1. D

    Mercury 240hp EFI M2 Jet Drive Surging

    Hey I have an issue with my engine surging, hope someone can point me in the right direction. I have a Mercury 240 M2 Jet Drive. It starts up fine but when I put more throttle to it, it starts to surge. When I have it in the water it is a back and forth motion. I do have new spark pugs in that...
  2. Cwescott

    Trying to get 2001 Sea Challenger with Mercury M2 EFI running!

    Bought the boat for really good price knowing it was going to need some TLC. Had a blatant fuel delivery issue as fuel was pouring out of throttle body. Pulled apart and found lines going into fuel rail were disconnected and a couple other little things inside that lead me to believe someone had...
  3. D

    240EFI low idle/major smoke/won't start when warm

    Hi all, So I've done a bunch of searching on this on the forums here, and I've found a lot of info, so here's what I have going on.... So I have a 2001 Challenger 1800, that had a blown engine when i got it. Replaced with a reman short block in 2008. Was running well after rebuild.....only...
  4. B

    Merc 240efi rebuild - spec clarification required

    Hi All. My Merc 240efi Sport Jet would not start. Traced to low compression on #6 cylinder. At strip down I found #6 piston crown missing a piece and the barrel scored. Decided to rebuild the complete engine. I have had the block bored out to 0.015" O/S on all cylinders. I am using the WSM...
  5. Scott Martin

    Big chunk of magnet found wedged next to flywheel. Broken Flywheel or Stator?

    So I went to start my boat tonight only to have this grinding noise when the starter was engaged. Upon closer inspection I found a chuck of magnet wedged on the side of my flywheel. :redface: The chuck is roughly 2 inches wide and about 1.5 inches tall. Needless to say I'll be pulling off...
  6. johnhibbs

    Mercury 240EFI hard starting warm and gas mileage

    I had a hard time restarting my Challenger 2000 with a Mercury 240EFI engine when it was warm. After reading that other people had solved the problem by replacing the temp sensor on the engine (passenger side) I gave it a try and it fixed the problem. Short story: The insulation on the...