Help - 1974 WR 250 Starts easy, runs fine, and quits

I posted earlier about this. My new to me 250 WR has a Bing and starts on the third kick or so. Hit the tickler until gas comes out the carb vent, kick, and she starts. She runs great for 10 or 15 minutes or so, and then she'll start breaking up and then die. I can restart her in a few minutes.

I took the Bing apart today and cleaned everything. Nothing dramatic. The carb actually seemed pretty clean. Floats were good, no leaks, needle looked good, all the passages were clear, etc. I also checked fuel flow from the tank and switched gas caps with my 360 that runs fine.

She quit again after 15 minutes or so. She had fuel to the carb. It wasn't the gas cap. This one is fine and I took it off just to be sure. Last time this happened, I pulled the (hot) plug and had spark. So, I figured it was fuel. Maybe it wasn't.

The bike has a Baja Designs headlight and taillight/brake light. Could it be something with the ignition? Something getting heated up? Help. I'm at a loss. Bike has done this since I got it. I really like, and want to get it sorted out.

What ignition system is on the bike?
Femsa flywheel magneto?

I'd place my bets on ignition too.

Now, that might change if you were to describe what you mean by "breaking up" before it dies. But if you mean run strong - miss - run strong - miss longer - run strong - dies, that's probably ignition.

On the other hand, if "Breaking Up" means something like the bike doesn't run in a matter consistent with your throttle position, then maybe fuel.

You might try carrying a spare plug with you so you can just pop the cap, place it on the cold plug, and get to kicking (less time for things to cool down compared to pulling the plug), or maybe someone has some specs for your electronics you can measure.

Classic symptoms of ignition breaking down, if your bike has points replace the condenser, replace points if burnt and pitted, if you have Motosplatt send it to someone who knows how to repair it.

shouldn't be the kill switch but check it isn't rubbing anywhere... a mate bought a 98 250 for nix years ago as the po had just replaced the top end but the bike started breaking down real bad and he was ovr it...turned out the ign wires were rubbing on the flywheel and as it warmed up it shorted more and more... ol mate spotted the wear mark on the wires and took a punt and offered him 500 bucks...bit of tape and she was a real goer! you need to go thru the power system start to finish as suggested above...my money is on the condenser...ornery little c*ksuckers they can be...ive resolved (many years ago) that if it has points I wont buy it...

but to people of a certain age much easier to understand and repair!!

yep, just that bit older than me. im dyslexic and fumble fingered at the best of times...setting points is a mission I just hate...even in a car! points in a small flywheel??/ yeeesh!

ive owned 1 new SEM ..no probs...1 very old SEM no problems, 1 very old motosplat..no probs...no doubt my run of very good luck will come to a sparkless stop sooner or later

Thanks for all the replies. I got a few minutes and checked the bike--its a FEMSA points/condenser ignition. I called Husky John--he's been incredibly helpful when I call him--and he agreed with all of you. It's an ignition problem. I'm going to try a coil first (easiest), then points/condenser. Husky John doesn't sell FEMSA stuff. I'm going to start my search, but just curious if anybody had a good source. I'll also need a flywheel puller. Or, I can buy a Power Dynamo ignition and be done.

I have a femsa on my 73 360. I don't ride it much but it works fine. I'm sure there are some parts somewhere. You can try Stahls husqvarna. They had parts for mine. If you plan on using the bike then it would be worth getting a new ignition.

Any condensor will do the job, just get one for an older car no need to pull the flywheel mount it up by the coil and connect to the low tension lead there, then you can reach through the flywheel inspection hole and snip the lead to the old one. clean and gap the points and I would be very surprised if she doesn't run sweet as a nut.

As for the coil...forget a used Femsa.
The Emgo orange "magic" coil works just fine with the Femsa points system.
< $20 from many vendors including Matt at Speed and Sport.
http://www.speedandsport.com/parts/ignition-lighting/

Heres a primary coil with lighting coil for your bike
http://www.ebay.com/itm/1972-HUSQVA...73066bb&pid=100005&rk=4&rkt=6&sd=232348140787

Heres a secondary coil
http://www.speedandsport.com/index.php/parts/ignition-lighting/ignition-coil/

Heres a puller, its the 33mm x 1.5mm pitch

The Femsa ignition from the 70's proved to dependable. I raced several Huskys during the 70's and they all had a Femsa, they never let me down. Now if setting points is your idea of a nightmare, and for some it can be, then maybe an electronic ignition is for you. Personally I would spend the few bucks to fix the Femsa and the 100's of dollars saved by not buying an electronic I would use to get something else for the bike. I've always felt that Husky included the Femsa ignition on the 75 360GP due to its dependability but I could be mistaken. Another thing, if more headlight wattage is important to you then maybe a new electronic ignition is the way to go.

Thanks again for the great replies, and the Speed and Sport site. I hadn't found that one. So, if I got this right, I can either get points, condenser and coil from Speed and Sport for under $50 total and try that, or go with the Power Dynamo for $510 and try that.

I don't care about the headlight, except that it has to work. Both my Huskys are tagged and plated. I virtually never ride them on the street (the 250 not at all because it dies after 15 minutes), but its been fun on a Sunday to hop on the 360 (if it mercifully starts easily) and ride over to a friend's and ride around his field. I like the 250 because its so much easier to start. I really want to get it sorted. Here's the 250 (everybody likes pictures, right?) Hereout.

Nice looking bike. Looking at Swedish vintage iron never gets old.

I would go with the stock system. get all new stuff and the puller, pull it apart, fit it up with new stuff , reassemble and set the points and you should be good to go for another 10 years.

funny as riding yesterday my 400 started dying at low revs, just an intermittent cut out that occ stalled the bike ...this post is catching ....im hoping its the kill switch which was damaged in a fall off the stand.. or a loose wire connector...hmmm

This post is catchy? Oh no a Swedish husky virus? I hope it stays with the bikes that have points.

Did you check the fuel cap will actually vent air in like it should

I used the cap off my 360 which runs great. And, I checked fuel flow to the carb as soon as it started breaking up and it looked fine, and I took the cap off at that point it didn't make any difference. I just ordered points, condenser, coil, and puller from Speed and Sport. Thanks for that. I didn't know about them. Nice guy took my order. I'll post up and let you know if this takes care of it. And I really hope its not some sort of virus that's catching.

It's a open or break in the coil windings as it heats up when the spark jumps across the opening between the coils it grows larger and stalls out.

So it's just the coil? I'm doing that first and trying that. I'll pull the flywheel and do the other stuff if the coil doesn't work