1989 Evinrude 48 Spl coil question

[69starcraft]

I think I have narrowed down my surging issue to a bad coil...

question: the 48 has 1 coil for both cylinders (i mean its two coils, but its ONE unit)

I have ordered a new one....it won't be here for a week

meanwhile i have a 1974 50 hp Evinrude Parts motor (if you need parts from that or the 1976 70hp rude PM me)

The 50 has two individual coils i know are good....the connections are the same as my 89, except they are two seperate coils

can I wire these in temporarily so I can go out this weekend? each coil has a trigger and a spark plug wire....same as the 89 except the 89 mounts up different

If I ground it right and connect the triggers and the plug leads i should be ok right?

thoughts?

 

[Monte1961]

Re: 1989 Evinrude 48 Spl coil question

I would think so. Try it and see what happens. Post results for future if someone else has same issue.

 

[69starcraft]

Re: 1989 Evinrude 48 Spl coil question

Well i answered my own question

since the replacement coil is 4 days out (shipping) and I had the 74 50 sitting here I pulled the coils off and wired them into the 48 spl

they fit fine...look a little funny but cover still shuts, and no modification was necessary

runs fine in a bucket....next step is to go to the lake and see if it solves my wot surging issue

I am leaning towards coils because last time I went to do a load test on the lake the motor ran fine for over an hour....just as I commented on its performance WHAM she started surging... those symptoms point to thermal breakdown on the coils.....since the problem seemed to be intermeittant and seemed to surface after motor was warmed up


going to load test hopefully this afternoon or in the morning....

but the single coils from the old 50 wired right in if anyone ever needs to know this info


dave

 

[69starcraft]

Re: 1989 Evinrude 48 Spl coil question

Took it out for a quick lake test.. right off plane she bogged out and ran horribly. Sprayed a 50/50 mix from a spray bottle once in each carb while wife had it at wot...results were mixed...at first spraying it seemed to get it to catch. it started to pickup, then bogged out immediatly. Spraying more fuel did not help the second time.

idled back to the launch without issues...ran smooth. atempts at WOT on the way back produced what this time felt like a rich condition...no erratic surging this time. but bogging out, no rpms

changed coils
plugs
broke down carbs at least three times already. going to pull them again today...
fuel lines are new. I am going to install a filter today on the main line, and two small filters on the carb lines.
I will also change out my fuel pump which I believe is fine, but I have two newer spares that I know are good so i figure what the heck

Any thing else I can check?

this is very frustrating, i am sure it is a simple fix, but can't really pin point what to fix.

 

[69starcraft]

Re: 1989 Evinrude 48 Spl coil question

So I broke the carbs down yet again...

at this point they are so clean that the queen of england could use the bowls to serve pudding in (as well as the rest of the carbs)

I have cleaned every orifice and jet in the darn thing... i installed a big fuel filter on the main fuel line, and even went so far as to install two more mini inline to the carb fuel filter (from weedeaters...brand new) the gas is fresh and the battery is new and fresh. the carbs were not even nasty to begin with like other older motors I have restored without issue

re-assembled everything and fired up in a large barrell. once again it starts immediatly, and idles well. i didled with the idle adjusts, brought each carb down to "chuff chuff" and then backed out about a quarter turn...tachometer shows about 1100 give or take but steady

Goosing it with the cold start lever produced mixed results...sometimes rev was smooth, sometimes felt a little rough, but couldn't hold high rev long enough for it to smooth out (fear a runaway of course)

i've replaced the fuel pump, all lines, added boo-coo filters, cleared and checked vent line....load test proved that gas spray from bottle nor squeezing bulb helped.

I've replaced the "dual coil" unit with a pair of single coils from a 74 rude 50hp and it was not the issue. Compresion on both cylinders is 125+ and equal to both cylinders.

I also checked voltage at the battery (fresh/new) and got 12.65 with engine off...fired up motor and at idle reading was the same...turned on bilge, nav lights and radio (small, no real amp draw) and reading was the same...not sure i have enough "load" to tet with whats installed in the boat....

whats the normal reading for this motor 13.5 or 14.5 like a car?

I've searched and searched under "bogging" and etc but I am still stumped. I like to think of myself as a mechanic, and can remove and break down the carbs on this motor in under 20 minutes....but i'm just stumped...

So it must be electrical....but from my searching/reading it could be either power pack or stator

unfortanatly, having dyscalculia, using the meter for mor advanced things than 12v and simple ohm test (shorts) what i have read on testing these two components requires ore advanced tools than a multimeter and more advanced skills

at about $100 each I a trying to avoid ordering the one i DONT need

help?

 

[bdd]

Re: 1989 Evinrude 48 Spl coil question

Hi there, Any luck with this?. I'm having the same issue? Mine is a 1996 48 spl. Carb's are squeaky clean. Idles fine but; bah bah bah when I give it some rpm's..