2006 GS500, about 26k miles.
Runs well for about 10 minutes then stalls suddenly. I try restarting and the starter motor sounds fine but it won't turn over. Pull the plug and no spark. Let it sit for 30-60 minutes and starts right back up.
Just replaced the battery, spark plugs and ignition coils and still the same. Not sure where to go from here...
(Continuation of a previous thread here: http://gstwins.com/gsboard/index.php?topic=70532.0)
Testing the voltage between the battery positive terminal and the engine block shows it hover around 12.6v before the reading starts bouncing around. I get a good reading between the battery terminals.
I'm not very mechanically inclined and I'm trying to find my Haynes manual. Where are the fuses located on this bike?
There's only one fuse (and a spare fuse) on the bike. So if anything else electric works, it's not a fuse problem.
You've replaced the coils? With what? Like I said earlier, newer oem coils are usually good for a long time. I don't know what else could overheat..... have you inspected the wires from the signal generator on the right side of the crank and followed them up to the black box?
Have you checked your valve clearances recently? Over time valve clearance reduces until the valves will barely close. When the engine is hot the valves get longer due to thermal expansion making it so that the valves do not close at all and the engine loses compression.
This is probably why you are able to restart the engine after letting it cool off for a bit.
If your valves are out of spec when you get them fixed up you will notice a dramatic improvement in the way the engine warms, idles, and runs.
Thanks guys. The valve clearances definitely need to be checked soon. But I'm definitely not getting spark post-stall, so there's some issue in the ignition circuit. I am getting spark after it cools down.
Really strange. I'm worried about the readings I'm getting between the battery's positive terminal and frame/engine housing. It seems like a poor ground might cause an issue like this?
Do you know where the ground connection coming off the negative terminal is supposed to be?
Rich: I replaced the coils with newer OEM ones. It was cheap to rule out and I had read about others with similar symptoms leading back to the coils. :dunno_black:
I'm almost positive the ground wire goes from the battery to the rear of the engine. When you get that 12.6v reading between the frame and battery, what are you getting straight across the battery terminals? If its only 12.7v, I wouldn't worry too much.
I'm getting just under 12.7 across both terminals, but the reading jumps around between + terminal and engine frame. Maybe bad connection, or my multimeter isn't working. I'll try finding that ground connection in the morning, and see if shorting the - term to the frame makes any difference with the voltage reading.
Signal generator coil developing an open circuit when warm and rectifying itself as it cools.
You can either.....substitute the part with a known good one and see if the problem disappears....or....take some readings across the coil when cold and another as soon as the bike cuts out....or.....take the parts off the bike, take some static resistance readings, warm them in an oven, take another set of readings and compare them.
Another trick, something I have read about but never tried is to hit the coil with a blast of compressed air as soon as the bike dies, the idea being to cool it. Then see if it restarts.
You wouldn't be the first to suffer this problem, its been mentioned many times in here.
Quote from: lucas on May 20, 2016, 10:14:47 PM
Have you checked your valve clearances recently? Over time valve clearance reduces until the valves will barely close. When the engine is hot the valves get longer due to thermal expansion making it so that the valves do not close at all and the engine loses compression................................
Valve clearances
increase as the engine warms. Steel valves expand but aluminum head expands more lifting cams away from the buckets.
+1 to Sledge post. It acts like a bad coil so if it isn't an ignition coil it's probably the pickup coil. Only one pickup coil on your F model.
That makes sense since aluminum expands more than steel. So I guess tight valve problems tend to make bikes stall when cold but not after it warms up?
I'm getting 4-5 ohms from the disconnected negative lead to engine housing near the spark plug. That can't be right, can it?
Here's the negative terminal lead:
https://imgur.com/a/zIDSd
I have no idea how I'd clean the connection in that second picture without replacing it.
Does anyone know where the chassis/engine ground connection coming from the battery's negative terminal is (2006 500F)? Nothing in Haynes that I can find about it.
So I naturally misread my ohmmeter at first so nevermind about all the bad ground stuff.
But it looks like sledge got it with the pulse generator coil. Tested in range before ride, now has extremely high resistance after it stalls. +1
Based on the location of the coil, I guess it's likely to overheat again if I replace it. Possible too that I damaged it from running for several hours a quart low on oil...
Out of curiosity how did you test it after it stopped? I have not really done any electrical testing before but have a similar problem to you after long rides.
I was going off the Haynes manual. For later models: "Trace the pulse generator coil wiring back from the right-hand side crankcase cover and disconnect it at the 3-pin connector. Using a multimeter set to the ohms x 100 scale, measure the resistance between the brown and black/blue wires on the coil side of the connector." I didn't disconnect, just measured from the back of the connector. Looking for 250 to 420 ohms. For me, the connector was a little forward and left of the rear wheelwell.
Ok cheers
Jimbob, not sure what model/year you have, but you should see a white three-pin connector on the left side (accessible if you remove the seat and aft the battery) that looks like http://i.ebayimg.com/images/i/131260089529-0-1/s-l1000.jpg which is plugged into a black connector. Shove some multimeter pins into the brown and black/blue wire connections.
does it matter which pin i put the black/red pins of the multi meter and did you unplug the battery first? Also mine is an 04
It doesn't matter. Just keep in mind that you'll likely get a good reading like I did when it's cold so you'll probably have to wait to test until it stalls again.
Ok thanks for your help
I'm glad you got this figured out. I also had ignition coil or its wiring go bad and its the most annoying thing. Hard to diagnose as well.
Thanks. I suspect it's running very hot (or was running hot for lack of oil) and it burnt out. A little nervous to stick a new one in until I can figure out why it's running so lean/hot. We'll see if the valve clearances are in spec.
I wouldn't worry about re-damaging the replacement too much. The ignition pickup seems to be a fairly common electrical failure on these bikes. I replaced mine at 22,000 and I'm now at 37,000 miles and have never given it a second thought. If I recall, they are also not too expensive to pick up second hand.
That's reassuring... it was running about a quart low for a few hours and guessing the extra heat might have damaged it too. Was lucky to find one on ebay for $50.
" I try restarting and the starter motor sounds fine but it won't turn over."
to me that sounds like the startor clutch is slipping, does the engine crank normaly or do you just hear the startor motor spinning?
Smokestack is this the part you replaced?
http://www.ebay.com/itm/2005-Suzuki-GS500F-GS-500-F-04-09-Engine-Motor-Signal-Generator-OEM-Original-/391224858592?hash=item5b16d197e0:g:YZ8AAOSwHnFVzNP2&vxp=mtr
Yeah, that's the one that tested bad last time it stalled. I won't have the part until tomorrow but I'll report back once it's installed
Quote from: jeZZa on May 24, 2016, 02:08:34 PM
" I try restarting and the starter motor sounds fine but it won't turn over."
to me that sounds like the startor clutch is slipping, does the engine crank normaly or do you just hear the startor motor spinning?
I think I misused "turn over", I meant to say that it cranks but won't start. Starter motor sounds fine.
The signal generator coil fixed it.
The bike is still running very hot, practically cleaned off the spark plugs in 30 miles.
It's also developed this ticking sound that's consistent with engine RPM. It's inaudible when cold and gets louder as it heats up. Just put in non-synthetic 10W-40. The valve clearances are in spec with the exception of the left exhaust valve which is a bit less than .03mm (the lower bound). The cam chain was looser in places than others. The tightest lengths had almost no play, and the looser ones maybe 15mm but I didn't measure.
It also starts idling high, around 3.5k, after it warms up.
If this is all a function of heat I'll just rejet.
Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?
The stock jet sizes are on right now (17.5/60/130), stock exhaust and OEM filter in the airbox. My scientific wild-ass guess is to go to 20/65/140 and hope it cools down. The plugs look almost brand new after running it for 30 miles.
Quote from: smokestack on May 29, 2016, 07:06:06 AM
Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?
The stock jet sizes are on right now (17.5/60/130), stock exhaust and OEM filter in the airbox. My scientific wild-ass guess is to go to 20/65/140 and hope it cools down. The plugs look almost brand new after running it for 30 miles.
I went 20/60/132.5 with a shock bike, I think your good but the 140 is probably a bit Fat for a stock bike :dunno_black:
Quote from: smokestack on May 29, 2016, 07:06:06 AM
Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?
No, each circuit overlaps each other. It sounds silly, but true. Now, if you take out your main jets altogether it will still idle, but not the way it should. Have a look at these first couple charts for an idea:
https://www.google.com/search?q=carb+jetting+chart&hl=en-US&source=univ&prmd=isvn&tbm=isch&tbo=u&fir=qI5QQmUYVCzI-M%253A%252CG1Xg3ZjarfjPqM%252C_%253B8B4W6IrIb4ECvM%253A%252Ck8KG-spHl4lJ9M%252C_%253BwkaQKTuusOHYIM%253A%252CzOiN5F3S9STo-M%252C_%253BqJbvwhCLo4j1VM%253A%252CAU3kjvUtdqZnSM%252C_%253BYj3GiNRvuezINM%253A%252CJIIuIzU6383hVM%252C_%253BYZXkHmqfKq_EuM%253A%252CIKWN8Q3NlfM0aM%252C_%253BPdE8yNqK86cpNM%253A%252C4_CcGwWHohHZfM%252C_%253BgdLbIJ5ZP4z6JM%253A%252CrKpTn0MBbSfQEM%252C_%253B8PLpIHoFtCPW9M%253A%252CrKpTn0MBbSfQEM%252C_%253BV_XZmb7EO_IKWM%253A%252CIqJ8Phy3wUKCaM%252C_&usg=__-cfjqkdHEwfkZs7F4l0oiji0WPM%3D&sa=X&ved=0ahUKEwjJw6rZzP_MAhVHTFIKHbclBXYQ7AkIIg&biw=360&bih=615&dpr=4
Quote from: Suzuki Stevo on May 29, 2016, 07:44:52 AM
I went 20/60/132.5 with a shock bike, I think your good but the 140 is probably a bit Fat for a stock bike :dunno_black:
Yeah, I was thinking better to err on the side of too rich and throw on a different filter if it's too much.
Quote from: Big Rich on May 29, 2016, 08:29:56 AM
No, each circuit overlaps each other. It sounds silly, but true.
Got it, thanks.
I'm looking on Jetsrus.com and they only seem to sell mains and pilots, but not mid-mains? The wiki says that the mains and mid-mains are the same part number but they're definitely different sizes on my carbs. Do the physical dimensions scale down with the jet size?
Sorry, this is the jetsrus.com page I was referring to: http://jetsrus.com/a_jet_kit_street/suzuki_500_GS500F.htm
If you pull the carbs and look at the jets, you'll see the factory 60 & 130 jets look the same on the outside, but the inside diameter is different.
Might be overly simplified, but that's how they appear to my eyes.
Yeah, all three appear to be different sizes to me too. I can't find anyone on the web (Z1, BikeBandit, Jetsrus) that sells a "mid-main", or anything other than a main and a pilot.
Part 27 (Jet, Main 60), and part 16 (Jet, Main 130) both have the word "main" in the Suzuki parts fiche. I assume this is because they are both technically Main jets of different internal aperture sizes. (I'm not a carb expert by any means.) Part 26 is the 17.5 pilot jet listed on the fiche. Again, specifically listed as "pilot" jet. Given the overall function of each jet, it seems appropriate for the mid-main to just be a small internal aperture main jet.
My naivete is causing a lot of problems. The main jet was screwed into a much larger jet-looking thing that fits over the needle (the needle jet?) and looked like a single piece. Managed to separate the two with a small spacer and flat head. It is the same size as the mid-main. Back in business for now.
Sorry for the confusion... thanks for the help jdoorn :)
Buddha is a good jets info source also!
You mean the enlightened one? I hope he's listening..
I'm sure Buddha is listening. Holiday weekend and all usually means people get a bit scarce for a couple days.
BTW, the only place I've ever found any reference to a "mid-main" relative to the GS500 is here in this forum. It's likely spawned from the difference between the 2 circuit and 3 circuit carbs as a way to explain the functions. I was confused myself until I pulled the carbs to clean the bowls/jets on my '07 and referenced the parts fiche a few times just to know what I was looking at.
Also, the parts fiche isn't always to scale. They're more concerned with relative location and assembly than scale. The 60 & 130 are basically the same size in your hand, but the parts fiche shows one of them (I think the 60) to be a lot smaller than the other.
Buddha's shipping me some jets today, excited to get this back on the road. Stevo, I took your advice and asked for smaller jets, he suggested I just go to your setup, 20/60/132.5. I might have an air leak somewhere that's leaning it up more than normal anyway.
That's good to know about the parts 'fiche jdoorn. I was trying to piece together old forum posts and pictures, also confusing since the earlier models only have the two jets.
This bike is making me work for it.
I've rejetted twice now:
Stock: 17.5/60/130 - very lean, white plugs
First rejet: 20/62.5/132.5 - can't rev past ~5k RPM or get over 30mph, engine just bogs down
Second rejet: 20/60/130 - no noticeable difference, still bogs down at 1/3-1/2 throttle, dies on cold start with full choke but runs fine cold without the choke. Before, it would need full choke for 3-5 minutes or it would die.
I can see the choke slide on the carbs closing all the way so I don't think the cable got over tensioned (I didn't adjust it anyway). The pilot air screws are out three turns (more turns = more rich?). Float height is about 14mm.
All I did was switch out the jets and adjust the pilot air screws.
Would a small step up in the jet size really affect the mixture that much? Is there something else I could have botched?
I'm just remembering that I took off the Throttle Position Sensor the first time and just reattached it when I was done. Trying to search around on how I could have screwed that up.
Yeah, I bet the TPS was mounted incorrectly. Had no idea the alignment mattered.
If I completely disconnect the TPS, it runs the same. When I hold the throttle all the way open though, it blips to 3k RPM every second and returns to idle. Cool.
Adjusted the TPS per the Haynes manual and still getting the same thing:
Dies cold with full choke, idles fine without choke but can't rev past 6k RPM or it dies.
20/60/130, 3 turns out on the screws. Started happening after swapping in a 20 pilot jet (replacing a 17.5 jet)
Can't believe the new pilot would rich it out that much... I guess I'll fiddle with the air screws but is there anything else I could have done wrong?