1988 70hp ignition testing ?'s

[horiconducker]

Do a linc and sync is it timed right there is a low speed timing for that motor. What is the high speed jet number in the carbs you have. It sounds like your motor runs rich at an idle and clears up as you accelerate.

Ive done the lync and sync per the oem manual. There is a method A (has a throttle pickup timing spec) and a method B ( which is completely different and has no throttle pickup timing spec). My motor uses method B due to the throttle cam it has. Ive tried adjusting the motor to let it have a little more timing before throttle plates open but it runs worse. Runs best set to the factory manual specs for method B. I don't remember the jet numbers off hand, but when I rebuilt the adjustable carbs before i put them on, i checked the jets and they were correct for the 91.

 

[horiconducker]

Well we will hopefully find out later this week, I ordered a new engine wire harness, power pack, and stator. Hopefully i get the parts by the end of the week.

 

[Tim Frank]

I haven't seen compression readings. Have you verified that?

 

[horiconducker]

I haven't seen compression readings. Have you verified that?[/QUOTE

yes 110 to 113 on all three

 

[horiconducker]

Well I received my new wire harness, stator and a power pack. Installed them, checked that I had no voltage on my kill wire, and checked for spark on all three cylinders, I thought I was good to go. Then tried to start it in a barrel. Was really hard to start, once I finally got it running it was missing terribly. Went back and checked all my connections again everything was good. I then decided to try my old powerpack, put that old pack on, turn the key and it started up and ran great in the barrel. Decided to try the new CDI powerpack again and it went back to running terrible. Looks like I'll be calling CDI for a new replacement power pack tomorrow

 

[South Paw]

Well I received my new wire harness, stator and a power pack. Installed them, checked that I had no voltage on my kill wire, and checked for spark on all three cylinders, I thought I was good to go. Then tried to start it in a barrel. Was really hard to start, once I finally got it running it was missing terribly. Went back and checked all my connections again everything was good. I then decided to try my old powerpack, put that old pack on, turn the key and it started up and ran great in the barrel. Decided to try the new CDI powerpack again and it went back to running terrible. Looks like I'll be calling CDI for a new replacement power pack tomorrow

I'm no expert here at all but i have been down this road myself. I replaced my stator, timer base and power pack on my 1982 70hp johnson. The PP was genuine OMC but the Stator and TB were CDI. Check the wiring in the plugs, i don't recall which one it was, ( about 2 years ago now) i think it was the wiring from the stator plug, it was not in the right spot. I had the little tool to push the pins out and put them in the correct location. I guess what i'm saying is check how the wires plug in from the stator to the PP as they came bass ackward from CDI and i had the exact same symptoms you are describing.

 

[horiconducker]

Yes I noticed the brown and brown/yellow wire on the cdi stuff was in different locations compared to the oem. I had called cdi before I installed the parts and they said to just match up the wire colors. After it didn't run the first try, i tried swapping the wire around and it made no difference.

 

[horiconducker]

Just an update, finally got a replacement power pack from CDI and got to take the the boat out yesterday, Runs much better now.