More Mercruiser 350 woes
 

So we had a family weekend this past weekend at my cousins house on Niagara River. I thought I had the boat all sorted out, it's running cool and idles much better with new wires, impeller, engine water pump, ignition control module and alternator.

I had the boat out running like 3500 rims on plane doing 30ish on speedo, I went to open her up and she coughed out carb then stalled....again. This is common with this boat. I was able to get it re-fired and as long as I kept her around 3500 rpm cruising I was fine.

I was able to throttle onto plane and heard the secondaries kick in without hesitation. I thought possibly a fuel filter. I installed a new one and no change.

Then today I was loaded with 6 in the boat and we were cruising around the island. It ran flawlessly until I had to idle for a while past a hydroplane race once I tried to get on plane it coughed then died. I re-fired it right away but it then died, like loss of spark.

I did test the ignition cold and had proper voltages everywhere, but not hot. The only thing I didn't replace was the coil. I also can feel what I think is a slice in the engine harness.

I checked the pins on the engine harness and found a broken one. So....I'm currently looking for a good engineharness in the wanted section.

It seems this only happens when the engine gets hot.

Any help would be appreciated.

Please? Anybody?

I'm spinning my prop going nowhere fast!

Can ya just hard wire past the harness? For the goat and the time I think you could prob make something work. Worst case ya have to get a new harnes anyways.

Could be a distributor pickup.These normally start to act up when they get hot / higher resistance.

I was thinking this. It acts like you shut off the ignition. I'm gonna go try it in the driveway today after it sat overnight.

Thanks guys!!

I have had both pick ups go in my Formula, upgraded to the new sealed style. Beyond that, I have had both coils start breaking down after a bit during WOT runs, at different times of course. With the age, I would upgrade both items as a matter of maintenance. Since doing that I have had no funky running issues at WOT, but did have similar issues as you before that.

What are the part numbers for the upgraded pickups? Also what coil are you running? It seems that a MSD won't work with the Thunderbolt IV module??

take a timing light out and try to duplicate the fault. if you can run with engine hatch up have the light on and watch to see if it goes off as engine quits.

MSD coil ? Sure they will. Been using the High Vibration Coil on several engine's for many years.

Click here: http://www.summitracing.com/parts/msd-8222/overview/

Only reason I went to those both times was because stock coils went bad (old) and both motors had some decent upgrades.

http://static.summitracing.com/globa...e/msd-8222.jpg

BTW, if you ever get nervous about the coil wire coming out of the coil, the below (coil wire retainer) is good to get. Yeh, expensive for what it is, but things like this let me sleep at night and run ballz out during the day. LOL.

http://www.summitracing.com/parts/msd-8217/overview/
http://static.summitracing.com/globa...sd-8217_ml.jpg

^^^^^Thanks!!!^^^^^