2000 Johnson 175 bogging down

[delphimark]

Hopefully a simple question:
I had work done on my 2000 model Johnson 175 early last summer. At the time, I was having a rough idle, and significant "lean sneeze". Turns out, my coils were cracked! Replaced them. Ran fine. While at the shop, I had a water separator added to my gas line. Boat ran great for a while, but now, is bogging down when I throttle. Idle is perfect. Initially, this bog down would only happen for the first few minutes after launch, then clears up and runs flawlessly. Yesterday, it idled great, started out, and it started bogging. It got on plane, but it continued to waver between running great, and bogging down.
It really feels like water in my gas. Is it possible that my separator is full of water, and being forced back into my fuel line? How often to I need to empty/clean out this separator?
The problem is getting worse... Any thoughts?

 

[reiddo1]

Re: 2000 Johnson 175 bogging down

Have you checked your water separator connections for possible air ingress? If the fuel line is clear at any point between the separator and the engine, you would certainly see bubbles. That would be a strong indicator of slack connections.

 

[delphimark]

Re: 2000 Johnson 175 bogging down

I have not checked the connection. I will do that now.
Should the primer bubble stay hard all the time? I notice that mine gets soft after a couple of hours. Would that be an indicator that there is air getting into the system?

 

[delphimark]

Re: 2000 Johnson 175 bogging down

Sorry... meant primer "bulb". Was looking at your word "bubble" when I typed that...

 

[delphimark]

Re: 2000 Johnson 175 bogging down

All connections seem to be tight. Also, I see no leakage around any of the fittings or the lines.
All of my fuel lines are black, therefore I can't see any bubbles.
I've never removed the canister of my water separator. I just tried, and I can't even START to turn it! Is it possible that it needs changing, or are you relatively sure it's more of an air problem?

 

[reiddo1]

Re: 2000 Johnson 175 bogging down

All connections seem to be tight. Also, I see no leakage around any of the fittings or the lines.
All of my fuel lines are black, therefore I can't see any bubbles.
I've never removed the canister of my water separator. I just tried, and I can't even START to turn it! Is it possible that it needs changing, or are you relatively sure it's more of an air problem?

At this point, I am not sure of anything. Is it possible to connect a small tank of fuel to the engine and bypass yourresent fuel system. If the engine goes to full throttle under load then you know your problem is your original fuel supply. If not then you know that your fuel quality and separator are not suspect. I cannot advise you on your separator since I do not use one but I would think that if it has water in it in such a short time, then using fresh gas from a small tank would help to eliminate that as a possibility. How Lon have you owned and operated this engine?

 

[reiddo1]

Re: 2000 Johnson 175 bogging down

I have not checked the connection. I will do that now.
Should the primer bubble stay hard all the time? I notice that mine gets soft after a couple of hours. Would that be an indicator that there is air getting into the system?

My primer bulb goes soft as well but does maintain its original shape.

 

[delphimark]

Re: 2000 Johnson 175 bogging down

How Lon have you owned and operated this engine?

I've been running this engine since 2008. I started having this problem at the beginning of this last fall. It felt like bad fuel, but after about 10 minutes of running, it would smooth out, and run fine the rest of the day. I've burnt a log of fuel through this thing over the past 6 months, but it did sit for a couple of months in December and Jan. But on my last trip, it never cleared up. It would still run 65mph, but it would bog for a second or two, then run perfectly. Then, it would bog, then it would run smooth.
Again, the idle is perfect. I would have thought that I would have run out the majority of the fuel, and what was effected by condensation, would have been caught in the separator.

 

[reiddo1]

Re: 2000 Johnson 175 bogging down

I've been running this engine since 2008. I started having this problem at the beginning of this last fall. It felt like bad fuel, but after about 10 minutes of running, it would smooth out, and run fine the rest of the day. I've burnt a log of fuel through this thing over the past 6 months, but it did sit for a couple of months in December and Jan. But on my last trip, it never cleared up. It would still run 65mph, but it would bog for a second or two, then run perfectly. Then, it would bog, then it would run smooth.
Again, the idle is perfect. I would have thought that I would have run out the majority of the fuel, and what was effected by condensation, would have been caught in the separator.

From what you have just written, I would think you have an ignition issue and because the symptoms last merely for a second or seconds at a time, it is unlikely that reading your spark plugs will give any clues. It might be wise to check all ignition grounds for tightness and cleanliness. Good luck...........Don

 

[delphimark]

Re: 2000 Johnson 175 bogging down

Okay... I fished today. First time I've run the boat since the "bog down" issue.
Prior to launch, as I was attempting to pump up the bulb, it never really wanted to get firm. I could hear fuel going through it, but it never did seem to firm up the way it usually does.
Here's the funny part: The boat ran like a sewing machine! No bogging down. No missing. It started right up, and ran perfectly!
And, let me tell you... I ran the DOG out of that thing! It was really responsive, accelerated well, jumped on pad... everything you could ask for in a boat!
Now I'm wondering if it may have been an issue with bad fuel.

 

[bob johnson]

Re: 2000 Johnson 175 bogging down

do you smell fuel at all?? on my motor which is a similar design.. the primer bulb in the gas line would not stay hard and id have to prime it several times before it finally would just run on its own...i went to finally replace the fuel pump and found that the big hose that goes to the valve threaded into the lower have f the crank case was split almost in half..and so there was NO vacumn, and it was leaking gas.

i replaced the whole pump with another and installed a new hose... the motor ran great and the gas smell went away and the gasline primer bulb stays hard now

bob

 

[delphimark]

Re: 2000 Johnson 175 bogging down

Did your motor run at all, with the hose split almost in half?
Usually, when I pump the bulb for a bit, it get's hard. But, after I run the motor for a while, it softens back up. But, I really don't have any cranking issues... even after it's softened.
I may experience the problem again tomorrow. I plan on fishing again. But, as I mentioned, it ran perfectly today.
I will check the hose where it connects to the fuel pump, just to ensure that there isn't a problem there.

Thanks!

 

[bob johnson]

Re: 2000 Johnson 175 bogging down

yes, once I ran about a mile and had to stop and repump the bulb 4- 5 different times to get out of the harbor at 5 mph....then the motor seemed to run fine


bob