gdarrell Posted October 2, 2008 Author Share Posted October 2, 2008 if you have a smooth alloy points cover with plugs instaed of screw heads, you have TCI ignition. Ribbed with screws visible - points. check you are getting 12v to the suspect coil! its the smooth cover - so its TCI. At the risk of sounding ignorant (not hard for me), how do I check for the 12V at the coil? I checked the resistance on both coils and the output of the pickup (from the smooth box) and all the values were spot on with the book values (3 ohms for primary, 8.5Kohms for secondary, etc). So, that would suggest coils are good, but doesn't tell me if they are getting juice which is a really good question. I hooked up the DVM to the coil lead wires (not plug wire) and only get a few hundred mV. I rotated the engine slowly through the timing points but did not see a change. Obviously, I don't know what I am doing Link to comment Share on other sites More sharing options...
gdarrell Posted October 2, 2008 Author Share Posted October 2, 2008 Did you swap the plugs? Those things do go bad and that can be a failure point. Yes if you hook the timing light to the wire and get strobing then you have spark, but it could be not getting to the plug tip. Thats certainly worth trying as well as swapping plug wires. will try that tonight. Link to comment Share on other sites More sharing options...
gdarrell Posted October 5, 2008 Author Share Posted October 5, 2008 Ok, here's an update. Changed plugs, rechecked wire connections, fuses, etc. Still no luck.... I have convinced myself that if the TCI were shot, I wouldn't get any fire at all (can anyone confirm that? will it fire on only one side or fail altogether?) At any rate, tired of kicking with no luck and finally decided to tear the carbs down again Turns out my "good cleaning" wasn't as good as I thought it was. As soon as I opened them up, they were still really sticky on the inside with more traces of varnish. One of the floats was stuck (left side - coincidence??) So, today I took them completely apart and gave them a really good chemical soak. This time, they almost sparkle - sort of... Mostly back together, still need to set the floats. Stay tuned, if it doesn't start tomorrow, then I am out of ideas Link to comment Share on other sites More sharing options...
Mister B Posted April 1, 2009 Share Posted April 1, 2009 Hey Gdarrel, I am having THE EXACT same problem with my 82' SECA, went through the same diagnostic paces as you and finally found that the left plug is getting an extremely weak spark. It fires once if at all at random when cranking the engine while the right will fire multiple times in the same time frame. Did you ever solve the problem with your bike? Link to comment Share on other sites More sharing options...
KingKennyWannabee Posted April 2, 2009 Share Posted April 2, 2009 I am going through this post because my bike has to be kick-started because the starter doesn;t work. Thanks for the ideas. As soon as it warms up a bit, I'll be working on it and keep my results posted. :-) Link to comment Share on other sites More sharing options...
gdarrell Posted April 3, 2009 Author Share Posted April 3, 2009 Hey Gdarrel, I am having THE EXACT same problem with my 82' SECA, went through the same diagnostic paces as you and finally found that the left plug is getting an extremely weak spark. It fires once if at all at random when cranking the engine while the right will fire multiple times in the same time frame. Did you ever solve the problem with your bike? I did finally get the old girl running. I was able to check for a spark by hooking up my timing light, turning on the ignition, kill switch set to "run", and giving it a kick. The light would strobe well on one side but not at all on the other. That convince me that I wasn't getting fire on one side. Swapped coils from one side to the other with no effect which told me my coils weren't the issue (shame I had already bought an extra set off ebay!). Did a little research and got lucky with a random hit on a google search that led me to believe the TCI box was bad. Apparently, there is a failure mode where one of the wires inside the box comes loose from vibration (and old age) and while the box is "good", its only sending out a signal on one side (spark on one side). The website talked about opening up the box and finding this connection and resoldering. Easy fix and there was also a link to a guy that could rebuild them. this was for some XS 600s I think and that was all he worked on. Apparently there is no test for the box - you can replace with a known good one, but who has those laying around? Anyway, I ended up and got lucky and found a box for less that $30 bucks, so I bought it. Plugged it in and bike was now getting fire on both sides - success!! Well, not so quick. I was finally able to get it fired up after a little shot of starting fluid (ether). Its running good, still needs carb synch, but I have put a few miles on it (maybe 100 or so) in the last month. I didn't open up my old box yet to check for the loose wires, but its on my list of things to do to check the solder connections. If you have checked coil resistance, plugs, and plug wires, then you might consider opening up the box to look for a loose solder joint. I will also say that when every one on the forum talks about voltage, they are correct. It just won't work without about 11 volts min to the ignition circuit, so you should check that as well. Good Luck and let me know how it comes out!! Painted the bike this week and will post some pics soon. Big change since she was under the apple tree Link to comment Share on other sites More sharing options...
gdarrell Posted April 3, 2009 Author Share Posted April 3, 2009 I am going through this post because my bike has to be kick-started because the starter doesn;t work. Thanks for the ideas. As soon as it warms up a bit, I'll be working on it and keep my results posted. :-) I am convinced that my problem is the "starter clutch." I am now able to get it kicked and running pretty much on first or second kick now. After I finally got the carbs really really clean and solved the TCI ignition problem, she started firing. for the first several times, it took starting fluid, but it seems to be happy now and starts easily on middle choke position and good strong kick. Let me know how that job goes. I have been reluctant to tear into it because I wanted to get it running and make sure it was otherwise mechanically sound. I have put on a 100 miles, so I think it is.... But, I don't really know what is involved with the starter clutch replacement. If anyone does or has done it, a post on that would be great!! Link to comment Share on other sites More sharing options...
bowser09 Posted May 13, 2009 Share Posted May 13, 2009 I am convinced that my problem is the "starter clutch." I am now able to get it kicked and running pretty much on first or second kick now. After I finally got the carbs really really clean and solved the TCI ignition problem, she started firing. for the first several times, it took starting fluid, but it seems to be happy now and starts easily on middle choke position and good strong kick. Let me know how that job goes. I have been reluctant to tear into it because I wanted to get it running and make sure it was otherwise mechanically sound. I have put on a 100 miles, so I think it is.... But, I don't really know what is involved with the starter clutch replacement. If anyone does or has done it, a post on that would be great!! hello, i have been reading this forum and it gave me alot of info on my problem with my 79 xs400. havnt cleaned the carbs yet, but my starter works, im not getting fire on either side spark plug wires, is there a way i could just replace the wires cause i think my coils are in good shape, put the test light to it and they are doing what they are suppost to do just nothing to the wires, there was a one time when my dad had a test light to it and i was holding the end of the wire with the sparkplug on the end and it shocked the hell out me, but after that it didnt fire again, the reason im asking about the wires cause they look like they are apoxeed or somethin inside the coil, also, the gas tank, it is rusted inside, is there a way i could get that cleaned, Link to comment Share on other sites More sharing options...
gdarrell Posted May 15, 2009 Author Share Posted May 15, 2009 I did finally get the old girl running. ...... Painted the bike this week and will post some pics soon. Big change since she was under the apple tree what do you guys think? Link to comment Share on other sites More sharing options...
gdarrell Posted May 15, 2009 Author Share Posted May 15, 2009 hello, i have been reading this forum and it gave me alot of info on my problem with my 79 xs400. havnt cleaned the carbs yet, but my starter works, im not getting fire on either side spark plug wires, is there a way i could just replace the wires cause i think my coils are in good shape, put the test light to it and they are doing what they are suppost to do just nothing to the wires, there was a one time when my dad had a test light to it and i was holding the end of the wire with the sparkplug on the end and it shocked the hell out me, but after that it didnt fire again, the reason im asking about the wires cause they look like they are apoxeed or somethin inside the coil, also, the gas tank, it is rusted inside, is there a way i could get that cleaned, I replaced my wires with wires from AutoZone (got them cheaper) and reused the caps. This may not be advisable, so I would let some of the other guys here weigh in on that. It worked for me, but the wire size is one smaller than the original.... Check the wires with a timing light to see that you are still getting spark to the plugs. If tank is really bad, might consider getting one that is in better shape off ebay. Mine was not bad. I have seen some tanks with the internal coating applied, but the ones I have seen are peeling on the inside. Doesn't give me a lot of confidence. could have been a bad application, though, or maybe just age. If you haven't cleaned the carbs, then I would disconnect the fuel line until you do. No point in putting more junk in there or through the cylinder heads. Link to comment Share on other sites More sharing options...
cafebrad Posted May 18, 2009 Share Posted May 18, 2009 hey i'm pretty new her too, but im having almost the exact same issue. bike was running fine , if a bit lean -high idle. now the right cylinder only fires. if i remember correctly the left side cut out off and on a few months ago. anyways now its right side only and i have switched the plugs, switched the coils and put in new points and its running the same. i pulled and cleaned the left carb but it was already surprisingly good for sitting quite awhile. any new ideas? Link to comment Share on other sites More sharing options...
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