Inconsistant spark on bottom 2 cylinders? Need some help

[mkeleher]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

so the one new wire that I ordered should read somewhere around the 10 ohms range right out of the rapper?

 

[Dave1027]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

Sounds like somebody screwed up and replaced 5 of the wires with automotive wires.

 

[mkeleher]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

Got 9 ordered which should be here today. I'll report back after the test run today with the new spark plug wires on. Fingers crossed that this fixes the problems.

 

[CharlieB]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

Even automotive carbon core wires should Ohm right around 10 or less per foot. It is after years of use the carbon begins to degrade, the current actually making microscopic sparks between the individual carbon molecules, burning and converting the carbon to ash. Anyone pulling on the wire instead of the boot can break the carbon thread and begin the burning process at that break point. VERY common failure on cars as owners are not very well informed.

Most decent plug wires have an actual small gauge wire wound around the carbon which greatly slows the carbon degradation by acting as a secondary conductor of the high voltage.

Marine wires are usually a higher grade materials, better built, better performance.

 

[mkeleher]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

put the wires on today and motor would not run over 4000 RPM's and was very doggy out of the hole as usual. So at this point I have new plug wires, new spark plugs, a new stator and rectifier which now has the battery charging and the tach working correctly. I double checked today to make sure I had spark with a spark tester from the spark plug wires to the spark plug and I have solid spark on all. Checked compression and I have 115-110 accross the block. What would be my next point to investigate on this motor? I would hate to take it to a tech since I have already gotten this far into it. That would be like raising the white flag. Any help or suggestions would be greatly appreciated.

 

[CharlieB]

Re: Inconsistant spark on bottom 2 cylinders? Need some help

A 2.4 ECU will not run on a 2.5 as fuel curve in mapping is different. Look on the heads and get casting number to see if a 2.4 or 2.5L. Also

You bought what you think is a 2.5 but it has a 2.4 ECU, this could be a serious problem.

The prior owner told you how fast the boat USED to be, what didn't he tell you? What wrong parts he installed?

Verify what you have before you do anything else.

Find the soft plug on the block, make sure that number string is the same as your serial #

Find casting #'s of the block and heads, repost them here so we can make sure of what you are working with.

Also post what prop you are running.