[crashcourse101]

When you say dist sensor are you referring to the ignition module? No, I did not change any internal distributor parts besides the button and yes I replaced coil. I have been stumped on this for a year and 20 hrs on the boat later. It runs great but I wonder if the service bulletin I found was because they put in a 1.65 instead but half a jet size for that many rpm?

I kept thinking ignition too Mikey but I am confused without just throwing parts at at.

[mikeyt]

The distributor sensor is located underneath the distributor. Here's a little information from sterndrives.com

And here are the proper timing procedures at perfprotech.com

[husker_fan]

Valve springs? If it sat for 10 yrs and never rolled over, some of the valves would have been open. These springs can take a "set", and have little pressure at the seat or open. I've seen some race engines I built that sat over winter that the springs on the open cyls were a quarter inch or more shorter when removed. I believe your springs should have around 75lbs of seat pressure. Just throwing it out there.

Sent from my SCH-I535 using Xparent ICS Tapatalk 2

[crashcourse101]

Thanks guys I will keep digging and keep you informed

[Andy b]

How are your risers?
Have you checked the plugs for water/rust?
Have you done a compression test?

The reason I ask is this is what happened to me last month.
Turned out the riser gasket had gone and this in turn did my head gasket!
Hope i'm wrong
Here's my thread
Well that was a long week.

[crashcourse101]

compression is great 150 +/- 5 on all 6 cylinders no rust, black at threads with a great burn on tip with no full throttle stop check. I have a lot of no wake zone to idle through so I am thinking I have a clean condition at idle and a rich condition at wot.

I see yours is a balance shaft too which mine is supposed to be but I am under the impression my motor has been replaced by an older version of the 4.3 non balanced shaft with the same carb from factory so my tuning could be off?

[Andy b]

I'm glad to hear that sir
So your motor is pre vortec then