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1979 Evinrude 90hpweak spark

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silvershadowmgf

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"I have a 1979 Evinrude 90hp w

"I have a 1979 Evinrude 90hp which let me down in the sea the other day ending with an embarressing tow into shore by the local coastguard. Ive checked the fuel line, and fuel i getting to the engine. i have also checked whether there is a spark, there is, but it is very weak and probably would be put out with compression. I havent got a lot of knowledge on boat engines but im willing to have a go, otherwise ill be selling as spares or repair so i might as well give it a go myself. Can anyone tell me what i need to check/test and how to do it. many thanks, Chris"
 
"Remove spark plugs when testi

"Remove spark plugs when testing for spark. It should jump a 7/16" gap with a strong blue lightning like flame.... a eal SNAP!

Disconnect the large RED electrical plug at the engine, then crank the engine by jumping the starter solenoid (bat terminal to small 3/8" nut).

If you now have proper spark but do not with the RED plug connected, suspect a shorted ignition switch.

If no change in spark, look closely at the stator under the flywheel. If a substance is leaking out of it either at the front or the rear section, replace it. The stator is the beginning of the igniton and charging system.... that leakage results in a voltage drop to the powerpack which in turn results in weak and eventuially no ignition."
 
Surely be disconnecting the re

Surely be disconnecting the red plug on the engine there will be no feed to the coils and thus no spark at all?

As soon as the rain stops i can give it a try!
 
"The ignitioin is self contain

"The ignitioin is self contained, deriving its power from the stator underneath the flywheel. There is no battery voltage being applied to the ignition system on engines from 1973 up. Should battery voltage be applied to the ignition system, that will destroy the powerpack at a minimum."
 
"I have just tried the jump le

"I have just tried the jump lead method, i had no spark at all. tried reconnecting the red plug and again still no spark. So ive gone from having a weak spark to no spark at all?"
 
"re-chg your batt--pull the pl

"re-chg your batt--pull the plugs,and try again...if u have weak spark on all,..most likely,u need a new stator....weak/no spark on one bank,...timer base...intermittent/weak/no spark,on opposite banks,.to a new pwr pack i go..."
 
"The stator under the flywheel

"The stator under the flywheel is the beginning of both the ignition and charging system.

From the stator, the Brown wire and the Brown/Yellow wire powers the port powerpack. The Brown/White and the Brown/Black wire powers the starboard powerpack.

Have a ohm meter set to the high ohms scale. The ohm reading between either of those two wires should be 560 ohms +/- 75 ohms.

Between any of these four wires and ground, there must be NO READING. Any reading here indicates a dead short in the timer base.

However, look closely at that stator under the flywheel..... you may need to remove the flywheel for a accurate look. If there is any substance leaking out of that stator, leaking down on the timer base and powerhead, replace it regardless of what ohm reading you may obtain.

That engine must crank over at least 300 rpms in order to have the stator energize the powerpack. Keep in mind that if you have a slow cranking engine, due to a low battery, faulty starter, loose or tight but dirty cables, the ignition will be weak or non existent even if all else is as it should be.

When time permits, visit my eBay store at: http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"
 
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