Snowmobile Repair: timing, polaris 340, spark plug wire


Question
i have a 1977 polaris 340 cc cobra that will not start, only backfires through carb and exhaust.
engine mod:ec34pm04 fuji How do i check the timing or is this really a carb problemb

Answer
To check the timing there should be a eye glass hole next to the recoil housing. You'll need a static timing light. You need to hook this up to the #1 spark plug wire and then run the machine at about 1200 to 2600 rpms. Using the gun you should see a mark. It should be in the middle of the hole. But since your machine isn't running you'll jave to pull your recoil housing off and then you magneto. under all this is your timing plate. You'll need to check to make sure it hasn't moved or is damaged. You can move this plate clockwise or counterclockwise to advance or retard your timing. Then yuou have to put it all back together to check it. Are you sure you spark plugs are still good?