KFunk Posted June 6, 2009 Share Posted June 6, 2009 Yeah.. so I can go for like 10 minutes or more of good riding, then it can't idle and stumbles and dies. It'll start back up and go for a short time. The longer you wait for it to cool, the more time you can get riding again. But not for long... I previously thought it was a fuel level problem, as the right carb had a way high fuel level for some odd reason and that plug looked black/wet when it wouldn't keep running. I thought it might be flooding it once it got warmed up. So, I fixed that... and got riding just long enough to get far enough away to have a long walk/push home. I checked the spark plugs, and both look brown and OK. The fuel levels look OK in both carbs. Where do I look next? Something electrical getting hot? The battery has had some issues holding a charge. But if that were just running dead while riding, I'd think it wouldn't be able to restart at all. By the way, I'm only using the kick start, since my electric starter is dead and I don't wanna fix it yet. My headlight is also strangely not working, and I haven't found the source of that issue yet. Perhaps the relay, but I haven't gotten any help in my other thread on that subject yet. Link to comment Share on other sites More sharing options...
xmastree Posted June 6, 2009 Share Posted June 6, 2009 Stumbling and dying sounds more like fuel than electrics. Doing it when hot suggests running too rich, but I think you know that. Is the choke sticking on? How easily does it start from cold? Choke required? And finally, how's the fuel tank vent? If that's blocked it will die after a short while. Next time it dies, open the tank and listen for the inrush of air. Link to comment Share on other sites More sharing options...
KFunk Posted June 6, 2009 Author Share Posted June 6, 2009 Stumbling and dying sounds more like fuel than electrics. Doing it when hot suggests running too rich, but I think you know that. Is the choke sticking on? How easily does it start from cold? Choke required? And finally, how's the fuel tank vent? If that's blocked it will die after a short while. Next time it dies, open the tank and listen for the inrush of air. ... I think I might've fixed it. First I got it warmed up to the point it wouldn't really keep running at all, and verified the fuel level was OK via the hose out the bottom method on both carbs. It wasn't sucking dry or overflowing. It always favors the right cylinder only when idling/cold, and so I swapped the coils. I cleaned the connections with contact cleaner in the process. Put it back together, and it started running again, and sat idling for 5 minutes or more. I took it for a ride.. round and round the block over and over again... till the neighbors thought I was a weirdo, but they should know that already. Seems to run OK and pull strong for now, and starts back up OK. So yeah.. wonder if that one coil is just getting hot and quitting on me... or maybe the connection was weak. Link to comment Share on other sites More sharing options...
Cy Welch Posted June 10, 2009 Share Posted June 10, 2009 ... I think I might've fixed it. First I got it warmed up to the point it wouldn't really keep running at all, and verified the fuel level was OK via the hose out the bottom method on both carbs. It wasn't sucking dry or overflowing. It always favors the right cylinder only when idling/cold, and so I swapped the coils. I cleaned the connections with contact cleaner in the process. Put it back together, and it started running again, and sat idling for 5 minutes or more. I took it for a ride.. round and round the block over and over again... till the neighbors thought I was a weirdo, but they should know that already. Seems to run OK and pull strong for now, and starts back up OK. So yeah.. wonder if that one coil is just getting hot and quitting on me... or maybe the connection was weak. I know one of the things that I believe had the largest effect on my 400 after getting the carbs right was going through and cleaning ALL the connections. You would not believe how much corrosion can build up in almost 30 years. Link to comment Share on other sites More sharing options...
KFunk Posted June 10, 2009 Author Share Posted June 10, 2009 I know one of the things that I believe had the largest effect on my 400 after getting the carbs right was going through and cleaning ALL the connections. You would not believe how much corrosion can build up in almost 30 years. I'd already done most of them once or twice (including the connectors for the coils), and replaced the fuse box with some weather-proof in-line blade style fuse holders... since cleaning the coil connections was nothing new, I still think it was a coil itself causing the problem... still seems weird to me, though, and not sure if I trust it yet. I took it for a long drive out a country road the other day, and she still seems OK. I finally figured out the headlight problem as well. It was a metal relay under the battery area. I swapped it with the other one thats apparently a starter cut-out relay, and now the headlight works. I'm not using the starter anyways since its shot, so figure it doesn't need a good relay... Link to comment Share on other sites More sharing options...
KFunk Posted June 12, 2009 Author Share Posted June 12, 2009 well poop... back to dying again. I ran it all day yesterday, all around backroads, and about town. Then as I parked it at a restaurant, she sputtered and died. After like 40 minutes, I went out and started it, and it got me home, but acted funny. I got it out today, and only after running it a couple blocks, it died again... and now can't stay running.. Well any ideas? Link to comment Share on other sites More sharing options...
KFunk Posted June 12, 2009 Author Share Posted June 12, 2009 Oooooh, another idea. I think it's just running the battery dead and not recharging it. Any ideas if it sounds like that'd explain the symptoms? I just hooked it up to my trickle charger, and it shows the battery as being pretty damn dead. I tend to hook my bikes up to it at home when I'm diagnosing things or bored, just so I'm sure the lack of battery power isn't holding me back. But I haven't done that in a few days.... I guess I've tended to disregard the role of the battery in this bike, since I'm used to my other vehicles barely needing batteries at all. If it runs great after it gets charged up, I'd say that must be the problem. Now I guess its time to figure out why it isn't recharging.... Link to comment Share on other sites More sharing options...
Cy Welch Posted June 13, 2009 Share Posted June 13, 2009 Oooooh, another idea. I think it's just running the battery dead and not recharging it. Any ideas if it sounds like that'd explain the symptoms? I just hooked it up to my trickle charger, and it shows the battery as being pretty damn dead. I tend to hook my bikes up to it at home when I'm diagnosing things or bored, just so I'm sure the lack of battery power isn't holding me back. But I haven't done that in a few days.... I guess I've tended to disregard the role of the battery in this bike, since I'm used to my other vehicles barely needing batteries at all. If it runs great after it gets charged up, I'd say that must be the problem. Now I guess its time to figure out why it isn't recharging.... Check the charging voltage, at 2500 RPM is should be around 14.5 volts, if it's less than that it's not charging. Likely culprit would be the regulator, but there are a series of checks to be sure. Link to comment Share on other sites More sharing options...
KFunk Posted June 15, 2009 Author Share Posted June 15, 2009 Check the charging voltage, at 2500 RPM is should be around 14.5 volts, if it's less than that it's not charging. Likely culprit would be the regulator, but there are a series of checks to be sure. OK, I've got nowhere near that. It's 12.00 to 12.09V no matter how I rev it. I'm trying to do the checks in the PDF manual, but i can't find the wires they describe to check for resistances... they say to look for three white wires on one connector, and 2 green wires, orange, and gray wire on another connector, but I can't find those.... Link to comment Share on other sites More sharing options...
Cy Welch Posted June 16, 2009 Share Posted June 16, 2009 OK, I've got nowhere near that. It's 12.00 to 12.09V no matter how I rev it. I'm trying to do the checks in the PDF manual, but i can't find the wires they describe to check for resistances... they say to look for three white wires on one connector, and 2 green wires, orange, and gray wire on another connector, but I can't find those.... Yep, not charging, it's unlikely to be the stator, but if you follow the wires up from the stator towards the top of the bike you will find the connector with the white wires, the other connecter IIRC will be pretty close to there. However, my money would be on the regulator being bad. It's very seldom that one of the other components fails, as it seems to be the weak point in the system. Link to comment Share on other sites More sharing options...
KFunk Posted June 18, 2009 Author Share Posted June 18, 2009 Hooray! I have charging voltage! I found a couple pinched/broken wires under the front sprocket cover and patched them up. Seems to run fine now and gets like 14.8V easy. Link to comment Share on other sites More sharing options...
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