1998 Johnson 225 stalls when accelerating

Blakek25

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My 1998 Johnson 225 has been running poorly recently. It idles a little rough, but the bigger problem is that when I give it gas to accelerate it likes to die. This problem is the worst when I am fishing at a spot and the motor sits for a while. If I am on plane and slow down and idle around for a while and then take off again, it will take of normally. In order to take off when it is running poorly, I have to barely give it throttle until it reaches 1000 rpm, then I have to punch the throttle and it will usually take off. If I give it throttle slowly after it gets to 1000 rpm it will die. The only way I can get it to go is to give it full throttle quickly. While I was attempting to diagnose the issue today, I pumped the primer bulb to see if I could find any leaks anywhere. While doing this I noticed fuel coming out of the hole the arrow is pointing to in the picture. This is the middle carb on the starboard side. I assume this is not normal because none of the other ones were doing this. After I pumped the bulb, it would take a little while for the flow to start, then it would run out for a few minutes. I was thinking it might be a bad gasket but I am not familiar with the internal workings of these carburetors. I was wondering if these issues might be related, or what the problems might be.

Thanks for the help!
 

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ob

Admiral
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^^^^ This. That fuel leaking out is evidence of a sticky float or leaking needle valve in that carburetor. You'll also need to synchronize the linkage once you're finished going thru the carbs.
 

Blakek25

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I took two of the carbs apart tonight, including the one that had the gas coming out of it. They both looked really clean and all of the gaskets looked to be in good shape. The only issue I was able to find was a little wear on the float valve in the carburetor that was leaking. This may have been the reason for the leaking, but would it cause the acceleration issues? I am just hoping to avoid spending the money on carb kits to find that the problem still exists.

Also, I was checking some other possible issues and noticed that the spark plug gaps were not correct. One of them was too close and the other five were over. Could this cause an issue like this? They weren't terrible but they were obviously wrong when checking with the gauge.

Thanks
 

Faztbullet

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Clean the carbs and install new floats/gaskets/needles and then clean the calibration pocket on throttle bodies as this is 90% where idle/lean problems occur.
 

Blakek25

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I finally got my parts and was able to complete the rebuild. It seems to be running better but I am still messing with the idle screw adjustments. I think I am getting close but I ran out of daylight today.

However, while I was adjusting the carbs I noticed they had a white, milky looking fluid in them. as seen in the picture. It seemed to get better as i adjusted the carburetors richer. I was wondering if this is a sign of water in my gas, the carb adjustment being to lean, or another problem. I don't know if it would affect it, but the humidity was above 80% while I was running it.

Thanks
 

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ob

Admiral
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Yea ..that don't look good. I'd guess water in fuel. Got a fuel water separator aboard?
 

Blakek25

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Yes, but I have never replaced it. I will see if I can get a new filter.
 

Faztbullet

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That's normal as the venturi speeds up air flow causing temp in carb to drop and the humidity in the air will condense and puddle there...it is a mix of water and fuel/oil vapors and will not cause issues. As for the mixture screws you cannot adjust these on a hose!!! Boat must be in water,trimmed level, in gear, untethered,then adjusted...starting point is about 5-1/2 out from light seat.
 

Blakek25

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After a couple trips to the lake with no success, continually adjusting the carbs richer, it still lean sneezes and idles rough. The last time I had it out, I let it idle on the trailer for a minute or two so that I could inspect the spark plugs when I got home. Upon inspection, the middle spark plug on the starboard side was white. From what I understand, this means it is the one that is lean. I decided to take apart the carb for that cylinder (middle carb on port side), thinking I might have contaminated it when I rebuilt it, and something was plugging up a hole. However, I found nothing. Is there something else that could be causing that cylinder to run lean at idle other than the carb, or is there something that I might be missing?

The motor runs the same as before at WOT


Also, I checked the contents of the fuel water separator, and I found no water.

Thanks
 

daselbee

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Throttle bodies...as Fazt said above. Search function. You will be covered up with hits.
 

Blakek25

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daselbee, are you referring to post number 6? I should have specified, but I also took apart the calibration pocket on the throttle body and it was clean. I also adjusted the lync and sync when I rebuilt the carbs originally, but i don't think this was the problem or it would have been both of the top two cylinders

Thanks
 

daselbee

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Yes post #6. Pockets can look clean, but unless you inspect with a flashlight the 5 tiny holes deep down in there, you could miss the fact that the holes are clogged.

You must eyeball theose holes and ensure they are clean and open. The smallest is 0.010. Very easy to clog with gasoline resins and gum.

Did you put eyes on those holes and ensure they were open and clear? Shine a light thru, run a welding torch tip cleaner thru each hole to make sure they are open?
 

Blakek25

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When I took the throttle body back apart, the holes were all clear, and I ran a small wire through each just to make sure. I finally decided to swap the carb and throttle body with the one from the other side. I also swapped spark plugs. However, the problem still persists and the spark plug on the same cylinder is still white after it is ran at idle for a little bit. I attached a picture of the white spark plug and a normal plug from another cylinder. The spark plug is not a milky white, the plug itself is white. Are there any other possibilities, or am I missing something?

Thanks
 

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Blakek25

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I put a timing light on it and I did not notice that it was double firing. One thing I have not mentioned yet was that to get on plane when it was not running good, I would have to hit the primer.

Also, when I took it out last time, it would begin to jump on plane as normal, but right before it planed out, it acted like it was dropping a cylinder. I could feel it fire every now and then, but it would not fire consistently. This seems like more of an electrical issue, but I haven?t had time to trouble shoot anything yet and thought someone might be able to point me in the right direction. Not sure if this is another issue, or the same issue causing more problems?

Thanks
 

racerone

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Hitting the primer puts fuel directly into the motor.-----This fuel bypasses the carburetors.----That strongly suggests a carburetor problem.
 
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