Jetscrazy87 Posted October 17, 2015 Share Posted October 17, 2015 Hey everyone, I'm one of the new guys and I'm in need of some assistance...If you haven't seen my introduction thread please check it out! Now to the task at hand...i have a 1980 sr250 I picked up a couple months back for next to nothing...it was in decent condition and I thought it would make for a rather inexpensive and fun tracker project. Anyway, I've hit a brick wall with it this week, for some reason I can't get this thing to spark. I checked the resistance on the ignition coil primary and secondary, pick up coil, and the starting solenoid...everything checked out good, but this is where it gets weird. when the ignition switch is on and the stop/run switch in run, I get a constant 12v on the spark plug wire. If i switch to "stop" i lose the 12v...strange right? Why would i see a constant 12v on the plug wire? i've never seen anything like it. I know there isnt really a way to check out the CDI box and i don't want to go out and buy one until im sure thats the problem. Also, I am having some troubles with the neutral switch. with the ignition on and the bike switched to run i have continuity from the actual neutral switch to the harness at the headlight and thats good, theres 12v there as well, but i cant get the light on the speedometer to light, all other lights work so far. It could be just the bulb but I'm not to sure, but then i started thinking maybe its related to the no spark. Any help would be greatly appreciated.Thanks- Matt Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 17, 2015 Moderator Share Posted October 17, 2015 the neutral switch is needed to tell the TCI that you are in neurtal and its ok to fire up the bike.if you have a switch on the clutch, you could pull the clutch in as that over rides the neutral.if you don't, run an earth from the TCI to get spark but make sure your in neutral Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 17, 2015 Author Share Posted October 17, 2015 thank you for your response...the bike does have a clutch switch as well which i have to earth...but still no spark. My neutral light doesn't seem to work for some reason. How does the neutral switch work? is it constant 12v switched or switched ground? Anyway with the neutral switch bypassed (clutch switch to earth) i hear the safety relay click which makes me believe its working, but still no spark! this is getting very frustrating...im almost done with my build but these electrical issues are driving me nuts! anymore help or ideas are greatly appreciated! Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 18, 2015 Moderator Share Posted October 18, 2015 check all earths to frame connections. neutral is an earth switch, hence it earths the TCI. TCI's work by earthing to complete the current, coils should have 12v on ignition switch on just check all connections are clean too Link to comment Share on other sites More sharing options...
Tommy xs Posted October 18, 2015 Share Posted October 18, 2015 My guess would be to change the neutral switch and check out the clutch switch as they often fail, not got a clue as to why you would get the readings your getting thou, like Drew said try cleaning all connections Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 19, 2015 Author Share Posted October 19, 2015 I grounded out the neutral switch and still no spark. I double checked the ignition coil. The primary was 3ohms and the secondary was 19k ohms...I've looked up what the bike specs but ive gotten mixed results. Does anyone know off hand what the manual calls for? The secondary numbers i got were from 8-10k ohms, if thats right and im 7k over, is thats the problem ? Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 23, 2015 Author Share Posted October 23, 2015 Ok so just wanted to post a little update. I ordered a new ignition coil to see if that would fix the high resistance on the secondary side of the coil turns out that the wire to the plug from the coil is actually the cause of the high resistance. I reterminated the end of the plug wire and there was still 17.5 k ohms of resistance. I completely did away with the plug cap and had the proper 8.5 ohms of resistance. Tried the wire strait to the plug and grounded to the head and no spark. Only thing left is the cdi box. Oh and i still have a constant 12v on the plug wire all the time, that still makes no sense to me. Any help would be great. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 23, 2015 Moderator Share Posted October 23, 2015 you'll burn out the coil (and probably the TCI) if the ignition is on all the time without the engine running. must be the ignition switch. Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 23, 2015 Author Share Posted October 23, 2015 The ignition witch is brand new. The starter button doesnt work but thats just bad contacts. Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 25, 2015 Author Share Posted October 25, 2015 Update from this morning. I figured out why the starter switch wasn't worker, it wasn't bad contacts it was bad ground. After fixing that and cleaning the contacts on the harness to the tci box i finally saw a spark! Yea this is an exciting feet being ive been messing with this spark issue for a week now. But its not all good yet...when i press the start button i see a nice bright spark but as soon as i continue to hold the button down the spark disappears....if i hit the button intermittently i see a spark every time, if i hold the button down i lose it. Any ideas? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 25, 2015 Moderator Share Posted October 25, 2015 so you didn't check all earth connections and check connections like I said a week ago Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 26, 2015 Author Share Posted October 26, 2015 it's a little more complicated then that, the ground for the switch is actually a metal tab that bites the handle bar and creates the ground. That tab wasn't biting through the paint and I wasn't getting good ground, so i alligator clipped from the ground in my headlight bucket to the switch and that fixed that. Now i could actually use the start button to crank the engine instead of jumping the solenoid. But i still have a spark problem...when i press the start button i see a nice bright spark but as soon as i continue to hold the button down the spark disappears....if i hit the button intermittently i see a spark every time, if i hold the button down i lose it. Any ideas? Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 26, 2015 Moderator Share Posted October 26, 2015 battery needs charging, it may be supping all those spare amps for the starter motor Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 27, 2015 Author Share Posted October 27, 2015 The battery is brand new...i will charge it anyway but it has 12.8v...im really struggling here, ill put a charger on the batter...is there anything else you can think of? If this doesnt work i think i might start opening up the harness and looking for bad wires and shorts. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 27, 2015 Moderator Share Posted October 27, 2015 maybe try a push start to eliminate the starter using available amps. get a multimeter on the 12v feed to coil and see what happens on starting Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted October 27, 2015 Author Share Posted October 27, 2015 so i cranked the engine with a drill instead of using the ignition system and I got no spark what so ever. when cranking with the starter with my multimeter at the coil I drop into the lower 10v range. Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted November 3, 2015 Author Share Posted November 3, 2015 here's an update...i still have no spark, i actually cant even get the spark i was getting when just pushing the button...i installed a new coil. fully charged the battery, and even moved the ground from the frame to the engine. still i have nothing, at this point I am at a cross roads...i have put a lot of time into this bike, but I paid next to nothing for it, so do I keep wasting my time on something that i cant find the parts for(CDI box) or do i sell it for whatever i can get? I am trying to find someone who has the same bike, so i can test out my CDI(TDI)box but it seems they are hard to find and ebay has nothing as of now...any input or ideas would be great. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted November 3, 2015 Moderator Share Posted November 3, 2015 probably your best bet, google the number on the TCI and see what pops up Link to comment Share on other sites More sharing options...
blackhat250 Posted November 6, 2015 Share Posted November 6, 2015 Ok, try this, switch on ignition, then unplug the CDI, , Switch off iggy , then plug in CDI , , and try start it,, Link to comment Share on other sites More sharing options...
Jetscrazy87 Posted November 6, 2015 Author Share Posted November 6, 2015 Ok so i bought a NOS TCI and thats not the problem. Only other thing i can try to replace is pickup coil. Blackhat ill give that a try thanks for the suggestion. Link to comment Share on other sites More sharing options...
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