Originally Posted by sutphen 30

you run holley efi,right.is there a place for inputting dwell?
short story,I got a tune for a starting point on mefi4b,,little did I know,the tuner had jacked up the dwell 2-3 x more than a stock merc.I'd be going along and the engine would just die.finally stumbled upon that one,,never blew another module.did get good at replacing them while boat was under way.

Originally Posted by articfriends

What was ignition dwell at? Ive seen as high as 15 MS in stock, virgin tunes. Ive lowered them under 5 and engine still ran fine. At 15, the module overheated around 5800 to 6200 on dyno then acted like a rev limiter fwiw, smitty

Originally Posted by articfriends

What was ignition dwell at? Ive seen as high as 15 MS in stock, virgin tunes. Ive lowered them under 5 and engine still ran fine. At 15, the module overheated around 5800 to 6200 on dyno then acted like a rev limiter fwiw, smitty

Originally Posted by sutphen 30

that sounds modified at 15,,all the stock merc tunes I had were in the 3-6/7,,mine were 12-15,,it would cook the module,,merc has a big round rotor w/ fan blades on the bottom,,that helped some.

https://www.amazon.com/dp/B00AJVRHQU...roduct_details

Originally Posted by articfriends

stock 502 mags are 15.38 MS all the way acrossed the board
stock 500 efi is 10.00 MS all the way acrossed the board
Ive actually never seen any stock mercuiser tune thats not 10 or higher.

Originally Posted by sutphen 30

its not a relay,,its a circuit breaker.but yeah,you had some corrosion.

Originally Posted by ICDEDPPL

I got em both started .. port needed the tune reloaded.. seems like RF or something is corrupting the files . Im getting both new distributers,, Eddie young says they give him lots of issues.