulses like daga daga daga daga daga....etc instead of a nice even, steady purr, which my first G had. The ticking happens when you give it throttle under a load. If I give it throttle just sitting in the garage, the ticking is not really noticeable so much. But when I take off down the road, the ticking is really loud until it gets up in rpm's. I've discoverd if I don't shift until it's around 3800 rpm's or higher, the ticking is less noticeable. The bike runs really well and the ticking doesn't seem to have any impact on that, but it really is annoying to listen to. First thing I did was a valve adjustment thinking that was the problem, but it had no effect whatsoever. I also put in a manual tensioner but that had not effect either.

Josh, after reading the pdf on the fix, I understood that what wears is the bearing surface of the cam that butts up against the bearing surface of the head....or maybe the bearing surface of the head is what wears, which is more likely since the cam is probably hardened. Anyway, I'm going to do some more research on the subject and for now, just listen to the clock tick.

 

[tkent02]

I was thinking of making some nylon "buttons" to take the place of the half moons, that reach in just enough to almost touch the ends of the cams, to keep them centered.
Any one have the machining ability/equipment to make a few of these?

 

[Dogma]

That sort of capacity is on my to-do list, but it's a couple years out. Is Nylon the best choice for that? What are the cam chain guides made of?

If you want to pursue this, you might find someone willing to work with you over at CNCzone. IIRC, they have a forum for people looking to do side work.

 

[srsupertrap]

What does the noise sound like? Is it a tic type noise, knock, or what? And what frequency? Consistent with rpm, random, ?

My cam end float noise was a knock, pretty loud at idle and disappears at 2000 rpm. If you are not a Machinist or have a Machinist friend you probably should find a low mileage cylinder head and swap them out. You have to make very accurate measurements to get it right. The half moon spacers can be made from bronze or aluminum like the article specifies. Nylon 6/6 or delrin would not last.

 

[ddaniels]

You could probably get away with using UHWMPE (ultra high weight molecular poyethylene). Very tough stuff with a low coeficient of friction.

I don't personally know a good machinist but there are some places I know of where I could go. But the price for just a few pieces would be very high. And, I'm not a machinist myself, or have any equipment. That's why I was considering trying to find another head/cams. But that option would probably be time consuming. Still not sure that this is my bike's problem yet either.

 

[BadBillyB]

I dont believe you are hearing cam end float knock. This would be typically only heard at idle. My first GS1000 (1979) had the noise right away when new. The noise was only heard on a fully warmed up engine at curb idle. If you slightly raised the idle the noise was gone. The Suzuki dealer I bought it from kept it for days and never found out what it was. I found it myself a year later when installing aftermarket cams......The best way to describe the sound is like a tapping, knocking noise that is very rythmic and went back and forth between barely audible to fairly loud on its own, without touching the throttle......If your noise is under load, I dought that it is cam walk.......Billy

 

[jhillier449]

I use a lathe and CNC machine at work. if someone can give me some dimensions or a drawing of some sort, I would like to give it a go if someone can come up with a suitable material. Perhaps nylon or teflon will work?

Cheers

John

 

[north49]

D daniels..........just my two cents worth here. My '80 GS1000 needs the cam mod and I've been reading the maching reqirements pretty carefully. I don't know yet if I / you / we can measure the cam end float without taking the head off. If we can measure the end float then just remove the cam caps for machining, then I reckon a machinist could do the required work in a couple of hours. Maybe $200. If you have to remove the head , then maybe getting another would be feasable. But you never know what you're buying. Seems like a better plan to keep your head and get the caps machined. If some entrepreureal machinist member of this group wanted to start making these mods then that could be good. If you could accurately measure the cam journal and the end float, then you could just send the end caps for machining.

 

[ddaniels]

Plus you'd have to make the spacers as well.

After reading BadBillyB's post describing his cam walk problem, that's not at all what mine is doing really. I guess the best way to describe it is that it kind of sounds like dieseling because it ticks (knocks) at low rpm's while getting on the trottle. As soon as the RPM's are hight enough (around 3800) the ticking quiets down. What else could it be?

 

[Suzuki_Don]

I agree with Billy. I don't think you have this problem. I definitely do have this problem. When I start my bike on full choke then turn the choke off after a few minutes and the motor settles down to a good idle, there is no noise coming from the motor whatsoever. But after the motor is fully warmed up there is this knocking/rattling sound coming from the top end at idle, anything above 1500rpm and the noise disappears, with my motor it is more from the exhaust camshaft than the inlet cam.

This no noise when cold and much noise when warmed up is the symptom to look for. If you don't have this then you don't have cam creep.

I have a thread running on the same issue as I did not see this thread until just now. And I want to know if there is any way to measure the end float of the cams without removing the head.

I know this ailment will not hurt the motor, but it's BLOODY EMBARRASSING when the motor is idling.

 

[north49]

Suzuki Don...re: measuring the end float with removing the head. When you remove the valve cover, you'll see one valve being depressed. You need to have the cam shaft laying in the journals to measure the end float. I haven't tried this (yet) but I reckon if you removed the shim and tappet from the depressed valve, the cam may then have enough clearance to lay down in the journal.
I hope this works 'cause I don't want to pull the head to do this otherwise pretty neat and easy job.
I'm busy with other projects right now so hope you try this out and let me / us know the results

 

[TheCafeKid]

I like Tom's idea of nylon or some type of "wear-resistant" polymer to replace the stock half moon cam plugs... Even if they didnt run in all the way to TOUCH the cams at all times, it would at least lessen the amount of the walk. I flipped my stock rubber moons backwards, and its seemed to help a little.. Still there.. tho my bike actually makes the noise more when its on a cold idle than after its hot... chuff chuff chufflle..... chuff chuff chuffle...

Lets all do
the cam walk shuffle

 

[BadBillyB]

Plus you'd have to make the spacers as well.

After reading BadBillyB's post describing his cam walk problem, that's not at all what mine is doing really. I guess the best way to describe it is that it kind of sounds like dieseling because it ticks (knocks) at low rpm's while getting on the trottle. As soon as the RPM's are hight enough (around 3800) the ticking quiets down. What else could it be?

This is a symptom of excessive ignition timing advance. Check your timing. Also carefully inspect your timing advance mechanism for binding. It should rotate by hand counter-clockwise with some effort (spring loaded) and snap back when you let go of it. Check the springs on the back for stretch. If all looks OK, try retarding the timing and see if the noise goes away. This will tell you if you are on the right track. Is it possible the top of the pistons are all carboned up ???.....Theres a remedy for that too......Billy

 

[ddaniels]

I'm pretty darn sure the tops of the pistons are carboned up. From the looks of the valves they have to be. I'll check into the timing too. Thanks for the tips.

 

[Dogma]

Reading this with interest, as I have the same symptoms.