What did your gremlin do to you today?

Ok, I'm ripping off the What did you do to your Yamaha today thread.. But I think this will be just as popular since these little buggers are everywhere!

-------

Well I rode into work today, bike started up no problem, same as always. I finish my shift at 10pm and go out to go home, and all she does is crank. No fire. It will give a little hit as I let off the starter button, but absolutely nothing after. I know all about the 'over efficiency' of the starters in these bikes, so thinking my battery is just weak. I try to pop start it. Accomplished nothing but winding myself. I smelled the exhaust while it was cranking and it was most certainly getting gas. I pulled a plug and grounded it. No spark while cranking, but it gives one weak hit as the start button is released. Of course I left my multimeter on my desk inside, (and by this time everyones gone so I cant even get back in the building), so I can't test anything, all I can do is listen for relays to click, scrape off connectors, wiggle things around, check fuses, etc. Nothing helps. (And at this point, I have the tank, panels, and headlight off). It's 1:30am, and I had to give up because the parking lot lights turned off. I put the bike back together, locked it up, and walked 13 miles home. I am so disgusted. Now I have to go back in the morning and try and figure out WTF is going on.

Now you...

 

Check your starter brushes. Sounds like its pulling all your power away from your ignition system. When you let off the starter switch, it sends power back to your ignition for a sec too late. Oh gremlins keep losening up my tach. cable on the engine.

 

From the automotive side, if a customer described the symptoms you described (spark only when ignition returned to run position), I'd recommend a new ignition switch. In our case, the ignition circuit should be "hot" whenever the ignition switch is in the on position. I suspect, from what you described, that you're not getting all the juice to the ignition circuit you should, i.e. when you crank the bike, the starter is causing such a voltage drop that the ignitor unit/coils are not firing. I'd look for dirty connections/bad or broken wires going to the ignitor and coils. You may be able to test for voltage drop at the ignitor during and after cranking the starter. If it's more than a volt or two, I'd really be concerned.

Seeing as how we're getting on into late September, I'd suspect corrosion on terminals and connections. Just in the last week I've seen a marked increase at the store of electrical related problems. Heck, the last customer of the day, yesterday, asked if I could test his alternator because his Subaru wouldn't start that morning due to a dead battery. I grabbed my tester and walked out with him to his car. He popped the hood and guess what I saw? ...a positive terminal that was about twice the size it should be for all the corrosion built up on it. I went ahead and tested his charging system, but told him his problem was with the corroded terminal. It was surely interfering with the alternator's ability to recharge the battery.

You may be able to bypass the ignition circuit by running a jumper wire straight from the battery to the red/white wire of the ignitor. If it starts right up, then you definitely know you've got a bad connection somewhere. Anyway, that's my 2¢ worth. Hope it's useful and happy gremlin hunting.

 

After another afternoon and late night before and after work messing with the bike in the parking lot (this time at least I had my meter and Haynes manual with me so I wasn't just blindly fiddling with things), I have finally found the problem. I have a bad pickup coil. Partially my fault for only checking the outer cylinders for spark (I forgot thecoils were outer/inner instead of left/right), I discovered that the inner cylinders had perfect spark, but the outers only have a single pop when the starter button is released. I swapped the coil primary leads and the problem shifted to the other coil. Then I tested the pickup resistance...... 649 ohms and OPEN. HELLO!!! Hoping it was a broken wire somewhere between the pickup and TCI box, I poked the meter probes through the insulation right at the pickup coil, but no joy.

Here's where things get weird..

Admitting defeat, I put the bike back together and was ready to go catch a bus to get me somewhat closer to home, and I gave it one last disgusted kick and try before I left... But this time the engine caught and started stumbling and backfiring. I gave it gas, and it revved! It ran like sh*t but it ran. There is one big climb uphill then a very long coastable downhill, and then within a few hundred feet of the bottom is my Yammie dealer. So I figured if it got me up the hill before it died, I could coast it all the way to the dealer and leave it in the parking lot and walk from there if need be. But by some stroke of sheer luck or a guardian angel or something, I made it all the way home. I turned it off in my driveway, then tried to start it again, and guess what? NADA.

I don't know what it was, but I'll take it. Now... I found a pickup on fleabay, (just FYI, the pickup assembly is $280 special order from the dealer 8O 8O 8O ) and he is going to try and express mail it to me from MN so I have it by sat, but I can't bank on it. Is there a coil that I can salvage from a junkyard car or something that provided it has the right size/resistance will get me trhough the weekend if needed?

 

Looking at a picture in the manual, I've not seen one that looks similar in all my years of selling parts for cars. In other words, don't hold your breath. You can, however, rewind the coil if you're feeling ambitious. You'd have to strip the pick-up of its wire, counting the number of turns that come off it and the wire gage size. Then, go the radio shack and by some magnet wire and rewind it. It's actually pretty simple to do; just extremely time consuming. I'll look through the picture guide for a pick-up when I get to work (for automobiles and small engines). If I find one that looks similar, I'll post again with a part number/application.

 

Once I broke off the epoxy shell, the coil looked very straightforward.. however, it looks to be several hundred feet of 30 or 32ga wire, which rules out sourcing at rat shack They only sell magnet wire in 100ft spools. Ugh. I dug through a couple old boxes and fouond a new pickup coil from one of my old trucks. It was about the right size once I punched the core out, but the resistance was only 300Ω. I was going to give it a try, but in the process of trying to enlarge the hole to make it fit over the yamaha core/mounting plate, I managed to wreck it. If I were to go get another of those (since parts for old american engines are real cheap ), anyone think it would work? 300Ω is out of spec for the yamaha coil, but not by much..

 

I'd look a bit more at the original. Seems to me there is a better than decent chance there is a break inside one of the leads going into it.

If the winding is really bad you might look for people that service electric motors. Perhaps one of them has the wire and equipment to re-wind it.

 

Are these guys near you? It appears they have the right size and quantity of wire.

 

Nah, not close enough to justify going down there. Like I said, Im just trying to come up with a quick and cheap fix that'll get me through the weekend if the replacement doesn't get here tomorrow..

Carl its definitely the coil itself.. I cut the leads right at the coil and it still tests open. I was hoping it was wiring because wiring i can do now Again, its not worth it for me to have a coil made, i'm just trying to get teh bike to run for 2 days tops till the new coils get here so I can stop begging for rides :lol: