93 johnson 140hp no power

[Johnsonblaster]

I have just bought this boat and motor and am very leary of this motor running properly.I have been playing with trying to tune it up and thought i had it running good.It ran ok but i thought that my friend's 120hp had more get up and go off the line.He has a 19 pitch prop and i have a 17. I used to be able to get it up to 55 on the tack at 3mph. Something happenedafter i ran it at with the last fiddling.It seems that it runs best with 6 1/2 turns out in the idle mixture.Is that normal??I ran it at 2 1/2 but got the heat warning after i idled it for 15 min.Now i have no power when i open it up. It surges like crazy. I took a plug wire off one at a time and all cylinders are still working. what's up??<br />confused..

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

That should have read 55 on the tach at 43mph

 

[JB]

Re: 93 johnson 140hp no power

Your carbs need to be cleaned and readjusted from scratch, Blaster. Also check out the link 'n' synch. between carbs and ignition timing.<br /><br />Red sky at night. . .<br />JB

 

[JB]

Re: 93 johnson 140hp no power

OOOPs! Run a compression check first. Over 100 on all, not more than 10% difference between top and bottom psi.<br /><br />Red sky at night. . .<br />JB

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

All cylinders were all 115lbs compression in the beginning of the year.

 

[JB]

Re: 93 johnson 140hp no power

And she was running good at that time?<br /><br />Standing by. . .<br />JB

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

Latest update. I put on the water muffs.#3 cylinder doesn't change tone when i take off the plug wire.I swapped coils with #1 and still no life in #3.There is no misting in front of the air horn.I looked inside and what i could see the reedvalves(or whatever it is called). It looked ok.WHen i put my hand over the air horn i got gas like crazy.There is spark (maybe not as strong as #1)I removed the drain screw fronm the float bowl on #3.There was lots of gas.I just took out the carb and will see what it looks like inside.There was 110 lb compression on #3.It did work ok at the last setting. Something changed all by itself. Maybe the powerhead.<br />Keep you posted.

 

[finnaddict98]

Re: 93 johnson 140hp no power

Make sure you are getting AT LEAST a half inch distance of spark when you check that wire. From experience, I lost number 3 cyl on my 200 hp OMC..did the wires, plugs and coils and it WAS the power pack. Ran abt $300 for the part..thank god for warranties....a little spark is NOT a good thing..a half inch of spark is a good spark.

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

I just cleaned out #3 carb and still no life in that cylinder.I did a check and there was about 6 lbs of fuel pump pressure at that carb. <br />I don't have a strong spark on #3. I swapped coils and plug wires and still the same on #3.I think it's to the mechanic time since i have no way to check the powerpack.

 

[Fouled Plug]

Re: 93 johnson 140hp no power

Have you already eliminated a faulty spark plug from the problem?

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

I have tried a new plug. I have swapped coils and wires. Tonight i tried a new powerpac. Still the same problem.<br />I think it is to the boat shop tomorrow.

 

[Johnsonblaster]

Re: 93 johnson 140hp no power

Do you believe it!!!!!!! I was talking to a mechanic and he gave up a secret!!!<br />I was working on the wrong carb.On this motor the intake manifold is a crossover .THe carb for #3 cylinder is in <br />front of cylinder #4. I changed carbs with #1 and #3 ran perfectly fine amd #1 was dead. I removed the carb and cleaned it out.It looked good <br />but must have been dirty. All cylinders worked perfectly fine now.Thanks all.<br /><br />Now i want tips on how to make the motor faster..