Motor or Prop problem; Viking, Force 120 hp (1995)

[alvez]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

its a 20ft viking. weights 1900 lbs.

 

[jerryjerry05]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)




What prop?Pitch?

Running in a tank with a testing wheel and it gets 5000rpms?
Then your prop and it gets 3000???

Need to do another compression/spark test.
Get a spark tester that measures the strength of the spark.(see pic)
Weak spark will show under a load.In a tank with the wheel it might not.

The fuel system,check it for loose connections,fuel pump diaphram for holes.
The hoses for soft/mushy spots(Ethanol)connectors for sucking air.(see pic)
The connectors in the pic are famous for leaking and sucking air.

 

[alvez]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

Thank you appreciate the input.
I just put a new flywheel and stator. Could the spark still be an issue? What about the prop. isent there service manual for the prop recommended size for my boat? I think thats odd that this information isent available.

 

[emoney]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

I think you and I have similar weight boats. I have a '95 Force 120 on a Trophy 1802 (18'). Mine might be a little bit heavier. Anyway, I currently have 19p prop and I'm getting around 4800ish WOT. Do you know what's on there now?

 

[alvez]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

The prop on my boat is 17 pitch prop, it works out to be a 13 1/4 in diameter. I seen the boat man today. He's going to rebuild my carburators, the internal working were gunked up, expecially the lower one he said! So lets see what happens after that. i hope that solves the problem.
.

 

[jerryjerry05]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

That prop is probably the right one.
Again??? WHY ??? didn't the first mechanic figure out this stuff????

 

[emoney]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

Yeah man, Jerry is definitely on to something here. How in the world does the "mechanic" get the thing to run 5krpm with badly gunked up carbs and you can't? It might be time to start shopping for a new mechanic, or order a Factory Service Manual and get to know your motor a little better. Under the "burn me once, you burned your buddy" clause, at some point this becomes a self-imposed issue. Good luck and I hope this time it solves the problem.

 

[alvez]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

Well guys it wasn’t probably the best troubleshooting I’ve experienced, so I just look at it as preventive maintance. At this point they should replace the fuel pump diaphragm? And we'll call this a major tune up! @. The flywheel and stator? from what I observed they were damaged, magnets were broken up ect,ect,ect.. So if I look on the bright side, when I am out in pacific 20 miles or so. I don't need to be too concerned about something else breaking down. Because funny enough it’s all been replaced!

 

[alvez]

Re: Motor or Prop problem; Viking, Force 120 hp (1995)

I got my boat back from the boat doctor. She ran good. all the way full thorottle 4800-5000 rpm 40 miles per hour. i wanted to trim it out more. but there was a speed limit at the lake. it ran good. thats all that matter and i m glad i thats over with.....