XT 125 with no spark

Hey guys,
I have a XT125 that I have some attachment to and would rather not ditch. I know it's an 80s no power small bore nothing bike but I am not ready to give up on it yet!

Long story short, typical story, ran well. Sat for a couple of years now she no go. It had spark when I started messing with it a couple of nights ago, now there is zero spark. I believe that the coil, wire and plug are good. I am leaning towards the CDI. A new CDI for it isn't cheap so I don't really want to jump into one right away.

So, does anyone have a XT that we could try my CDI on? Does anyone smarter than I have any bright ideas? It shouldn't be the battery since these bikes will run without one.

Thanks in advance
John

As I lay in bed last night I realized I haven't checked the kickstand switch... Possibly?

The spark is gone? Try an evening by the fire with a nice bottle of wine, chocolate dipped strawberries & some Barry White tunes...

Failing that other than the side stand switch, does the XT have a clutch switch? My KLR had ignition issues related to that some years ago.

Hmm that's a good point I didn't try to sweet talk her and give her any romance. I will spread rose pedals around the shop floor next time I am out there!

I don't think that it has a clutch switch or neutral but I will check that out too.

A clutch switch would only disable the electric starter, which I dont think you have anyways.

Try a new spark plug. Sometimes they look fine, but they are not.

Take apart all the electical connections and make sure they are clean and make sure the kill and key switches are working properly. Make sure all of the grounds have good connections.

If that doesnt work, then start checking the stator, coil and CDI.

Spark plug was the first thing I tried. I switched out a couple of new ones. Cleaning the key switches is a good call too. I will check that out .

Did you try the kickstand switch?

I once got a 1 year old XT250 for only $300 (back in 1984). It suffered from an irritating problem where it would randomly suffer from misfiring and occasionally cutting right out. The dealer could not find anything wrong, and neither could Yamaha as they could never reproduce the problem. The guy was so pissed he offered me the bike for $300. Of course I could not pass it up. Quite accidentally I discovered it was the kickstand switch. I wanted to run it on the stand to see if I could detect anything, so I bypassed the switch. Of course I found nothing wrong, so I just started riding it. For 3 weeks I never had a problem with it - until, for some unknown reason, I re-connected that damn switch. Within 30 minutes of riding, the bike started to misfire.

Just pull that switch off, throw it away and bypass the connection. Even if that is not the problem you have now, it likely will be someday.

I haven't checked the kickstand switch yet. But I thought of that very shortly after I posted.

I removed the kickstand switch and wired it back to itself. No luck. Ignition switch looked good and clean but cleaned it up since I was there anyways. Going through all the grounds and connections now but I am having no luck yet. Life would be so much easier if I had two bikes to swap parts for testing.....

Has anyone ever baked a CDI? In searching for a new CDI I stumbled across a video of a guy who claims that baking a CDI sometimes makes them work again by drying them out. Anyone try it? Advice?

Hot damn it worked! Decided to buy a used toaster oven to give it a shot. I baked the CDI at 200f for about 2hrs +-. When I pulled it out I had melted one of the connectors pretty barely so I had to cut it away to hook it back up. Plugged it back in and sure enough there was spark! So this means one of two things I think. Either there was moisture inside from a bad seal at the back where the epoxy is or there is bad connection inside and the heat allowed it to make a rough connection . I am hopeful that it was moisture inside because it looked like the back was seperating. I will let it cool off and try it again tomorrow hopefully . I will also caulk around the back to try and seal it up as best as possible . Fingers crossed!

Moisture. The plastic would never have survived the temperatures required to melt solder.

Congratulations, both on your success and on your tenacity.

Thanks! I am also siding on moisture but have read at least one case where the heat has allowed enough movement that it temporarily closed the break. Once it cools it allows it to open back up. I know it wouldn't have melted the solder.

At the very least you now know where the problem is ,you wont be wasting money on a guess .

Well after multiple long slow bakes I gave up on the CDI. Definitely the problem, but not solving itself so easily. Basically bake it and it works. Go back a couple of days later dead.

Posted on Kijiji in search of one and ended up having a guy contact me from Smith falls saying he had a basket case of an XT. I happened to be heading to Ottawa for a trade show so I grabbed it on the way up. Nice thing about a basket case is that you can lay them down under the toneau cover when the trailer is full! I was able to get most of a bike for a good price CDI was good, muffler was better than mine and a couple of other small pieces. Bike is up and running and ready to chase my daughter around the field/bush while she learns to ride!

Best part is I got to buy it from inside of this trailer!!! Plus a obligatory family photo of all the running ponies

I have an XR 100 for my daughter that I couldn't figure out a carb problem. Had someone tune the bike and clean carb and still needed choke to run, beech to start etc.. Bought an new Ebay carb in frustration for $25. Took the tank off to switch it and realized there was crap in the fuel ( sat for a few years to boot). Turns out the petcock valve was full of sludge and the brass feeder tube corroded. New one installed, starts right away and runs like a charm!

Ok I know I should just let a dead horse die but...

I've got spark but it's intermittent. Sparks well for a few kicks, then slowly gets worse until there is now spark.

New plug, changed the CDI already, new plug boot...

Coil? Still CDI?

Thoughts

Cheers
John

I usually start with the easy (cheap) stuff. Plug, plug wire, coil.
Once had a 1942 Harley 45 c.i. WLC that I rebuilt... new plug but no spark. I went through everything and then found my new plug was bad.

Aaaaaand CDI! Coil swap, plug swap ,wire and cap.....

With nothing but time busted out the toaster oven again, long slow bake and we have a winner! She's a one kick wonder now. Much to my neighbors dismay I have had my daughter's out doing laps around my yard. With any luck I will be chasing my oldest around on her xr by summer!

Show us the time-lapse video now.

B