1988 johnson 90hp blowing coils

[thegoose]

I have small cracks appear on the coil of the upper right cyl after only a few hours of use <br />I use the boat very little.Once or twice a year. Tach is also sporadic most of the time does not work. Any relation to the blowing coils?

 

[clanton]

Re: 1988 johnson 90hp blowing coils

Pack output amy be too high. How many coils have you replaced?

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

Clayton thanks for the reply I have gone through 3 coils in about 10hrs total run time. I use the boat once a year going to Canada fishing. When we left the island this year to come in the motor ran fine all week including a morning run of about 20 min. Pulled away from the dock and was running on 3 cyl. When I got back the top right was not fireing.Took lower right coil moved it to top took top coil moved to lower and all cyl fired. Put coils back in previous pos all cyls fired.

 

[clanton]

Re: 1988 johnson 90hp blowing coils

I would clean pack and coil grounds, check/replace sparkplug wires, check pack output to coils, at idle and 3000 rpms All 4 should be same. If motor has 2 packs check diode in pack. A defective diode in one pack will effect the other pack.

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

Clanton thanks again. Would you believe that replacing the power pack on the right bank be likely to resolve the coil problem? Also could the tack not working be related?

 

[clanton]

Re: 1988 johnson 90hp blowing coils

My book shows 1988 as only having one power pack. What is model number of engine? Tach gets signal from charging system. I would not change pack or stator with checking output.

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

Clanton I checked the serial# IT IS 185318 THE motor is stamped 2-19-1987. Sorry I had the wrong year. I have a friend that lives in Crystal River on the golf course east of the air base. Thanks for your comments. I will try to find a way to check high voltage as you suggested.

 

[clanton]

Re: 1988 johnson 90hp blowing coils

You need peak reading to or adapter for mutilmeter to check the output voltage . Stator output App 150 volts, pack output to coil app 125 volts. I lived on the water in Homosassa 7 miles south of Crystal River for about 10 years, sold the house Oct last year, rented for a while just moved into small house will stay here for awhile. Im bout 10 miles NE of Crystal River.

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

Clanton did you see my last reply on the model# of 90 hp Johnson?

 

[clanton]

Re: 1988 johnson 90hp blowing coils

Yes seen last reply, date stamp is not by OMC, The model number is the number to tell year, But if it has 2 packs it is below 88 maby, Spec will be about the same. When you get meter check pack output voltage to all 4 coils should be close, if the output high only on the one with burnt coil, pack is bad. Again I would not change pack or stator without checking output.

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

Thanks again Clanton I have a Fluke Meter the manual shows that I can check voltage with this meter I will do this in the near future. Have you ever done any business with Mastertech?

 

[clanton]

Re: 1988 johnson 90hp blowing coils

No, what do they sell?

 

[thegoose]

Re: 1988 johnson 90hp blowing coils

They sell motors parts and advice.It is a large site. You should take a look.