johnson 90hp j90tlcte bogging at WOT

swolgamott · Sep 10, 2013

Johnson 90hp DOES NOT HAVE VRO. I mix the fuel myself. I just had ignition system mostly redone. new spark plugs, new power packs, new starter, new wiring. carbs have been cleaned and float set properly.

The boat has been running solid at WOT. Tonight while riding it all of sudden just bogged down hard and there was no recovery. It did NOT stall. It is idling fine and fast idling fine. I can run the throttle up but it just sounds like it's working so hard for naught.

I have bypassed any filters and gone straight from fuel tank to engine. It still bogs down.

A couple things to note:
Positive:
It cranks right up
Was running great no problem
idles fine and can go mid throttle

Negative:
Bogs on WOT
When I came to boat tonight there was some obvious fuel had been slowly leaking from somewhere
When I lower the engine down into the water there is a rainbow

thanks for the ideas.

Daviet · Sep 10, 2013

Re: johnson 90hp j90tlcte bogging at WOT

Welcome to the forum.
You might want to start by checking the spark and compression. The spark needs to jump a 7/16" air gap and be bright blue.
Finally, you might want to check the high speed orifices to see if one is plugged or restricted.

swolgamott · Sep 13, 2013

Re: johnson 90hp j90tlcte bogging at WOT

thank you for the reply. I just had 2 new powerpacks put on, new cables and new plugs. Compression is 120 all the way around.

i update. it is still bogged at WOT, but when I engage the choke solenoid it revs stronger. Is this a telltale sign of high speed carb jets being the problem?

schematic · Sep 13, 2013

Re: johnson 90hp j90tlcte bogging at WOT

swolgamott said:
thank you for the reply. I just had 2 new powerpacks put on, new cables and new plugs.

Spark still needs to be checked. There are several other components in the ignition system that may fail including "new" powerpacks.

as Daviet states

swolgamott said:
when I engage the choke solenoid it revs stronger. Is this a telltale sign of high speed carb jets being the problem?

Certainly can be. Disassemble carbs and clean thoroughly. Don't run engine at WOT until issue resolved or engine damage may occur.

as Daviet states

swolgamott · Sep 13, 2013

Re: johnson 90hp j90tlcte bogging at WOT

Thanks for the reply. I will be checking spark and cleaning carbs today and will report back.

How much of a possibility in this issue is the fuel pump? I did a rebuild on it not too long ago and the boat has been running just fine since.

Daviet · Sep 13, 2013

Re: johnson 90hp j90tlcte bogging at WOT

You can over ride the fuel pump by constantly pumping the primer bulb, if the problem goes away by doing that, I would look at the fuel pump.

swolgamott · Sep 14, 2013

Re: johnson 90hp j90tlcte bogging at WOT

Was going up to the boat ramp from our dock to pull out to work on, and it felt like I was only firing on 3. I put in neutral and went to grab the latch to pull the hood and fiddle with cables. I got bit hard by some current! After killing motor I found that one cable had blown the boot off. I got back to dock and got a replacement. See what happens today.

V153 · Sep 14, 2013

Re: johnson 90hp j90tlcte bogging at WOT

The plug cable did not "blow the boot off". You snagged it on the latch from the cowl, happens all the time. Never liked that arrangement.

Your bogging problem is most likely caused by a chunk of crud in one'a the high speed jets.

What kinda condition is your fuel line in?

swolgamott · Sep 14, 2013

Re: johnson 90hp j90tlcte bogging at WOT

I'm sure your right. The setup is terrible. Although, one time (not this time) i heard a loud pop (the hood was off) and one of the plug wires was separated from the boot. I'm sure it was a result of being snagged enough though.

The fuel line is new. Carbs recently cleaned (multiple times!).

I'm almost sure it's only running on 3 cylinders. It has that tick. After I fixed the spark wire issue the performance improved dramatically from where it was before I knew of the issue with the plug. It was not restored completely though.

I'm going to change plug wires and plugs after I check spark and compression.

needing_help · Oct 23, 2013

needing help

needing help

I have replaced all ignition parts except stator witch seems to be in good condition. New coil packs , new ignition pack, good compression 120 , new plugs and wires , rebuilt carbs,all new fuel lines and getting spark but Boggs down just passed fast idle . I tried rec 90 fuel no difference. It's starting perfectly and isles great just no power offer fast idle..... Up for any suggestions.... Thanks

V153 · Oct 23, 2013

Re: needing help

Re: needing help

Make sure you haven't got the coil leads reversed top to bottom. Should be yellow wires. One with a blue stripe & the other green. Think "Sky blue, grass green."

emdsapmgr · Oct 24, 2013

Re: johnson 90hp j90tlcte bogging at WOT

If the engine runs better when choked, the engine is running lean. It's possible that the mid range carb jets have some debris in them. When you had the carbs apart, did you remove all the jets and visually inspect them to be sure they were all clear? (idles, mids and mains) Your description of your ignition components replaced does not mention the stator or the timer base. Have you checked them for output?

Ui'wai · Aug 24, 2015

I have a 1999 90hp Johnson PLEEB. engine runs great, the issue is when under load it boggs and will not exceed 1000rpm. Im guessing it is carb related but had all carbs rebuild a year ago. fuel is clean/clear and filter is new/clean. any suggestions on where to start to isolate the problem? could it be a stuck choke or bad fuel pump? thanks in advance for any help.

GA_Boater · Aug 25, 2015

Ui'wai said:
I have a 1999 90hp Johnson PLEEB. engine runs great, the issue is when under load it boggs and will not exceed 1000rpm. Im guessing it is carb related but had all carbs rebuild a year ago. fuel is clean/clear and filter is new/clean. any suggestions on where to start to isolate the problem? could it be a stuck choke or bad fuel pump? thanks in advance for any help.

This thread is 2 years old. Please read the Help Tip on top of the page and start your own thread.

Closed.

johnson 90hp j90tlcte bogging at WOT

Recruit

Fleet Admiral

Recruit

Lieutenant Junior Grade

Recruit

Fleet Admiral

Recruit

Lieutenant Commander

Recruit

Recruit

Lieutenant Commander

Supreme Mariner

Recruit

Honorary Moderator Emeritus