1989 Johnson 150 hp cranking, but not starting

[Caudfish15]

Hey, I have a 1989 Johnson 150 hp that ran fantastic when I bought it a week ago. I've run it a couple of times with no problems, but then I had some trouble. A mechanic noticed that the VRO was leaking fuel, so I had him convert it to a regular fuel pump so I can just mix my oil in. After picking it up the motor will not start, but cranks well. I've tried trouble shooting and found that at times I'm getting no spark, but others there is spark. Changed plugs replaced one bad coil, but couldn't get the thing to fire up...when trying it'll crank, crank, crank, and crank with an occasional backfire. Any ideas on what I'm looking at here?

 

[Caudfish15]

Oh and compression was 85, 80, 80, 80, 83, and 82. Mechanic says that's ok for this motor. I expected higher, but ok. Pretty consistent.

 

[boobie]

Go to cdielectronics.com. They have good trouble shooting procedures.

 

[Caudfish15]

My buddy and I used a some kind of manual to trouble shoot. He's more experienced and his end result was that he's 90% that the power pack is going bad. Is there a chance that it's sending power to some, but not all coils when trying to start it?

 

[boobie]

Yes, but it's just guessing not testing. Try replacing it and see what happens.

 

[Caudfish15]

He ran some test on a lot of things to test the voltage and spark, but he was saying it everything else was good. He's not quite sure if the power pack was putting out what it should or not. That's why he was only 90%. He was saying when it backfires it's because not all of the cylinders were getting spark which is more than likely the power pack. I'm not very experienced, but I've learned a little bit. This is my first boat and it puzzles me how it could run great then just go bad all of a sudden. Before replacing the VRO with a fuel pump the only problem it had was wavering at full throttle, then it started stalling out once it got hot. The VRO was leaking fuel pretty good so a mechanic said the pump was bad, but now it won't fire all together. I'm a new member on this site hoping to learn more myself, but I don't have any tools to test with so my buddy is my guy. I'd hate to replace the power pack if that isn't the problem. I'd think that it would run fine now that it's getting gas and oil for sure now. The VRO was also leaking oil after I took the part home I noticed that oil leaked when I pushed on one side of the pump. It's pretty frustrating that the best thing this motor did was start at the turn of a key and idle forever and now I'm getting nothing. I've read a lot of other post and would appreciate some good info. I believe he did bi-pass the shut off switch and had the same result. How would I find out if the motor is a 60 degree or 90 degree? The fuel pump the mechanic put on is a 60 degree. If not the power pack what are my options? I replaced the worst looking coil, the others have some cracking, but tested fine. Spark some of the time, but not all doesn't make sense to me.

 

[Caudfish15]

Any input?