loosing spark after running a little while

[bob johnson]

the last 3 times out with my boat , the motor died after maybe less than a 1/2 hour of use.

first time i thought it was the old gas I used( maybe coincidence)

then I switched out the gas and took the boat to the ramp at lunch time from work on firday and she finally started and ran great...

took the boat out today before sunrise and ran about 15 minutes to my spot and she died when i throttled down...and started a few times and quickly died each time.

i let the boat sit for about 2 hours. but she would not start, looked like gas was coming out the carb openings when i took the air box off, especially when i tilted the motor way up.

called my mechanic from the boat and he thought i may have flooded it...disconnected the gas line and tilted the motor to get the gas to drain and , later cranked and cranked.... to get the gas out....

but she never started...even after i hooked the gas line back up..

it fired over one instant when I put the throttle all the way up in nuetral to open the butterflys all the way... but died out again

got a tow in.

came home and tried to check it out......checked the spark seemed ok....

she finally fired over when i throttled the motor wide open in nuetral while i cranked it over..


settled it down and ran it for 15 minutes on the muffs...all good

got brave

took the boat out in the afternoon stayed close to the ramp drove maybe 10 minutes and when i throttled down to go to nuetral it died again...

would not restart...left it for 45 minutes and when it got dark, i checked the spark with a tester and had none!!!

so i thinmk i am losing my spark after running a while..and after sitting for a long time 1/2 day or so....It come back to working.

i originally thought it was the fuel delivery....but i think i flooded the motor the today in the early am, when i tried to restart and she had no spark( didnt know it at the time ) and i kept trying to crank it over....

the motor is a 1995 Johnson 115 hp.. looper ( ocean runner) 60 degree with Optical Ignition System.

I have a spare parts motor that runs( has hard knock) that i could take parts off of if need be.

what is going bad on this motor killing my spark????

if there is a pattern that I can tell so far for the three times it died on me, it is.....

after 10-15 minutes under way and at least mid throttle, when i slow down and throttle back...the motor dies..it may restart breifly one or two times and then it is done....

the first time it happend thrusday I was in the middle of the hudson river and it felt like i hit a submerged log , so I quickly slowed...and then the motor died...it restart and I was going again for maybe 15 seconds and it died again..that day later on I thought it might have been the bad gas i used that was 10 months old

now it has happened the next two trips with good gas..

this last time i brought some tools to check things if it happend...and found no spark.

thanks

 

[freddyray21]

Re: loosing spark after running a little while

coils breaking down when they get warm

 

[ondarvr]

Re: loosing spark after running a little while

All the coils don't typically fail at the same time, sounds more like a power pack or some other component that has controll over all cylinders.

Also could be a loose or bad connection, possibly the the kill switch.

 

[tashasdaddy]

Re: loosing spark after running a little while

agree with ondarvr

 

[bob johnson]

Re: loosing spark after running a little while

wow, lost my own thread for a day...my email noticifcation doesnt take sometimes!

well yesterday i went to try the motor again, because somehow it fixes itself after a period of time...well the key did nothing..

could not even turn the motor over...

thought the iginition switch might have died...but since I have another control sitting by on hand I repalced it...still nothing...

the system check runs through its cycle..but nothing happens when i try to crank the motor.

i have voltage to the starter solenoid

the battery is charged

it looks like there are only two pieces that supply the spark plugs each having one bank of spark plug wires. which are mounted on another electrical piece.

this is an Optical Iginition System motor!! OIS

do they still have a coil for each plug??

This motor is a 1995, I also still have the 1997 Evinrude 90 of the same style that i can take parts from to check... even though the motor is under warranty.. supposedly...



I have only about 3-4 hours on this thing since i bought it.

While the both motors are OIS they have different harness plugs and the ENGINE fuse for this one is a tiny 1/2" long inline fuse that still looks good ( the 1997 had a automotive blade style fuse with a big red cap on the holder)

at least as best i can tell.

I might have fried the starter solenoind from so much cranking , to get the motor started.

bob

 

[bob johnson]

Re: loosing spark after running a little while

bump...

anyone have a suggestion to check for why there is nothing happenign when i turn the key now?

I replaced the ignition switch.

.I am thinking the throttle arm switch which makes sure you cant start in gear.... might be an issue to check

and then there might be something on the motor that is killing power to the solenoid or not allowing power to it??

my mechanic cant look at it for a week!!

was losing spark after running, then this no cranking..

battery is charged

i have voltage to the start solenoid( via battery cables)

anyone?

thanks

bob