1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pack?

[zacklanders]

My 1986 Evinrude 90 HP engine runs good and gets on plane good but cuts out pretty bad about every 5 seconds. I have changed the stator, coils, plugs, plug wires, fuel lines, filters, had carbs cleaned and rebuilt and replaced one power pack. Talked to two shops one told me it was the power pack other told me it was not. Any way to test the power pack. If I switched the power packs from one side to the other would that tell me anything.

 

[SparkieBoat]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

you can get a DVA adapter and a multi meter and test your stator and power pack per instructions from CDI Electronics site. also check all fuel connections/hoses and maybe a good carbs cleaning...replace or install a water fuel separator..

 

[boobie]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

First off get a timing lite and hook it up to each cyl when it is doing it. Turn the timing lite around and look into it. When you see "black spots" that's the cyl that is miss firing and maybe you can narrow it down to which cyls are acting up

 

[zacklanders]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

I don't have a DVA meter and since I've replaced the stator, wires, plugs, and coils should I just buy a power pack. Doesn't power packs go out more frequent than a timer base/trigger. Will the trigger cause misses? The misses seem to be pretty consistent over and over about every 5 seconds and it jerks pretty hard. It started off a few months ago just doing it every now and then and it also felt like i was running on three cylinders at times.

 

[SparkieBoat]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

you can keep changing parts if you want..but a DVA adapter is less than $30 and well worth having..I am sure this will not be the only time that you would ever use it..If you plan on keeping/having a outboard motor and doing the service work yourself this is a MUST have so you can accurately diagnose your or your friends motor problems...I mean the ole guess and change does work...eventually. but cost way more than $30 if you buy just one part you dont need. you said you talked to 2 other shops..did they test your motor or did you just ask them what could cause your symptoms??? so any one who tells you its the power pack is just guessing..it may be..it may not be..I mentioned some other things to check above..add to that checking for water in your fuel, and remember just because some one worked on your carbs does not mean they did it right..I have heard of many people having to do the carbs again after someone else fixed them. get a spark gap tester, inductive timing light and a DVA adapter and multi meter..and you will be set to be able to stop guessing

 

[boobie]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

I'd also recommend an OMC factory service manual. Not Seloc or Clymer.

 

[emdsapmgr]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

As Boobie said, the easiest thing to do is check the firing with an inductive timing light. You can rent one at most any auto parts shop or borrow one from a neighbor. The flashes in the gun will tell you if you have weak firing, no firing, or intermittent firing on each plugwire. Once you know your problem wires, you can swap your power packs and see if the problem moves from one side of the engine to the other. Ignition problems tend to show up when the engine heats up to normal operating temps. That's when the weak ignition components tend to break down.

 

[metriccrescentwrench]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

I had a similar problem, turned out to be the timer base. With my engine I could see an occasional miss on 5 out of 6 cylinders with a timing light.
HOWEVER, as others have said, don't just go blindly changing parts. Get a factory service manual and go through the tests outlined there.

 

[CharlieB]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

Need more information on this 'cuts out about every 5 seconds'

idleing, in gear, at mid-throttle, only at WOT?

If this only occurs at WOT try adjusting the shift cable a couple of turns as a stretched cable may not be holding the shifter fully into gear.

 

[boobie]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

It still sounds like an ignition miss to me, not a g/c problem. If it was the g/c you'd get a good clunk.

 

[zacklanders]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

Thanks for all the good info and tips. I'm going to get a timing light and adapter today. The miss happens at all speeds while in gear. It used to do it only after it warmed up now it does it even when its cold. I have replaced all the parts except for one power pack, rectifier, and the timing base. I think its either the timer base or power pack I think the timing light will tell me which one. Thanks Again

 

[mkay]

Re: 1986 Evinrude 90 hp Boat cuts out or misses while running. Could it be a power pa

The ignition system in these engines runs off a pair of trigger coils on the stator stack. These coils produce a high voltage to charge the Capacitor in the CDI system. There is a separate trigger system inside the stator which causes the CDI pack to fire at the correct time to send capacitor voltage to the correct coil. There is no need for a distributor. This system can be checked to make sure that they are producing the proper high voltage. If the charge coils or the signal pickup system misfires the engine will miss. There are two sets of magnets built into the flywheel one for the stator to charge the battery, which is used only for starting ,and the other in the hub of the flywheel to induce the trigger signal to fire the CDI and produce a spark. They are separate. If the trigger system is missfiring there is a possibilty in some engines to adjust the gap between the high voltage spark coils and the flywheel magnets. If the gap is too wide that cylinder will missfire. Evinrude produced an inexpensive gap gauge to set the proper gap. Adjusting the gap can be an inexpensive fix. Good luck.