1986 Ski Nautique Ford 351 Commander (Misses badly under load, great on trailer)

[mbarton]

Had the exact problems, tried everything that you did, no results. Finally found a post on the filter screen in the fuel pickup tube. It is on top of the pickup tube in the gas tank just under the 90, inside the tube. This little screen plugged the tube. I took it out got a ton of **** from the tube. How the engine ran will all this in the pickup tube still is a mystery to me. I left the screen out, have a Racor filter before the fuel pump. Hope this helps.

[RRR]

Ok, finally got the boat out with the mechanics and after a few minor adjustments to the new carb and the shifter cable at the tranny, it seemed to run just fine.
Took the boat out again to have some fun and we did at last. Just got one small sputter and that was it.
Thanks everyone for the posts. I'll keep checking the site.

[surroundsound64]

I'd be looking at the Petronix Electronic Ignition if it was me. Those Petronix units seem to cause much more trouble then they are worth. We put one on our old 91 Sport and it worked great...for about a month. Then the advance would either get stuck advanced (ran like crap when slowing down/idling and would be hard to start) or it would not advance and it would miss badly and not get over about 15 mph. Summit customer service blamed it on faulty spring and sent us a new set which did not fix the problem. After some arm twisting they got Petronix to send us a replacement unit. This one is still working correctly on my brother's boat but I have heard of way more problems than success stories with these units.

Another common issue when adding an EI is that the coil may not be sending the correct voltage because it is going through a ballast resistor from the factory. If the resistor wasn't bypassed when the EI was installed then it's likely the coil is in the midst of dying a slow death and could be contributing to your problems.

Getting a mechanic with a timing light and a multimeter out on the water would help to diagnose your issues.

Shawn, I thought he said they installed a new DUI unit after that.

I had the same issues as Shawn and went with a DUI. Problem solved.

Glad you're up and running!

[Skidave]

OK, what is a DUI (other than something really bad that happens after a few drinks)?

On my 1979 Nautique (351 PCM), I had to play with the timing quite a bit after I installed an electronic ignition. I hit it with a timing light and found that I had to advance the timing quite a bit from what the service manual stated. My guess was because of the amount of hours, the timing chain stretched a bit and the timing was different, but not really off...if that makes sense. I marked the setting after several test runs and never had a problem again.

Dave

[s_kelley2000]

http://www.summitracing.com/search/b...ified-ignition

[SilentSeven]

http://www.summitracing.com/search/b...ified-ignition

Well..I'll drink to that!