6hp sudden power loss

[mefishalotz]

I was running my '04 6hp Johnson when it suddenly lost power and was running just better than idle at full throttle - like my 6hp suddenly turned into a 1hp. I don't know if something in the fuel clogged up something inside the motor or what. It still ran smooth though and didn't try to cut out. Any suggestions on a fix?

 

[tashasdaddy]

Re: 6hp sudden power loss

did it rev up but not go anywhere, or did the revs drop to a slow speed. did it run hot, when was the impeller last changed. check spark on both cylinders, and compression. then we go from there. also answer the questions.

 

[mefishalotz]

Re: 6hp sudden power loss

The revs were just slower speed. I don't think it ran hot... water was pumping fine. I've never changed the impeller. I've only used the motor about ten times. I popped the cover and checked to make sure the spark plug wires were attached and one pushed on a bit tighter but no improvement. How do I check spark and compression or should I take it somewhere to have it repaired? I was using it on a new 10' trihull boat and it was plowing pretty hard as opposed to getting on top like my old jon boat. I was a little concerned about the strain on the motor so I wasn't running it quite wide open when the incident occured.

 

[F_R]

Re: 6hp sudden power loss

Your motor most likely was running on one cylinder when it had lost power. First thing to do is try new spark plugs. I don't mean to be insulting, but it sounds like you know nothing about motors. That is not a bad thing, but you have to decide if you are going to learn, or get somebody to fix it. That's not a bad thing either. Do you even have basic tools, like a compression guage and flywheel puller and a torque wrench?

 

[HighTrim]

Re: 6hp sudden power loss

You can get a spark checker and compression gauge at any auto parts store, the compression gauge for about 20 bucks and the spark tester for under 10, or you can make your own. remove your plugs and ground them to the block or ensure they are away from it, screw in the compression gauge, crank it over 5 to 6 times or until the gauge reaches its "peak", record reading. Continue with remaining cylinders. Some say to bring the motor to operating temps first to create a benchmark. The spark tester will plug in where your plug does, there should be a strong blue zap!! and it should jump a good 1\2 inch. Let us know what you find.

 

[mefishalotz]

Re: 6hp sudden power loss

Your motor most likely was running on one cylinder when it had lost power. First thing to do is try new spark plugs. I don't mean to be insulting, but it sounds like you know nothing about motors. Do you even have basic tools, like a compression guage and flywheel puller and a torque wrench?

You're right, I don't know much about motors. I agree that it was probably running on one cylinder when it lost power. I'll get new spark plugs (but could one have failed in an instant?) The only tools I have are a couple of fishing rods... guess I'll be making a trip to Auto Zone. I'd love to be able to repair my own stuff. I'm assuming I don't need to have the motor in water to do the compression/spark tests?

 

[waterbuffalo]

Re: 6hp sudden power loss

You don't need to have the motor in water as long as you do not have the
motor running when you are testing for spark. Pull one plug out at a time and
set it on the block and crank engine over. You should be able to see spark.
Do not run you motor without water muffs on the water intake.

 

[tashasdaddy]

Re: 6hp sudden power loss

those small motors, don't like muffs, if you need to run it fill up a trash can.

 

[mefishalotz]

Re: 6hp sudden power loss

I've been really busy but managed to pick up a spark tester and compression tester. The spark was good on both wires and the compression was identical on both cylinders. It built up steadily to a max compression of approx. 110psi after 3 or 4 pulls. The spark plugs had oil and some gunky buildup on them. I took them to AutoZone but they didn't have them. I asked one guy what he thought when he looked at one of my used spark plugs and he said it looked like it was shot and that it must have been old. He also said it looked bent and that it didn't looked gapped right. He guessed that the engine must have been missing but I told him it was running smoothly before it suddenly lost power. I tried Pep Boys, and some other auto store but they didn't have that type plug. I guess I'll have to try a marine store when I get a chance. So what's this tell you guys?