Vintage Dirt Bike Q & A

Can someone please direct me in the right direction? I have a 1976 MR175 that has no spark. Actually , it has spark if I hold the coil wire and turn it over by hand, I get a heck of a poke(Im assuming this is because Im grounding myself out)but no spark if hook the spark plug up to the coil wire. Is this a bad condenser on the coil? Any help would be greatly appreciated. Thanks

Assuming you are grounding the sparkplug to the cylinder and still have no spark, it sounds like you may have a bad cap connector on the end of the coil wire. They are about $5 and you unscrew the old one off the end of the wire and screw the new one on.

Unfortunately, I did try this hoping that would fix it, but no success. Thanks

check you ground. when you hold the wire your supplying a ground curcuit thru you to the kicker.

Be sure to use a new sparkplug.

Well, I have tried everything posted. Nothing worked. The only thing I can do know is replace the ignition coil or the stator. The problem is I dont know which is bad. Anybody have any Ideas? Also, where could I purchase these electrical parts? Thanks for all help.

Check the coil and stator resistance with a VOM or DVM. Pull the connection between them to check. Guessing they should have between 2 and 7 Ohms resistance. Zero or infinate would be a problem of course.

If you leave the stator in, you should see zero Ohms with the points closed, 2-7 with them open. If you don't, points or maybe condensor are the problem.

You can hook up 6V DC to the coil to check it. I keep a small lead/acid sealed battery from one of those $10 rechargible 1,000,000 candle power flashlights around for doing that.

You just wire it across the plus and minus terminals and when you disconnect the plus side of battery a spark should jump from the high tension lead to the ground terminal.

Does the MR175 have a rectifier on it?

What I believe is a rectifier on my MR250 is square, just a bit bigger then your thumb, has black white stripe, black yellow stripe, and green wires going to it.