1999 Johnson 150 Hp No Power @ Wot

[Bass Ackwards]

I've got a 99 Johnson that's really starting to drive me nuts! It has sat for the past 2 years due to work & high gas prices, but I'm trying to get her back in the water. I've already cleaned out all the old gas, installed new feul filter, rebuilt the 6 carbs, replaced the lower unit oil, topped off the pwr tilt fluid, and generally lubed up everything. Today, I finally got her in the water, started her up, and took her out. Everything was good until I opened up the throttle, and she just died out. Many restarts with the same result. So I limped back to the dock, and barely had enough power to get'r back on the trailer.
Any advice would be much appreciated, the manual is a bit vague, and lists many posibilities. So if you've had this happen to you, I'd like to hear what your problem was, so I have a good starting point!
Thanks!!

 

[tashasdaddy]

Re: 1999 Johnson 150 Hp No Power @ Wot

did you remove and clean all the jets? i just did a 115hp carb today, when i opened it, i almost closed it back up, it was so clean, but the high speed jets were gummed up, you could see light thru them. but it was only 1/4 of the opening clear.

also do a linc n sinc, this lets the spark advance and carbs work together at the proper time.

you also could have a weak fuel pump, not providing enough fuel. vent on fuel tank clogged. air leak in fuel line.

also have you check your compression and spark on all 6 cylinders?

 

[Bass Ackwards]

Re: 1999 Johnson 150 Hp No Power @ Wot

Sorry it took so long to get back to you.

did you remove and clean all the jets? There were no "jets" to speak of to remove. I followed the instructions of the SELOC manual in regards to rebuilding the 6 carbs. I removed and replaced all there was to R&R. I also cleaned the entire unit with carb cleaner. It ran much better after the rebuild while sitting in the driveway.

also do a linc n sinc, this lets the spark advance and carbs work together at the proper time. I do not know what this is, or how to perform it, but I'd love to know how. I visually checked the carbs opening and closing in relation to throttle movement, and they all seemed to be working together. I did not check the timing, as I do not have a timing light.

you also could have a weak fuel pump, not providing enough fuel. vent on fuel tank clogged. air leak in fuel line. My first suspect if the fuel line with the squeeze bulb. I haven't replaced it yet, but I did purchase a new one and will be installing it tomorrow, after work. I fired up the motor today, in the driveway, and it seemed to be running a bit rough. After it warmed up, I went to full throttle, and tho it didn't have any resistance against the prop, the motor seemed to surge with almost a constant up and down of the rpm's. Unfortunately, I was too busy trying to see thr fuel flow thru the newly installed in-line clear fuel filter added to the section of hose that runs from the back of the boat to the motor, and I didn't notice the up and down surging of the rpm's, but a quick glance saw it to be between 6 and 7,000. I believe the vent is clear, I see no obstructions as it sits just aft of the fill port. No too sure about the fuel pump, gonna have to resaearch how to check it.


also have you check your compression and spark on all 6 cylinders? No, I haven't the tool for that, but am willing to pick one up, they can't be too expensive.

I see your a fellow Jax person, I'm in Orange Park, and I thank you for your help. Any other advise would surely be welcomed. I've found that the only place I can get to work on my motor is Beck's but I'm trying to avoid that since they are so busy, it'll probably be there for awhile!

Thanks again!

 

[Chris1956]

Re: 1999 Johnson 150 Hp No Power @ Wot

Bass, You need to get an inductive timing light and a compression gauge. Remove the spark plugs, put the compression guage into each spark plug hole in turn, jumper the starter solenoid and note the max reading. All cylinders should be 100+ PSI and within 10% of each other or so.

Next reinstall the plugs and put the timing light on each plug wire. Crank the motor with the key and see if the timing light.

If compression is good and you have spark, then buy a OMC Service Manual and perform the Link and Synch to set the spark timing to the throttle setting.

 

[Bass Ackwards]

Re: 1999 Johnson 150 Hp No Power @ Wot

Thanks!

I'll go and get an inductive timing light and compression guage, and do the checks.

Next reinstall the plugs and put the timing light on each plug wire. Crank the motor with the key and see if the timing light. See if the timing light what?

buy a OMC Service Manual and perform the Link and Synch to set the spark timing to the throttle setting.
I have a SELOC manual for the motor, but I didn't see link & sinc in there...how do I do that?

I'll let you know what happens, as it does!! Thanks again!

 

[Chris1956]

Re: 1999 Johnson 150 Hp No Power @ Wot

Bass, The timing light will tell you if you have spark to the plug which is ti attached to. If you test all the plug wires, and the light comes on, you have spark to all plugs, which is correct.

Even the Seloc manual will have a link and sync. It may be under the tune up section. It will tell you how to set idle spark timing, max spark timing and how to synchronize the carbs to the spark advance.

Basically the carbs on my '98 150HPV6 should start to open when the timing is 6*ATDC. Max spark avance is 20*BTDC

 

[ondarvr]

Re: 1999 Johnson 150 Hp No Power @ Wot

did you remove and clean all the jets? There were no "jets" to speak of to remove. I followed the instructions of the SELOC manual in regards to rebuilding the 6 carbs. I removed and replaced all there was to R&R. I also cleaned the entire unit with carb cleaner. It ran much better after the rebuild while sitting in the driveway.


There are jets in each carb and it's very important to clean them very well, plus the area around them. Get the manual and it will show you exactly where they're located.

 

[Bass Ackwards]

Re: 1999 Johnson 150 Hp No Power @ Wot

Bass, The timing light will tell you if you have spark to the plug which is ti attached to. If you test all the plug wires, and the light comes on, you have spark to all plugs, which is correct.

Even the Seloc manual will have a link and sync. It may be under the tune up section. It will tell you how to set idle spark timing, max spark timing and how to synchronize the carbs to the spark advance.

Basically the carbs on my '98 150HPV6 should start to open when the timing is 6*ATDC. Max spark avance is 20*BTDC I bought an inductive timing light, compression tester and a spark plug tester, though I haven't had the chance to perform the tests as of yet. However, reading my SELOC manual, in regards to idle timing, the manual says I need an Evinrude/Johnson Ignition Analyzer, and that setting the timing without one usually does not work, so I am a bit hesitant. And you are correct on the settings, the manual states idle is 6*ATDC and max is 20*BTDC, but again, spark advance requires the Ignition Analyzer. Unless you have another way...

In regards to the linc n sync, I found no direct reference to that procedure, tho I did find ref's to setting the timing pointer, throttle plate synchronization, idle timing, max spark advance, & spark/throttle pickup point, but again, all requiring the Ignition Analyzer.

I am still able to do the compression test, and I will test the plugs. Visual inspection of the plugs today showed all but 1 with a bit of oily residue on them, and the one was dry and slightly browned. I'm not sure which cyl it was, can't seem to find a simple plug designation in the damn book, but if you are behind the motor, looking at the 6 plug wires, the upper right plug was the dry one.

So, that's where I stand to this point, I'm hoping to due the plug test/compression tests tomorrow, when the neighbors are away, so I don't drive them nuts. I'm also considering removing the carbs again, to verify all the "jets" are clean, and to set all the floats to the same height, originally I adjsted them to within book tolerances, but I think I'll set them all to the gasket height, so I know they are all the same.

Thanks for all the help/suggestions!

Bass

 

[Bass Ackwards]

Re: 1999 Johnson 150 Hp No Power @ Wot

OK, performed the compression test on all 6 cyl today, and I did it cold, then again after I warmed the engine up. All 6 were above 100 psi with the lowest reading at 105 and highest at 110 (eng cold), after warmed up, lowest was 105 and highest was 115. So far so good. I also tested the spark plugs with a spark plug tester, and all are producing a steady spark.

This weekend, I am planning on removing the carbs (again), for a quick re-check of the jets and resetting all the floats to the same position.

What would be a good method of checking for a weak fuel pump? Since I have installed the clear in-line fuel filter, I can see how the fuel drains down as the motor runs, and slowly refills. Is this normal, or should I be checking the pump? Also, how do I do the linc-n-sinc? Can I do this without the Analyzer the book says I need?

Thanks!

Bass

 

[reeldutch]

Re: 1999 Johnson 150 Hp No Power @ Wot

you will have to take the throttle body of and clean the passages in there to.
could be clogged in there also.

 

[ondarvr]

Re: 1999 Johnson 150 Hp No Power @ Wot

If it died right as you were starting to accelerate, then it most likely is not the fuel pump, there would gas in the float bowls allowing it to run for a short time at high speed until they were dry. Clogged jets would have an immediate effect and not allow it to get on plane, or at least have less power than normal. Just pump the bulb while running and you'll know if its the fuel pump.

Plugged jets are the first, easiest, most common cause and least costly thing to check.