I have a 1977 Moto-Ski Spirit with a 250 single. I just purchased it and am currently putting it back together. I found the cam was not installed correctly and have corrected that problem. The timing and points have been adjusted to spec. I have no spark? Is there and easy way to test the Mag and condenser? I tried to put a volt meter on the mag wire to the coil (disconnected) - I only get a spike of 2 volts when I pull it over.


Thanks.....

Don't know how to test the magneto, but condensers are only about $3 each. So I'd replace the condenser for sure. Worse case scenario, you're out 3 bucks, and when you finally get the problem fixed, you know you're condenser should be good for another 10 years.

In addition to the condenser, I also change the points. At the very least, make sure they are clean.

To test the ignition coil... there is a primary and secondary coil. They are not connected, so with a multi-meter you should not see any continuity between them. In other words you should not see a connection between the spark plug lead and wire that feeds the coil. If a connection is present, the coil should be replaced.

Basic theory of operation, power is normally fed to primary coil. When the points open, the magnetic field in the primary collapses, creating a brief electrical current in the second coil, causing your spark.

A word of advice based on experience, only replace the points and condensor with Bosch OEM parts. You will not be sorry. Aftermarket are no where near as good or reliable. They are more expensive but well worth it.
Although the timing is effected by the point gap, you can't assume that the timing will be correct because the point gap apperas to be right. You will not likely see much aof a spike on a volt meter from the primary coil.
What you need to do, is hook everything up the way it is supposed to be and get a continuity light, with a 1 1/2 volt battery in it and connect it between gorund and the high side of the input to the coil. you should show a light on no matter where the flywheel is. When you rotate the flywheel, the light intensity will change when the points open and close. To time it, you need to hold the spark advance finger all the way advanced and align the mark n the flywheel up with the cntre mark on the housing. That is nominal. You move the timing by adjusting the point gap. The stator plate can be moved as well but 99% of the time, the stator has never been moved since the factory and just adjusting the point gap works fine.
This method works well and I have used it many times.

Thanks for the advice, I have put in new points and condenser. checked all the wires and I got one spark then only a very faint spark. I will check the timing with a continuity light. It seems like there is not enough voltage going to the coil? If I put a volt meter on the wire to the head light and pulled with no plug I only get 2 volts?

Should I have 12 volts going into the coil?

The voltage coming from the coil will be very hard to measure with a meter unless you have a very fast reacting meter. It is also a form of AC and not DC. Not sure what range you used to measure it with.
Try another secondary coil if you can. Thye are usually the culprit and not the primary.

The ignition coil tested ok at 3.4 ohms. Installed a new external coil and it started first pull....

thanks for the help

Glad you got it working so now you can start to enjoy the sled!!