Have fuel, compression, and spark still wont run

[28sstony]

78 Johnson 150. Changed the filter, pumped about a gallon of gas into a jug with the primer bulb to check for water and it looked fine. All 6 plugs are sparking on their cylinders and the motor has 105 psi on all 6. The carbs were just cleaned and synched, all 3 bowls are full of fuel and the motor still wont fire. My next move is to try a different source of fuel. I'm on vacation with this thing and completely out of ideas.

Thoughts?

 

[R1racer]

Re: Have fuel, compression, and spark still wont run

Does it turn over..? is the battery fully charged, check your connection from the battery to the starter & starter solenoid

 

[28sstony]

Re: Have fuel, compression, and spark still wont run

Yes it turns over fine. It just cranks and cranks and wont fire. All the plugs are wet so all cylinders are getting fuel, all 6 plugs are sparking on their respective wires.

There was about 30 gallons of 93 Octane left over from when I last ran the boat in August, treated with Stabill in Nov. I added 30 gal of ethanol free 90 octane two days ago.

 

[R1racer]

Re: Have fuel, compression, and spark still wont run

How can you tell if you getting spark on all 6 plugs , Are you using a tester ...?

Spray pre-mix directly to each carb throat , Pull and clean the wet plugs to dry....Give it a try if it fires up on that you might got some sort of a fuel restriction which is possible .

 

[jonesg]

Re: Have fuel, compression, and spark still wont run

Flooded, open throttle to full , crank it until it starts to pop.

Or remove plugs and crank engine to blast it out of the cylinders.

Make sure spark can jump 3/8th inch gap.

 

[boobie]

Re: Have fuel, compression, and spark still wont run

Dumb question on that mtr but how about the flywheel key ? Does the spark jump a 7/16" open air gap on a spark tester? By the way, how did you check your spark?

 

[swflhummer]

Re: Have fuel, compression, and spark still wont run

yeah sounds like timing is off... Bout the only thing it could be if all other 3 rules are as you described...

 

[jerryjerry05]

Re: Have fuel, compression, and spark still wont run

Yea,if you have good spark and good comp.And the fuel is good then the flywheel key might have sheared.
I had a 88/85hp and it was running great.I shut it down and a week later tried to go fishing.NOTHING.Wouldn't start even if I used starting fluid.
I was a new mechanic at the time and checked everything.Finnaly went to the MASTER(boss) he said pull the flywheel and check.I'm thinking the boss isin't as smart as I thought.No way was it gonna be the problem.It was.I looked for 4 hrs.Changed the key and was running in 10 min.
I don't usually say this but try starting fluid.Just a touch.Too much can cause damage.J