J33 vs J32 and the cam endplay noise.

[chris900f]

So I bought my low mileage GS500f last fall. I soon discovered that the bike made some sickly sounds after warm-up. I was pretty disappointed
and thought that I was into some major engine work to set it right. Luckily this board had the info on the "cam-walk" noise and that it wasn't a
sign of major engine trouble. Still its a pain and sounds terrible; I'd really like to fix it.

Using the specs from the service manual I found that the 2004 and up bikes in North America all had 5 degrees of timing (btdc) at idle.
This is weird because the same engine used in previous years always had 12 degrees at idle. 5 degrees is extremely low, most bikes run
10-15 degrees.

So the same Suzuki engine used for many years, suddenly developed a problem in 2004 with cam-noise at idle. It was a big enough concern that
Suzuki offered a fix and re-designed the cams for 2006 and up.

Based on this I came up with the working theory that the engines stayed the same and that the very low ignition timing had exacerbated an existing issue.
This low timing was likely a band-aid fix to get the bike past EPA requirements. There is really no other good excuse for it.

The timing is encoded in the ECU. The N/A bikes use the J33 unit with 5 degrees, other markets all seem to get 12 degrees. In Europe and the UK the bikes
get the 12 degree ECU and the cumbersome PAIR valve feeding into the exhaust headers for pollution control.

I decided to test my theory. I bought a J32 ECU from the UK. This is a fairly low-cost fix, around $50.00 and is plug n' play.

The bike starts fine, the ECU still controls the solenoid with the choke on.

It took me a few rides and swapping the ECU's to really see the difference. The J32 really cuts down the cam noise, but doesn't eliminate it entirely.
It was a constant clatter with the J33, with the J32 I get a little clack every 8-10 seconds. If the bike is on the side-stand (slight loading to the left)
the noise disappears.

There is also a small improvement in off-idle throttle. I used to feel a little power "gap" taking off from idle, along with the "chain-y" sound of the
engine running (too) lean. With the J32 installed the bike pulls a little more smoothly from idle and the chain-y sound is slightly reduced. A richer mixture
would solve the problem altogether, but they have done their best to make a simple fix impossible.

I'm still interested in a mechanical fix for the cam-noise, but it may be a while before I can get the parts together and do the work. The J32 ECU improves the
condition enough that it's just a minor annoyance instead of a major headache, and it has some other small benefits that make it a worthwhile upgrade.

[Joolstacho]

Are you getting mixed up with timing figures? I.E. the difference between Static Timing (or advance at tickover revs), and Fully Advanced Timing (advance at high revs).

Various ECU versions may give different Static figures, but that's of little importance because it's the Fully Advanced figures that are important and will be the same (or very close).

Most engines advanced timing tends to be somewhere between 34 to 38 degrees before TDC. And contrary to some misguided belief that better performance can be obtained by more timing advance, in fact, all else being equal a later timing figure can indicate a more efficient, better/quicker combustion process.

[The Buddha]

I didn't read the whole post by chris or jools.
But in 04 suzuki introduced along with a crappily made motor, expensive brightly colored and useless plastic and a carb set that had epa strangled problems they replaced with all new problems with the same epa crap a set of 1.0. 1.1 and 1.2 mm cam end play washers.
So you can get washers to fix the problem they created by sloppy machining that typically doesn't show up in the 89-00 till you hammer out 50K or more miles.
OK My 89 at 45K was pretty loud with only ~.3mm - too thin to fit a washer even at 1 mm.
So open valve cover and look for washer and see if you can put the next washer in.

Cool.
Buddha.

[chris900f]

Are you getting mixed up with timing figures? I.E. the difference between Static Timing (or advance at tickover revs), and Fully Advanced Timing (advance at high revs).

Various ECU versions may give different Static figures, but that's of little importance because it's the Fully Advanced figures that are important and will be the same (or very close).

Most engines advanced timing tends to be somewhere between 34 to 38 degrees before TDC. And contrary to some misguided belief that better performance can be obtained by more timing advance, in fact, all else being equal a later timing figure can indicate a more efficient, better/quicker combustion process.

Nope I'm not mixed up, both ECU's top out at 40 degrees BTDC @ 4000rpm, when I talk about 5 or 12 I'm talking about timing at idle, where the cam-walk noise occurs. 5 degrees at idle is very low and messes with the engines rhythm. The 12 degree figure was what the engine always had until 2004, I believe the engine was designed for that timing, and that the engine didn't change, the timing did, and that the change coincides with the onset of the cam noise issues on the North American bikes. All other markets have the 12 degree (at idle) ECU.

[mr72]

My '92 makes the noise. I never notice it because I never hear it idle once warmed up without my full face helmet on and it's not loud enough to notice.

Point is, it may not be related to ignition timing on the later bikes.

My Bonneville sounds like a bag of seashells and game tokens is sitting on top of the crankcase but I also never notice because my helmet is on. The Triumph guys have a saying: a noisy engine is a happy engine.

[The Buddha]

Ignition advance has nothing to do with cam walking.
Cool.
Buddha.

[chris900f]

My '92 makes the noise. I never notice it because I never hear it idle once warmed up without my full face helmet on and it's not loud enough to notice.

Point is, it may not be related to ignition timing on the later bikes.

My Bonneville sounds like a bag of seashells and game tokens is sitting on top of the crankcase but I also never notice because my helmet is on. The Triumph guys have a saying: a noisy engine is a happy engine.

a) If you can't hear it with your helmet on: it's not "the noise" You can hear this from 50ft away and feel it through the bars sometimes. I came back from a ride and
    had it idling in the driveway, my neighbor from 2 doors down came over to see "what was wrong with it"

b) I never said it was the cause. I said it makes the problem worse. I have both units and there is clearly a difference.

c) I'm not speculating; I'm reporting--see the last sentence in my original post.

So this is a common problem with the 04/05 bikes. I myself have responded to a few posts about engine noise. Once I tell them how to diagnose the cam-walk, the thread ends.
The mechanical fix involves replacing the cams--most people won't do that. A used J32 unit is a cheap and easy way to improve a nasty condition. Even when I do the mechanical fix, I'll keep
the J32 installed.

[The Buddha]

OMG hear it 50 feet away and feel it through the bars

That sounds like counterbalancer bearing or alternator stator to rotor contact or a started clutch lock taking starter for the "ride".

Cool.
Buddha.

[chris900f]

Yikes I hope not, I'm still breaking it in(1182km)...those problems wouldn't be affected by leaning the bike to the left though, which clears it up right away.

I rode about 100km today, the bike is doing much better with the J32: little to no cam noise at stop lights and just a little on re-start of a hot engine after a 10 min. break.

[mr72]

a) If you can't hear it with your helmet on: it's not "the noise" You can hear this from 50ft away and feel it through the bars sometimes.

I don't think we are talking  about the same noise. Thanks cam walk is a subtle "clack-CLACK.....clack-CLACK" at idle. I suspect in the later model problem bikes it's the same sound only louder.

Your problem sounds a lot more like something else entirely. Agree with Buddha. Bottom end.

[The Buddha]

Take off the valve cover, grip the cam sprocket and move it side to side.
If it sounds like that noise just less loud - bingo.
Cam walk even in the most severe cases is that clack clack or tap tap ... nothing alarming sounding at all.

Maybe the geniuses forgot to install the shim/washer.

Maybe they found it was only .9 mm and hence OK to leave out the washer.

Mine at .3 mm it was annoying and a PITA to listen to because it prevented me from hearing important noises if ever there were any. I actually blamed it for not letting me hear my rotor - however I also neglected my loud clack at start (starter clutch going bad) for almost a year when the rotor started disintegrating. The starter clutch is on the back of the rotor, a loud metallic clack means its getting hammered by the slip and grab of the starter clutch obviously.

Cool.
Buddha.

[chris900f]

mr72: "clack-CLACK.....clack-CLACK" that's the sound alright, then intermittently, like 2-3 times per minute a louder CLACK that you can feel though the bars (but it doesn't always do that)

I can see why people think it is a failed tensioner and that the cam-chain is slapping every so-many cycles. It only happens when the bike is fully warmed up, let's just say that if you
heard that sound on a test ride, you wouldn't buy the bike in the first place.

Buddha:
I don't think it's the starter clutch, since there is no issue at start up, but you may have a point about someone forgetting a shim or washer---there is some evidence of sloppy assembly, eg. the bolts on the grab handle had been driven in so hard (air-tool?) that the threads were deformed. Luckily I had some better bolts on hand, but you shouldn't have to chase the threads on the frame if the bolt has never been removed. Also any generic bolt that I remove will be replaced with a better one in the future--they really cheaped out on the fasteners on these things.

At this time I have the J32 ECU installed and the problem has been mitigated to the extent that I feel like I can just ride the bike. Since it is basically NOS, I'll try and source the parts and replace the cams with the newer type with the wave washers when I do the first valve-clearance check.

[The Buddha]

You cant replace cams and this and that and that washer isn't a wave washer.
Its 1mm, 1.1 mm or 1.2 mm option for a single flat washer.

Sorry man, I am beginning to understand less and less about your problem with more of your description.

Cool.
Buddha.

[chris900f]

You cant replace cams and this and that and that washer isn't a wave washer.
Its 1mm, 1.1 mm or 1.2 mm option for a single flat washer.

Sorry man, I am beginning to understand less and less about your problem with more of your description.

Cool.
Buddha.

Sorry that the Suzuki service bulletin pic I posted is so small, but if you squint you can see that there was a factory fix for the 04/05 bikes, they made a replacement cam set with the right ends of the shafts machined to take two 0.7mm flat washers with a wave washer in between. It's also shown in the service manual PDF on page 21-12. Looks like the 2006 and up come that way from the factory.

[The Buddha]

So if its a warranty fix, run over there and get it done.
If you gotta pay for it ... yea these freaking camshafts are several 100 if not more.
Cool.
Buddha.

[Armandorf]

sorry to revive the post, where is located the J32 or J33 identification?
I dont recall from what year is my TCI because i changed it.

Nevermind, found it, it is near the connector

https://i.ebayimg.com/images/g/FNYAAOSwXzBeUAg2/s-l1600.jpg

as i already revived the post, another question i always had, the signal generator rotation mod to advance the timing, is possible with the later model signal generator with only one pickup?