what are the ranges? I lost my notes, and the forum search function is so-so.

https://www.manualslib.com/manual/791753/Suzuki-Gs500-F.html?page=11

If you mean the signal generator. It's about 400 ohms but that link has the range.

I've had good and bad ones test nearly identical when tested outside. On the bike they may have tested different, but they don't spec them for that. Its not a testable component IMHO.
Cool.
Buddha.

That's because heat causes the problem to manifest. That and mYbe even stress from being mounted.

Plus they are not going to be slightly out of spec. When failing they will be either short or open. If a cold part is short or open then it's definitely bad. If it's some amount of resistance between then it's potentially good, might still be bad. You would have to test it hot, which is possible but a pain.

I'm going to put the part in some plastic, and boil some water, and drop it in to heat it up, should allow it to heat up enough to get a change in reading, however when I pass a magnet in front of the point, it jumps to a little over 400Ω  I found that interesting.. does the part need to be powered to get an accurate reading? I have it off the bike currently and just sitting on the bench. I figured no power because i'm just measuring the resistance.

It doesn't have power. It's a passive pickup. It's basically an inductor.

If the resistance is 400 ohms then it's "good", at least when cold. I like your plan to try and heat it up and see if it changes. That should give you a higher confidence that it is good. But you still can't beat running it on the bike for the real test. Eventually with vibration and heat and all that sometimes shorts or cracked windings (open) show up intermittently and there's really nothing you an do besides replace the part as a diagnostic step to rule out a bad coil. This is not a problem unique to motorcycles. I fought this with my Miata for years (crank trigger, camshaft position sensor, and ignition coil packs).

The problem is my GS just decided to stop working in the middle of the road a while back ago now. and I cannot find or explain for why it happened other then bad crank trigger, cause after it was towed home, the next day I got it to fire right up. and i drained the oil, no metal particles, check the oil filter too, both had less then 200 miles on em. both clean. checked the valves, scoped the cylinders. have not compression tested anything but pretty sure it's not inside the cylinder. Wasn't the main fuse either because everything had power.

so using my deduction skills, I can only guess it was the crank trigger, and i checked the connector on the road side that day. can't really think of anything else it would of been but maybe a bad battery.

I agree it's likely the so-called "signal generator".

could be low compression when hot due to valve clearance, depending on the conditions of it dying.

I bet you do your test and find the coil is open-circuit when hot.

Quote from: mr72 on October 10, 2017, 01:50:49 PM
I agree it's likely the so-called "signal generator".

could be low compression when hot due to valve clearance, depending on the conditions of it dying.

I bet you do your test and find the coil is open-circuit when hot.

well the valves are still brand new from a total top-end rebuild. only like 7k miles on em. I think we're right, I'll just have to get time to test and confirm it.

It's just that a hall effect sensor like that will false-positive testing all the time. It's a maddening invitation to waste time and chase your tail. I think pass or fail you should still replace it. That's what I'd do.

BTW I had a receding valve seat on a freshly built head on my Miata ... Every 2-3K I had to open it up and change the shim. It is possible I guess. I mean with only 21K since the valves on my GS were completely shot.

the one that was on the bike, at 70 Degree's C. 455Ω and increased with temperature. BAD.
the one a forum member sent me, that was super janky lookin, at 70 Degree's C. 434Ω BAD.

150 dollars for a brand new one.... *sigh* f k you suzuki, f k you.

So because I was curious, and don't know if there's such resource currently available. maybe someone can compile my data here into something useful, or not.


https://s1.postimg.org/9ig8662lfj/IMAG0499.jpg

the ball of copper wire is weighed in a 4.8 grams, but I sliced a little off when i cut this open [however very little] could be 4.9 grams.

the copper wire thickness is 0.0015 inch, or 0.04mm eyeballed with a feeler gauge and magnification glass. didn't have calipers that could measure that accurately felt that eyeballing it was the best form of measuring I could do.

now I do not have a way to measure the magnets strength. does seem to be a super crap-tastic ferrite magnet.

Quote from: J_Walker on October 11, 2017, 08:59:00 AM
the one that was on the bike, at 70 Degree's C. 455Ω and increased with temperature. BAD.
the one a forum member sent me, that was super janky lookin, at 70 Degree's C. 434Ω BAD.

They will always increase with temperature. Physics says resistance increases with temperature. Provided the coil is copper my math says a 400 ohm (at 25 C) coil will be about 521 ohms at 100C.

They mechanism by which they "go bad" that manifests with temperature is is one of two things:

#1 the wire breaks and has a small fracture that makes contact giving continuity at room temperature, but when the temperature increases everything expands causing the hairline crack in the wire to open up making it open circuit. When it cools it contracts and the wire's broken ends make contact again causing it to begin to work again and test good at room temperature. In this case, the resistance will be some middle value maybe 200-600 ohms when cold and when hot it will be an open circuit (infinity).

#2 the insulation on the wire has an opening in two adjacent wires so they can short, or one wire's insulation is damaged near something grounded like the core. When it's cold the two potentially shorting conductors are kept apart but when heated things expand and push the exposed conductors together causing a short. I think this would be pretty rare, but it still could happen. In this case the resistance will be a middle value 200-600 ohms when cold and when hot it will go way down maybe to zero.

So, as long as they don't go up to infinity or down to zero (or like under 5 ohms) then they are probably fine.

I think both of these potentially good. How much did yours that was on the bike increase with temp? At 100C?

BTW the igniter (ignition module, etc.) is just as likely if not more likely to go bad. And it's way cheaper to replace.

Still I don't know why the aftermarket hasn't supplied GS500 compatible signal generators. They are available aftermarket for dozens of other bikes. This tells me there is no market, which given the number of GS500s on the road tells me they probably don't fail often. I would think the igniter is far more likely to fail, since it's an active part.

ignition module. I have not tested that.. interesting, it would cause both cylinders to stop firing though?

also I cut up the janky-er one because the the part that sticks out was bent. and the magnet fell out an into like 50 different pieces when I took it off the plate. so no loss I still have the original one that was on my bike.

also the link you sent as far as spec. shouldn't that be with the bike warmed up?

the part that was on the bike.

373Ω at 32c
522Ω at 100c

I'm using the 2kΩ setting on my multimeter to get these reading fyi. and I'm no electrical engineer.

Those readings look good to me.

I have no idea what the test procedure is for that part but I would assume that's a bench test, so you test it at room temperature (25C).

IMHO that part is good.

Yeah if the ignition module/igniter was bad then both cylinders would quit.

Basically that "signal generator" part is a pickup made from a coil wound around a pole piece not unlike a guitar pickup. When the little metal protrusion on the plate on the end of the crank spins by it, it creates a little signal, kind of a variation in voltage, just like a guitar pickup does when a guitar string passes by it. The igniter is kind of like a preamplifier. It takes this little signal coming from the signal generator and from that it generates the charge (and causes the discharge) to the ignition coils. If the igniter goes bad, the coils don't charge, so no spark. AFAIK the GS500 is waste spark so both cylinders fire every 360 degrees... one signal from the igniter to both coils. So you won't get one side good and the other bad if you have a bad igniter.

I've never had to deal with the ignition module here, so whats the testing route for it?

I don't know. Maybe the FSM has a method of testing it. If I had to imagine a way to test it, I think it'd require an oscilloscope and a function/signal generator, or just probe the output while cranking the bike, view output on a scope.

But you don't have an oscilloscope, so I think I'd identify that part is bad by process of elimination. Test everything else, it has to be that.

Maybe someone else knows the right way to do it.

well because of reasons ill test everything else I can. but for now I just ordered a new battery. my gaskets and clutch plates.

for anyone who's lurking now or in the future and goes "what battery was it?!"
https://www.batterystuff.com/powersports-batteries/sYT10L-A2.html


He's a run down of what happened that day it died..

I was riding around for 30 minutes.
I was riding down the highway at probably 5th gear 7000RPM.
Came to a section of highway where it has stop lights.
There was this beater car in front of me blowing all kinds of smoke and I was choking on it. so when the light turned green I opened up the throttle and went to go around him.
when I was besides him, I instantly felt a loss of power, like I was down 1 cylinder and it was chugging pretty hard.
[engine is HOT because of highway moving and florida mid day 90s heat.]
I reached down and over at the next light pressing the sparkplug boots down.
I made the decision to turn around and head back home an try to limp the bike.
It then started making a loud tapping sound, I think this was cylinder pinging. I now felt that If the RPMs dropped below 5000RPM it was gonna shut off and god knows if it was gonna start back up, but I needed to hit a gas station first so I risked it and made it to a gas station, filled it up [was kinda low] and it started up just fine, but I had sat there for sometime talking with a homeless dude [about 30 minutes]
Got back on the bike and headed up the road, two stop lights later it felt REALLY down on power and I knew if I let the RPM's get low It was gonna stop. but holding 5kRPM@ a stoplight thats like 2 minutes long. on an air cooled engine wasn't gonna work, so I let them fall and it stopped, and it wasn't coming back on.
I push rolled it in neutral through the turn light and got into a empty parking lot, checked all the usual GS connectors that could cause issue. everything connected, when I hit the starter it wouldn't turn, it made a metallic click like it was hitting something solid. BUT not the clicking noise of a starter relay and a flat battery.
So I thought I'd bump start it, threw it in 2nd gear pulled in the clutch, and tried started rolling forward, 4 times. the rear wheel was just frozen and slid across the pavement. at this point I'm thinking "yeah the engine is seized" and got a tow truck and had it towed home.

Next day its been sitting in my garage. I go out there thinking the engines seized, figured "meh" before I drain my tank I'll try starting it one more time... so I took off the side cover, and "forced" it to turn over with a B.A.W. [big arse wrench] after it felt free'd up. I decided to hit the starter. an sure as sh t started right up no issue, and no really loud weird sound. so I shut it off after like 6 seconds an think "hmmmpf" maybe it's the crank pickup/trigger?

then I proceeded to drain the oil, and check for flakes [oil had less then 50 miles on it and was heavier motorcycle oil!] No flakes,no visible damage, all valves seemed to be sealing and not bent. [I did a light check at night] and scoped the inside of the cylinders no walls looked marred. took off the crank case cover to check for the GOATs all was good, took off the other side... everything looked good, I'm at this point looking for why the damn engine was frozen and not turning over. so pulled the clutch plates, and they where GONE. pretty much so I thought well maybe because of them being so warn they got stuck together some how.. and weren't freeing up. I stopped there on the mechanical side and switched over to looking at the electronics and testing them all.. then it proceeded to sit for weeks.. mostly apart because I'm stumped as to what it could be. lol