Is this the idle jet? Or?

Hey folks- is this the idle jet or maybe the idle screw that is adjusted with specific turns? 1999 Johnson 175hp..they are on the exterior of all 6 carbs..can I spray carb cleaner into them or do they need to be removed? Thanks in advance..

Bowl Vent/Calibrated Air Bleed

What is your motor doing / not doing ?

Thanks for the reply’s- I have two problems going on (I think) with a 1999 Johnson 175PLEES with only around 400hrs…kept in incredible shape by previous owner I’ve now had it 3 years…rebuilt carbs maybe 18 months ago..this is gonna be long winded apologies in advance

Just recently (April 12) replaced all 6 plastic carb bowls as they were warped- I forgot to transfer the high speed jets over to the new bowls and on my first run could not get on plane- fixed that issue and thought I was good to go but I have now bogged down twice since-(April 15 and May 3 but with multiple fishing trips in between with no issues) getting on plane then losing rpm’s almost like it could be fuel starved or junk in fuel but also a similar sound to when I had forgotten to transfer over the high speed jets…but on both occasions I was able to get her going and run back in to the no wake zone but it was a “lungy/sometimes boggy” ride in..if I really opened the throttle up to 4500 it would hold plane but sometimes drop down to 3700 then back up to 4500…kinda herky jerky ride back in then a slow put back to the dock in low rpm’s seemingly ok

That issue has only happened twice and seemingly random as I had multiple fishing days/trips in between with zero issues. The other problem- when I go to my dock and start the boat cold in the morning it fires right up, goes through its initial fast idle then settles in and idles perfectly- and let’s say I go out to the ocean and troll for bonito or Spanish for several hours never turning the engine off the engine runs perfectly…but if I turn the engine off and say fish with the trolling motor for 30-45 min, when I try to start the engine up again it’s giving me the sneezes and losing rpm’s and won’t idle…sometimes I can advance the throttle and keep it started and get in in gear and if I run and get on plane at 3500 rpm’s she settles back and will idle fine upon slowing down- but again if I turn it off for 30-45 min she doesn’t want to restart and gets the sneezes and in the last few days even if I advance the throttle as if it was flooded for a restart she still konks out to the point I had to use the trolling motor to get back to the dock.
However, for the last 3 days after some experimenting and getting to the point where she will not restart at the dock at all- but when I trim the engine up and give up and come back the next morning she fires right up, idles perfect, gets on plane -but again once I turn it off for 30-45 min we are back to sneezing out.

So how might the engine be fixing itself overnight?? I pulled the plugs yesterday to take a look- they all looked relatively the same here is a pic- sprayed a bit of brake cleaner on each one and a light cleaning but once reinstalled the engine showed no improvement.

Since I’ve owned it there has always been a bit of fuel/oil mix in the carb throats after use and ending up in the airbox and often some in the lower cowling that drips out if I trim it up in the driveway then trim it down I’ll find a bit of gas/oil on the prop the next day like 7 or drops worth (including a pic of carb throats)

So I’ve ordered new carb kits and gonna do the carbs again (that’s where my question came about the jet I pictured wasn’t sure if I should clean that too)vro still working on this one- just perplexed how the engine “fixes itself overnight”…wet plugs? Flooding issue? Too rich too lean ?

Any advice greatly appreciated sorry again so much typing….

I would look at the float / float valve in vapor separator.----Replace diaphragm in the wee vapor extraction pump.----Replace gasket on the tank cover.------Check internals of the VRO pump.------Check fuel lines , anti syphon valve from tank to motor.----Perhaps test run with a portable tank handy when motor acts up.

Update….so went to the dock this am, another repeat of the last 3 days- after struggling to get it to start yesterday at 3pm she fired right up this morning, idled great- ran it 5 miles or so through various rpms she ran like a top- idled fine when I paused

Took it to the boat ramp to bring to the house to start the trouble shooting, literally in the time it took to back the trailer down and restart the boat to get it on trailer she wanted to sneeze out and die

Brought it home out the muffs on rinsed her, she actually did a little better with the muffs on idling around 1300 which was kind of interesting but she eventually sneezed off…

Tried a visual pressure test getting the fuel bulb tight and after hearing her fill with gas- then hear what sounded like air being released somewhere in the vicinity of the vapor separator but I can’t be certain? A sort of whooshing sound (no visible gas leaking from vapor sep gasket)
After 6-8 heavy prime on the bulb (once it got hard which did take 12-15 pumps) finally saw fuel leaking out of the throat of the bottom carb if facing the engine on the bow…..so maybe that’s the issue unless I ruptured something new due to the prime test? I know that bulb can create a lot of pressure correct?

Any thoughts greatly appreciated

Update #2…on 1999 Johnson 175 BJPLEES ...pulled all the carbs off yesterday, no major “aha!” moment with any of the carbs but some of the fuel bowl gaskets had small tears in them from me tightening the float bowl screws too tight- so I replaced all those gaskets along with a few float bowls…put it all back together and she fired up nicely on the muffs out in the street. Took the boat to the ramp she fired up just fine got into a nice idle- ran a few miles up the waterway and back to the boat ramp- she idled fine when I paused her here and there and ran fine all the way up to 4500 rpm’s…got back to the boat ramp backed the trailer down- waited 25 minutes and then restarted the engine and she started sneezing /coughing again in indie losing rpm’s and then turning off. Got her back on the trailer- pulled back to the street in front of the house put her on the muffs and she actually held idle better the first attempt - but then tried again an hour later and the attached video is the result- when she sneezes/coughs exhaust comes out and eventually turns off

As a process of elimination 6 new champion spark plugs are about to go in to see if that makes a difference.

Take pics of the Plugs, I would clean them instead of replacing them, then run it again to see if that was the issue

jimmbo said:

Take pics of the Plugs, I would clean them instead of replacing them, then run it again to see if that was the

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jimmbo said:

Take pics of the Plugs, I would clean them instead of replacing them, then run it again to see if that was the issue

Click to expand...

Pics of the plugs just above in this thread- replaced them in

jimmbo said:

Take pics of the Plugs, I would clean them instead of replacing them, then run it again to see if that was the issue

Click to expand...

Update #3 cleaned carbs, replaced old plugs with new plugs- engine still fires up just fine in the morning (with no fuel bulb priming just push in key prime) and will idle like a top and run perfect for hours until I turn the engine off and let it stay off for at least 20 minutes, then upon restart she doesn’t want to idle well and sneezes//coughs while losing rpm’s and then cutting off…

I now can pump the fuel bulb hard by hand and as the engine is trying to cut off in idle and it seems to stay running without the coughing /sneezing and then continues to idle well after I’ve stopped hand priming the fuel bulb….so maybe it’s just been starved of fuel?? but I had tried that a few days ago and that didn’t work but it is now…so now I’m thinking it’s hopefully just the fuel bulb itself. So bought a new bulb and new fuel line so replacing that in the am….if that doesn’t work I’m think something in the vro fuel pump???? Fuel vent line is clean-clear of debris …..whew….serenity now serenity now.

Torque on float bowl screws is 10 / 12 INCH LBS.----Which is not very much.

You just said you were gonna take them out and replace them again.

I don't care about the Old Pics, I would like to see what the Plugs that were just run, look like

That issue where the motor sneezes after running for a while and then sitting seems to be common on those engines. It is on my '98 Johnny 150HPV6. A work around is to start the sneezing engine and keep her idling high enough in neutral to keep running for a few minutes. After that she should run just fine.
You might change the thermostats, if they are older, as I think it is a heat soak issue.

Chris1956 said:

That issue where the motor sneezes after running for a while and then sitting seems to be common on those engines. It is on my '98 Johnny 150HPV6. A work around is to start the sneezing engine and keep her idling high enough in neutral to keep running for a few minutes. After that she should run just fine.
You might change the thermostats, if they are older, as I think it is a heat soak issue.

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Thanks Chris- yes since I’ve owned it (3years) it has often done this but it is currently doing worse than in the past and yes often I have just bumped the throttle up to keep it from coughing out in idle and then once I get it in gear and run on plane to new fishing location she is idling good again…good tip on the thermostats I’ll try that today as well along with a new fuel bulb.

The " lean sneeze " is much mis-understood.----Adjust low speed mixture screws to get rid of it.----Most motors will sneeze a few times when cold.----Should disappear after 15/ 20 seconds after cold start.

racerone said:

The " lean sneeze " is much mis-understood.----Adjust low speed mixture screws to get rid of it.----Most motors will sneeze a few times when cold.----Should disappear after 15/ 20 seconds after cold start.

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Yes mine does not lean sneeze on a cold start ( first start of the day) , but wants to lean sneeze after my first stop at a fishing location after I’ve ran say a couple miles then turned off the engine to fish…then when I restart and want to head to another location I’m getting the “lean sneeze” in idle and she’s wanting to konk out and then sometimes (lately) not want to restart at all. But the initial cold start each morning she idles absolutely perfectly.

Update #4….spent the afternoon on the water- some improvements in the idle after stopping, not perfect but less sneezing after fuel bulb change, carb clean and 6 new plugs. However! Some new problems have surfaced, she now sounds a little “rough” - and across the rpm range up to 4500 there is a slight reduction in rpm’s here or there, like a dip between 100-200 rpm’s here and there…so that’s new, and around 3300 on up I’ve got a new “rattle like “ sound that could be best described as a loose nut is gettting all tossed around in the engine which is certainly a bit alarming.
At the dock and just pulled the new plugs out after two hours of use and am including pictures of them- the middle right one looked the “worst”. Gonna put the old plugs in and take for a spin to see if the same rattle/slight drop in rpm’s while cruising occurs. Thanks again for all the input.

Has VRO oil consumption been tested / checked?----Lower unit gear oil checked / changed?----The gearcases on some of these are not robust in my opinion.----And have compression values been posted ?