Well thanks - sounds like you had very similar symptoms for sure. I'll try and give it a shot tomorrow hopefully.
Mystery problem with starter switch
- Thread starter claytonia
- Start date
ChriSTian_64
Site Supporter
Something that comes to my mind, in reference to the new spark plugs that got black quickly on the right side... I think, if I remember correctly, that when the small rubber diaphragm of the... is it the fuel cut off valve (?) breaks with age, then, I think it is the right cylinders that gets a bit fouled with fuel, and can cause misfiring, intermittent loose of power and your spark plugs get dark on the right side.
Or is it only on cylinder number one (front left) ? Someone will correct me.
I have ordered a fuel cut off valve diaphragm replacement kit (about $12 on amazon) last year, mostly as a preventive measure for my 21 tears old ST1100.
I still have to install it, as so many other parts ordered (Horns, Led Headlights, progressive springs for the forks, stem valves, new tire, etc).
Clay, I saw the new label you created for your new fuse box. Very well done. I'm just curious... why did you label one fuse : "Idiots light horn" ?
Or is it only on cylinder number one (front left) ? Someone will correct me.
I have ordered a fuel cut off valve diaphragm replacement kit (about $12 on amazon) last year, mostly as a preventive measure for my 21 tears old ST1100.
I still have to install it, as so many other parts ordered (Horns, Led Headlights, progressive springs for the forks, stem valves, new tire, etc).
Clay, I saw the new label you created for your new fuse box. Very well done. I'm just curious... why did you label one fuse : "Idiots light horn" ?
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It is the rear right, cylinder #3, but only that one cylinder would be affected.
since it appears to be both cylinders on the same side, I'm in agreement with the previous suggestions that the ignition coil and its connections would be the primary suspect.
Those are the circuits for that fuse, and I only had so much room. I forget what the original label said, but this was clearer to me - the idiot (warning) lights above the instruments, plus the horn. And I checked the rubber parts in the petcock and they looked pretty much perfect.Something that comes to my mind, in reference to the new spark plugs that got black quickly on the right side... I think, if I remember correctly, that when the small rubber diaphragm of the... is it the fuel cut off valve (?) breaks with age, then, I think it is the right cylinders that gets a bit fouled with fuel, and can cause misfiring, intermittent loose of power and your spark plugs get dark on the right side.
Or is it only on cylinder number one (front left) ? Someone will correct me.
I have ordered a fuel cut off valve diaphragm replacement kit (about $12 on amazon) last year, mostly as a preventive measure for my 21 tears old ST1100.
I still have to install it, as so many other parts ordered (Horns, Led Headlights, progressive springs for the forks, stem valves, new tire, etc).
Clay, I saw the new label you created for your new fuse box. Very well done. I'm just curious... why did you label one fuse : "Idiots light horn" ?
OK so I first swapped the coils, which seemed to make things even worse. It was running so poorly that I couldn't take it out - even when warmed up, it wouldn't rev above 4k unless I added choke. And all the plugs looked pretty wet (although all were getting spark). Also bypassed the fuel petcock, which made no difference (see above reply). And then the battery was dying. Too weak to turn over, I charged it back up with my Battery Tender, which brought it up but to slightly under 10VDC. My battery/charging tool said to replace it. So I have a new one coming on Mon. (glad to see Lithium batteries are getting more reasonable). I have no idea if this was related to the initial problem or not, but it certainly wasn't helping things. I'll post an update Mon. or Tues.
Thanks again for all the advice, comments, support!
Thanks again for all the advice, comments, support!
Uncle Phil
Site Supporter
Does it have the OEM fuel pump in it? It sounds like either the carbs are flooding now (from too much fuel pressure) or the coils are really weak.
Keep plugging - you will get it sorted!
Keep plugging - you will get it sorted!
Thanks Phil. Pretty sure it's OEM - this bike has less than 40k on it. I'll see if the battery helps. My instinct is that it's electrical, because it never had anything remotely like this issue prior to replacing the fuse box and doing the red wire bypass. Keeping my fingers crossed...I used to find it therapeutic to work on my bikes - now it's just annoying and taking away from riding time!
OK so it's still running REALLY poorly - I'm guessing only 2 cylinders are firing, as it's extremely sluggish to respond, and I can't get it much past 4k rpm (and that's with some choke - without it's even worse).
I have started checking my charging with a meter, as the battery dying was kind of a mystery. So with the new lithium battery, fully charged, I get these readings:
Ignition off: 13.30v
Ignition on: 12.77v (after :30, as it drops steadily for the first few seconds)
Running @2k to 4k rpm: 12.67
After 1 min. @shutdown -
Ignition off: 13.30v
Ignition on: 12.73v (after :30)
All the plugs are getting fairly uniform spark. I'm going to try running it for maybe 10 minutes to see if I can get some sort of plug reading. I really feel like (1) this problem should somehow be related to the work I did when fixing the starting problem (since it was running great before that - could a poor spade connection to/from the fuse box cause this?), (2) would these voltage readings be indicative of a problem in that area significant enough to cause the symptoms I've described?, and (3) I must be missing something REALLY obvious because it's just running so poorly.
I have started checking my charging with a meter, as the battery dying was kind of a mystery. So with the new lithium battery, fully charged, I get these readings:
Ignition off: 13.30v
Ignition on: 12.77v (after :30, as it drops steadily for the first few seconds)
Running @2k to 4k rpm: 12.67
After 1 min. @shutdown -
Ignition off: 13.30v
Ignition on: 12.73v (after :30)
All the plugs are getting fairly uniform spark. I'm going to try running it for maybe 10 minutes to see if I can get some sort of plug reading. I really feel like (1) this problem should somehow be related to the work I did when fixing the starting problem (since it was running great before that - could a poor spade connection to/from the fuse box cause this?), (2) would these voltage readings be indicative of a problem in that area significant enough to cause the symptoms I've described?, and (3) I must be missing something REALLY obvious because it's just running so poorly.
Slydynbye
Will ride for Pie
That Right there tells me the charging system isn't right. You should see about 14 Volts when running
Probably what killed the first Battery.
Yeah I know, I agree. Prior to all this mess that's what I was seeing on my plug-in volt meter while running. What I'm trying to figure out, and maybe someone can explain this, is how this weakness in the charging system could cause it to run on two cylinders. Unless it's just a coincidence. Or could that have somehow damaged the coils? Electrical systems have always been an area of weakness for me.
Hope to get to all of the suggested alternator and related wiring inspections and tests tomorrow. I realize a new alternator is likely in my future here.
Hope to get to all of the suggested alternator and related wiring inspections and tests tomorrow. I realize a new alternator is likely in my future here.
Slydynbye
Will ride for Pie
It could be a regulator which is external to the Alternator.
I think the Kiss of death on the early alternators was if they leaked, so there's Hope as long as it's not leaking..
Remember that replacing parts is a terrible way to troubleshoot.
The sparks being equal and the choke "helping" suggest fuel issues now.
On a 30 year old bike its not too much a stretch to believe that two different systems experienced failures at around the same time just by coincidence.
Was your plug-in volt meter giving these low readings before you did the red wire bypass and other electrical work? If so, then that would explain the previous dead battery. It shouldn't have anything to do with the coils, but given that they're 30 years old its not like they're going to last forever either.
Just to make sure, are the voltages you posted earlier at the battery terminals, or somewhere else?
Basically, a bike with a dead alternator is unridable anyway, so if that's really the case then that would be priority one. Depending on how badly you want to keep this particular bike you have to decide if the expense and hassle of replacing/repairing the alternator is worth the investment given that the bike may still run like crap and require more troubleshooting and expense later.
there's a chance it will start running better with a 14V+ alternator output, but no guarantee, ignition systems are very finicky.
Thanks! To answer your questions, the plug-in meter wasn't on the bike before I did the red wire bypass, but before this poor running problem I was getting good readings (despite it not being wired directly to the battery), maybe around 13V static, 14+V running at speed. And yes, my current multi-meter readings were direct at the battery.
I am fairly committed to the bike - despite it's age, I really like the way it runs, comfort is great, it's still fairly fun to ride, and aesthetically I love it, and the finish is just about perfect overall.
Having said that, after fixing the starting problem and then this issue crops up, I was thinking of a nice Yamaha FJR1300 or something similar, and newer. Working on my bikes is just getting to be no fun (see my list) - besides the ST, my restored Bultaco refuses to start (it was fine a few months ago) despite having good spark and fuel delivery (I means it's a two-stroke, electronic ignition, what the hell could have changed? I'm guessing the timing must have drifted), and my Yamaha 650 is missing at higher revs like the ST (pretty sure it's time to clean the carbs - thanks to the ethanol gas). But then my Suzuki is fine, the KLR is reliable, and the new Tenere is still like new, so I can't complain there.
Yeah, so I took a little longer to get to the alternator tests than planned. Been avoiding the bike - getting pretty frustrated, plus pretty hot in the garage lately.
Only did the static ones, but it appears to be OK in that regard:
3P Red Connector: all yellow to yellow ~.4 ohms; none connect to ground
2P Black Connector: mine has a white and black wire, no red one (so I'm assuming the black=red...?) - hard to tell if I'm making contact down inside the socket, but those test seemed OK (yellow to white and black both no cont.; unsure about black to white - hard to get both probes down in there)
So not totally confident in all those tests, but the alternator isn't leaking. Would it make sense to replace the regulator now? New go for ~$40 ($30 from China - I'm guessing they're all made there) on eBay (are those likely junk?). Anyone have any suggestions (should I replace it, and where to get one that isn't junk)?
It still starts up easily, but really sounds and feels like half the cylinders are on the job. If I put my hand over the rubber intake tubes to try and choke individual cylinders, it seems like the right bank (#2 & 4) is the culprit. Pulled the plugs this AM, after running for maybe 5 minutes last weekend - not surprisingly (these are brand new NGK Iridiums) they all have next to no buildup on their tips, and all but #2 are a bit wet.
Can someone tell me, could the running issues be due to the weak charging output? I feel like I have two new but apparently unrelated problems here. But maybe there's a connection I've missed.
Only did the static ones, but it appears to be OK in that regard:
3P Red Connector: all yellow to yellow ~.4 ohms; none connect to ground
2P Black Connector: mine has a white and black wire, no red one (so I'm assuming the black=red...?) - hard to tell if I'm making contact down inside the socket, but those test seemed OK (yellow to white and black both no cont.; unsure about black to white - hard to get both probes down in there)
So not totally confident in all those tests, but the alternator isn't leaking. Would it make sense to replace the regulator now? New go for ~$40 ($30 from China - I'm guessing they're all made there) on eBay (are those likely junk?). Anyone have any suggestions (should I replace it, and where to get one that isn't junk)?
It still starts up easily, but really sounds and feels like half the cylinders are on the job. If I put my hand over the rubber intake tubes to try and choke individual cylinders, it seems like the right bank (#2 & 4) is the culprit. Pulled the plugs this AM, after running for maybe 5 minutes last weekend - not surprisingly (these are brand new NGK Iridiums) they all have next to no buildup on their tips, and all but #2 are a bit wet.
Can someone tell me, could the running issues be due to the weak charging output? I feel like I have two new but apparently unrelated problems here. But maybe there's a connection I've missed.
Still getting nowhere. Tried two more things:
1) Did a suggested test of the alternator output - checking for 24VDC (?), while running, from each of the three yellow wires at the P3 male side plug (see photo). I got nothing - although there was voltage at all 3 on the female side (I think it was pretty low, maybe 10VDC or less). In any case, voltage at the battery is not good - running it merely pulls from the battery, getting lower and lower the more I run it, like a total loss system.
2) Tried jumping from my car battery directly to the bike battery, to see if the extra voltage would get the dead two cylinders to fire, but no luck.
I have a new regulator that I can try - seems like a long shot, but no huge expense.
Again, I'm kind of inclined to ask (if anyone out there has experience with this): Am I dealing with two separate, unrelated symptoms here? i.e. could the lack of charging the battery have anything to do with it running on two cylinders? Or is it time to pull the carbs (looks like fun) and clean them?
1) Did a suggested test of the alternator output - checking for 24VDC (?), while running, from each of the three yellow wires at the P3 male side plug (see photo). I got nothing - although there was voltage at all 3 on the female side (I think it was pretty low, maybe 10VDC or less). In any case, voltage at the battery is not good - running it merely pulls from the battery, getting lower and lower the more I run it, like a total loss system.
2) Tried jumping from my car battery directly to the bike battery, to see if the extra voltage would get the dead two cylinders to fire, but no luck.
I have a new regulator that I can try - seems like a long shot, but no huge expense.
Again, I'm kind of inclined to ask (if anyone out there has experience with this): Am I dealing with two separate, unrelated symptoms here? i.e. could the lack of charging the battery have anything to do with it running on two cylinders? Or is it time to pull the carbs (looks like fun) and clean them?
ChriSTian_64
Site Supporter
@claytonia Clay, I'm so sorry you are still having hard time solving this.
Yeah, it's not easy sometime...
Man.... You need a bit of help from heaven now.
The problem have to be related to air, fuel or sparks, right ?
I'm just thinking out loud, here...
What could be an easy way to bypass the fuel pump, just to exclude it from possible cause of the problem ?
In the tool section of some online retailers, I've seen a kind of rubber pouch with a hose (same principle than a camping shower ) to act as a temporary gaz tank / fuel pump bypass.
Do you have a date code stamped on your fuel pump ?
My ST1100 is from 2000 and only had 20K miles when I got it two years ago.
Despite the low mileage, the gas pump had been replaced in 2014, before being sold to the 2nd owner, because the bike had been sitting for too long, probably with an empty tank.
Maybe you have some fuel, but the pressure is not right ?
Yeah, it's not easy sometime...
Man.... You need a bit of help from heaven now.
The problem have to be related to air, fuel or sparks, right ?
I'm just thinking out loud, here...
What could be an easy way to bypass the fuel pump, just to exclude it from possible cause of the problem ?
In the tool section of some online retailers, I've seen a kind of rubber pouch with a hose (same principle than a camping shower ) to act as a temporary gaz tank / fuel pump bypass.
Do you have a date code stamped on your fuel pump ?
My ST1100 is from 2000 and only had 20K miles when I got it two years ago.
Despite the low mileage, the gas pump had been replaced in 2014, before being sold to the 2nd owner, because the bike had been sitting for too long, probably with an empty tank.
Maybe you have some fuel, but the pressure is not right ?
Thanks Christian. I have a remote gas container like you describe already - I'll give it a try today. It sounds like a potential cause of this problem.
Smudgemo
Intermodal Man of Mystery
Any of the symptoms you're experiencing sound like carb problems related here? http://koczarski.com/mmartin/CarbDiaphragm.htm
Pulling the carbs really isn't difficult, so don't let that stop you if your troubleshooting leads you there. You'll want to replace all of the old rubber parts under the carbs including cooling lines if it's all original while it's exposed, though.
Pulling the carbs really isn't difficult, so don't let that stop you if your troubleshooting leads you there. You'll want to replace all of the old rubber parts under the carbs including cooling lines if it's all original while it's exposed, though.