1987 Johnson 90 VRO I can't get it to run

[Basswood36]

Hello and thanks in advance to whoever is kind enough to point me in the right direction. Like the title says. Motor ran great then while traveling at WOT it lost power and it started running on 2 cylinders. It was pumping water so I limped back to the ramp. I unplugged the spark plugs on one side of the motor and tried to start it. No luck. So I plugged those back in and unplugged the other side of the motors plugs. Tried to start it and it fired up. My conclusion was I lost a power pack. I got a new one and installed it. I checked the spark and it is firring nice. Try to start the motor and it barely starts and at idle it runs a few seconds and then backfires. Sometimes it keeps running untill it backfires again in a couple secounds. Sometimes it will make it to the 3rd or 4th backfire before stalling. I sprayed gas in the carbs and it does the same thing. I am thinking elecrtical. But I am stumped. I did a compression test and it is 115 in all cylinders. I do NOT use the VRO system. I use premix. I am going to check the gap on the plugs and after that I am out of ideas. Can anyone get me on track please. Thanks again!!

 

[tassie ben]

Re: 1987 Johnson 90 VRO I can't get it to run

Not too experienced but...does this motor have points?? or is that what you mean by powerpack(i assumming that is the coil)? The points could be cactus.
Just an idea...good luck

 

[tassie ben]

Re: 1987 Johnson 90 VRO I can't get it to run

doh! You said the plug was firing nice...silly me..anyone else have an idea on this one?

 

[zenchal26]

Re: 1987 Johnson 90 VRO I can't get it to run

could be a coil?

 

[Basswood36]

Re: 1987 Johnson 90 VRO I can't get it to run

Are there more than one coil? If so how do I locate the bad one?

 

[jonesg]

Re: 1987 Johnson 90 VRO I can't get it to run

Mine is a 150 so I can't help there but wouldn't a service manual help here? or at least look it up on the BRP exploded diagrams online.

One coil for each cylinder, swap known good for suspected bad and re-test, if it fires up then the coil is bad.


http://epc.brp.com/login.aspx?ReturnUrl=/Default.aspx&AspxAutoDetectCookieSupport=1

 

[tashasdaddy]

Re: 1987 Johnson 90 VRO I can't get it to run

back fire, possible the woodruff key in the flywheel/crankshaft has sheared. this throws the timing out. time the get a harmonic balancer puller, grade #8 harden bolt to fit the hole in the flywheel, and pull the flywheel. you have to use a OEM woodruff key, hardware store ones are not hard enough.

 

[Basswood36]

Re: 1987 Johnson 90 VRO I can't get it to run

I used an inline spark tester and all cylinders appear to be firing . I have to get a socket to fit the bolt on top of the crank to check the woodrift pin tonight. Any other thoughts if that is not it? Thanks again this site rocks!!

 

[Basswood36]

Re: 1987 Johnson 90 VRO I can't get it to run

is there anyone that knows how to bench test the stator with an ohm meter? I need to know what the readings should be. Thanks

 

[tashasdaddy]

Re: 1987 Johnson 90 VRO I can't get it to run

http://www.boatpartstore.com/page33.asp

 

[Basswood36]

Re: 1987 Johnson 90 VRO I can't get it to run

Woodrift pin is good. I can get it to start in Neutral and it will rev up but when I put it in gear it bogs and dies. Also while wot in neutral it skips.