Mercruiser 3.0 won't start after ignition upgrade

I am hoping that someone may have an answer to this dilemma.....
I'll start by explaining what has been done first.
We decided to upgrade our ignition system to the Delco EST ignition system. The boat is a 1986 and has a 140hp Mercruiser I/O Alpha one and we just got sick and tired of replacing ignition parts all the time and also wanted something more reliable. Boat ran great last summer and we winterized it and shrunk wrapped for the winter. In early summer we decided to get it ready for the water. No a big surprise it didn't want to start so before we bought all the annual parts we just bought the new ignition system. Installed it according to directions in the retrofit manual. In the beginning we measured the voltage at the coil and it was 12.2v so we didn't think that we needed to remove the resistance wire. Got it all wired in and put together and the boat didn't start. We went through trouble shooting several things. But found we had 11.5v at the end of the coil wire going to the distributor with the key in the on position, when cranking it dropped to around 7v. We also had zero spark on any of the plugs.

So after reading as much info as we could find we tried a couple things. We removed the resistance wire and ran a straight 14g copper wire straight to the new coil. Also found that several people had problems with the tach, so we disconnected the tach. Sure enough we were now getting spark but the engine still won't start. It acts as if it is trying to start and then there is a big puff out the carb/flame arrestor then it just cranks over again. We made sure that in putting the distributor in, that the #1 cylinder was at TDC aligning the notch on the crank pulley with the zero on the timing tab. The spark plug wires are set in the correct firing order as the rotor turns clockwise of 1-3-4-2. The carb was cleaned and rebuilt, getting plenty of fuel and the pump was converted to electric a couple years back and runs good and strong, fresh fuel as well. I am not sure quite how to fix this if it just some tweeking on the distributor or if we are completely off on the timing.
New parts: EST electronic ignition coil, new distributor, new plugs, new plug wires, rebuilt carb and fresh fuel.

So basically the question is what are we missing so that we can get it to run

Any thoughts or advice is welcome.

Re: Mercruiser 3.0 won't start after ignition upgrade

OK we got her to start after some "tweeking" and to keep it running we had to advance the distributor now we are going to proceed with timing. As this is a going to be a first for me and my husband.

Re: Mercruiser 3.0 won't start after ignition upgrade

Sorry we missed your first post, but fromthe sounds of it you may have put the distributor in 180 degrees out at first. With it spitting through the carb this would be the most likely culpret. You were correct in removing the resistor going to the coil, it is used only with points.

Re: Mercruiser 3.0 won't start after ignition upgrade

That is possible. We had 2 issues to sort through. One was a bad tach and the other was the resistance wire and small one human error. After reading the firing order a dozen times and it even being on the valve cover, I managed to transpose the 3 and 4 wires. Caught it and it fired right up running smooth. Got the timing all dialed in and the boat has never run this good. Took it out to the lake for a test run and everything is great. Very happy with the upgrade.
I appreciate you responding but we were able to figure it out and sometimes it's a good thing because it really helps you learn. I have found a lot of great information on iBoats and love this forum to help find answers to my questions. Had I not read a previous post by someone who was experiencing similar problems it would have taken longer to diagnose and fix. Thanks

Re: Mercruiser 3.0 won't start after ignition upgrade

SOunds good, glad your up and going