2.4 Bridgeport Losing Power

Hi Randy,

I recently found the IHR website, enjoy checking out Tech Talk, and have picked up some useful tips.  Here's my problem:

Just recently put my Voyager in for the first run of the season (very late start, the Allegheny River in Pittsburgh stayed high with lots of debris). I've run a carburated 2.4 Bridgeport for years.  The engine ran great for the first 10-15 minutes at various RPM's, then I lost power.  The engine still ran, but I dropped off plane, and couldn't get going again at much more than high idle.  Being the first run of the year, I figured fouled plugs from winter storage seal in engine and stabilizer in gas tank still burning off.  Went back to my dock, put in new plugs (NGK BUHW) and topped off with 94 Octane fresh Sunoco land gas.  Engine starts and idles okay, but no power.

Thinking it might be a switch box, I pulled the boat, put the engine in a makeshift test tank and started it.  Using a timing light, I see all six cylinders fire at idle.  The strange thing is when I rev it up, one bank  (all three cylinders) cuts out at approx. 3000 RPM.  The bank that cuts out is the right hand side looking from rear, cylinders 1-3-5, inner switchbox. I don't mind spending money on electronics, but I've heard horror stories of spending a fortune trying to diagnose and putting on new parts that don't solve the problem.  My brother had the "good" switchbox (same P/N as mine) from replacing the pair when one went bad on his 200 Mercury last year, so I swapped it with the inner box, same problem.  I then swapped again, so my original boxes are now back on, but inner/outer were reversed.  Same problem. My local outboard mechanics are willing to offer advice, since they're really too busy to work on it anyway. At their suggestion I flipped the 5-6 coil to see if that changed the problem: it didn't.  1-3-5 continue to cut out over 3000 RPM.

It seems I'm down to the trigger or stator, unless the switchbox(es) could still be the problem?  A high speed spark advance module is shown in my Clymer manual for some V6 engines, but I don't physically see one on mine. Everyone seems stumped by the fact that engine idles on all six, but cuts out on three.  They think a switchbox, trigger, or stator should either work or fail.  Maybe you've run into this problem.  Again, I'll buy new boxes if I need to.  I just hate to shell out the bucks and find I still have the same problem, and need to spend more.

Sorry for the lengthy explanation, but I'm hoping I've eliminated some possible problems.  I'd really appreciate any advice or additional tests I can perform.  I have a trigger (used and good, but replaced incorrectly by a mechanic trying to fix what turned out to be a bad stator) on the way from a friend.   Hoping you can help point me in the right direction.  If you need any extra info. let me know.  Thanks again for your time and help.  I'm sure this is a busy time for you.

Looking forward to getting back on the water.
Luke Mattocks



I like the detailed message. It helps with the recommendation. It's the Stator. It has a low speed and Hi-speed charge coil and the Hi is dead to one switch box. The fact it works at idle rules out the switchbox, triggers, or the coils. Stator it is!




Please submit whatever questions you have to IHRTechTalk@yahoo.com.  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Mark C.


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