1990 Evinrude 150 STILL DROPS #4 and #6

[brewhaha]

After running to full operating temperature it drops #4 and #6. It will not run over 3500 rpms in gear like this (in the water). If I goose the throttle a few times it starts running right again. I have other posts about this but they are to long. I have put some bucks into this problem but I still don?t have it whipped.

Decarbed Motor
Replaced leaky / Cracked VRO pump
Cleaned / Serviced Oil Tank
Rebuilt Carburetors
Replaced fuel check valves on intake, purged and cleaned hoses
New, correct, and properly gapped plugs
New Plug Wires
New Ignition Coil Packs CDI
New Stator CDI
New Power Pack CDI

It's putting me in the poor house and it still don't work. Should I keep trying or just sink the ###** thing in the middle of the lake! (just kidding, but i am frustrated with it.)

Ideas???

 

[brewhaha]

Re: 1990 Evinrude 150 STILL DROPS #4 and #6

It does the same thing with the rectifier disconected so the only thing I can figure is the timer base or a weak flywheel magnet maybe. I am out of Ideas. Is a DVA meter the only way I can test the trigger base?

 

[emdsapmgr]

Re: 1990 Evinrude 150 STILL DROPS #4 and #6

A peak-reading voltmeter is a good tool to check the trigger. I think the V6 engines call for output of something like .3 volts when cranking.

 

[Fl_Richard]

Re: 1990 Evinrude 150 STILL DROPS #4 and #6

Is is possible that SLOW is kicking in thinking it's overheating?

 

[brewhaha]

Re: 1990 Evinrude 150 STILL DROPS #4 and #6

The trigger base, it's the only thing left.. Should I get one?

CDI?s troubleshooting guide says to ohm between the white wire to the purple, blue and green in plug one. Then it says to ohm the same white to the purple, blue and green in the second plug. I am assuming that these are the triggers for the individual cylinders with the white wire being common to all of them. It says that I should get the same Mega ohm reading on all of them (between one and five). Four of them are around 1.5 and the other two are 15-to 25-mega ohms. I guess this means the timer base is my problem? Two triggers have a messed up reading and two cylinder don?t fire. What do you guys think? I am a thousand dollars or so into to this now, I just want to fix it.

 

[brewhaha]

Re: 1990 Evinrude 150 STILL DROPS #4 and #6

Well, I changed the timer base last night and it ran good on the water hose so I took her to the lake this morning. In a word, SMOOOOOOOOOOOOOOTHHHHHHH!!!!!! It ran great, smooth as a kitten on idle and like a rocket at WOT. The timer base was the problem the entire time but it has a new ignition system now because that was the last thing I replaced. That?s ok though, at least I have spare parts for the next time and peace mind when turn that key on the water.