Vintage Dirt Bike Q & A

Hi, new to this forum and i have a spark problem with a MR50 that has been sitting for years. When I started cleaning it up I had spark but notice that there was greasy dirt in the points area so I sprayed electrical contact cleaner through the flywheel slots and blew it out with compressed air. Now i have no spark, I removed the flywheel and the stator pale to look at/clean better, and find no bad wires but still no spark. Does anyone know the resistance that I am suppose to get from the stator coil. Thank you for the help.

I dont know if you figured out what is wrong yet , I have a manual and I dont see anything in the service manual, it only says to check the continuity at the stator coil. Have you tried to adjust the points? and i would assume you have double checked all connections. I would adjust point 1st and try to see if I get spark with a new plug.

thanks for the response, i have checked and double checked , the plug wire from the coil was in bad shape so i bought a new coil when I get it I will start over.I will post the progress or lack there of.

installed new coil, checked connections still no spark

I dont know anything about your bike so i am just guessing.

I assume the flywheel is still good. Does it have a condensor and if it does have you checked it.

I'm just going on a magneto fired ignition. Have you tried a different spark plug.

another possibility is bad kill switch or bad ignition switch. The only other thing is check the ohm/continuity of all wires in the ignition circuit. hope you get it figured out.

Ok I would check the kill switch buy not pugging it in, leave those two wires unplugged.
This is a simple system point and condenser, you recieved a new Condenser attached to the coil
I would make a guess that it is in the points have you tried to adjust them at all ? I wouldn't think it would be the rectifier. as it all seems to have started after you sprayed the points with contact cleaner. if you have a little emery cloth try slipping in between the points and pulling it out once or twice and see that at least gets you sparking.

Pull fly wheel again and clean pick up at the stator and flywheel as well to make sure you are getting good pick

IF.....IF ....all you did is spray contact cleaner on the points AND it DID have spark before that...then I would use a fingernail board or something equal and simply file the points to clean them.
I had a friend that put in brand spanking new points in his Elsinore and .....no spark. He called me I told him to do the same as above and poof...spark.

Good luck.

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1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

So did you get the MR running?