Discussion in 'Engine, Fuel and Exhaust' started by John Lee Penn, Apr 8, 2010.

  1. John Lee Penn

    John Lee Penn New Member

    Iam a newbe at this site so please excuse me if this is the wrong place for this type inquiry.

    Harley Davidson problem.

    It is a 1988 Lowrider basically stock with Screaming Eagle ignition.

    After the bike sits for awhile, a week or so the problem seems to be worse. If it is ridden every other day or so the problem does not occur as often but it still happens. On start-up one cylinder starts firing then as it warms the other one kicks in. Seems to run OK but may have a very slight bobble miss but not all the time. Get on the bike and ride maybe a half hour or maybe all day and not have any problem then all of a sudden one cylinder drops off may backfire and then go on or may loose other cylinder and power and stop running. Have down shifted and dropped the clutch and it start right back up then go on like nothing happened or may not start and just coast to a stop. Hit the starter and it fires up and may run fine or may go ten feet backfire and die. Continues this for as long as it wants to then starts running fine and you may go 100 miles without any further problem or you may go 10 miles with stopping and restarting. It acts like it gets power then stops and bucks a bit then goes on something like running out of fuel but this occurs even with full tank. If you twist for acceleration when it kicks in of course you bolt ahead. I am sure it is an electrical firing problem but don’t know where to start. Also someone said it could be a low oil shut-off switch but it is full of oil and unless this sending unit is bad that makes no since to me. Please Please HELP. Have had this happen at 10 MPH up to 85 MPH and believe me it is no fun on the Expressway.
  2. glider

    glider Veteran Member

    I would start at the wiring on the coil and verify it's integrity too and see if you see any hairline cracks in the housing. From there maybe a new set of plug wires and possibly plugs may solve the issue. Try to determine which cylinder is cutting out. Maybe even check the tips on the plugs where the wires snap on to see if they are loose.

    Not a problem like a low oil shut-off switch on a Harley.

    Lastly suspect the SE ignition module or the harness that connects to it as the source of the problem.
    Try some heat or cool the module with some freon (keyboard cleaner can held upside down) to verify it's integrity.
  3. maine-e-axe

    maine-e-axe Junior Member

    Next time it does it, with the switch still on check with a multi meter to see if you have power to the coil, I've seen ignition switches act the same way your talking as well, wiggle the ignition switch when it starts to die out to see if it will come back on.