1999 Johnson 225 Ocean Pro

Bteach

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Aug 31, 2018
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Model #J225PXEEC
I recently rebuilt the 6 carbs on a 99 Johnson I purchased. Some of the gaskets were very tough to fit and keep on while doing this and I put the carbs with gaskets that stayed on better on the bottom and worked my way up rather than putting them on exactly how I got them off. I tested my engine the other day. To start with I had a gas leak on my tank and it wouldn't stay primed and idling, which I fixed. Afterwards it would stay primed but still seemed to not get enough gas as I got on the throttle. I had a helper with me who kept pumping the bulb while we tried to plane it out. At full throttle I ran at 4k rpms, roughly 34mph. Previous owner said the motor would push the boat at around 60mph. Im trouble shooting at this point. I assumed all of the carbs were the same on the motor when I put them back on but im questioning whether or not the jets are different in the carbs. Have I made a mistake by putting them back on the way I did? The motor sat for 3 years so my first thought was to go through the fuel pump as well. Any insight would be greatly appreciated!
 

Chris1956

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Mar 25, 2004
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On the part's list the carb jets look to be the same for all carbs. However, a lot of the carboration occurs in the Throttle Bodies. Did you clean them?
 

Bteach

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I didnt take it off and clean it but I did spray the surface and holes that were facing outward. I've rebuilt smaller motor carbs in the past and this particular motor has one throttle body that extends the length and width of all 6 carbs, like a plate. I spoke to a Johnson mechanic when I bought the motor and boat and he said not to take it off when I went through the carbs so I didnt.
 

Chris1956

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Mar 25, 2004
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On my '98 Johnny 150, the throttle bodies (2) have side plates that contain the idle needles. Obviously these need to be cleaned. The TBs also have orafices which get dirty.
 

dingbat

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Nov 20, 2001
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Don’t know about your 99, but my 97 uses different jets in some carbs.

Don’t think that would cause the problem at hand, but you need to sort out the jets for long term survival

Make sure you clean the manifold/throttle bodies. They do get gummed up sitting
 

Bteach

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Aug 31, 2018
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I appreciate it guys. Im gonna take the throttle bodies off today and go through them, replace gaskets and give it a go. I also went through the fuel pump which was suprisingly clean I thought....I will let you know how it works out. Thanks again for the advice.
 

Bteach

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Aug 31, 2018
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Compression was the first thing I tested and was good when I purchased it. I tested it on the guys yard on a small gas tank with some good gasoline. I think I’ve found my issue but I’m waiting on parts. I took the fuel pump and carbs off to clean the fuel pump and go back and make sure no trash made it into the carbs. The carb rebuild kits came with new spring clips for the carb and the pins seemed very loose so I tightened them slightly. I took the carbs apart and was missing one in the carb so I think I came off during my rebuild. On another note. I have no idea where this line goes. It’s up under the throttle body coming off the crankcase and I can’t find it in my manual I purchased. Any input? It’s never it’s never been attached to anything or recently cut by the looks of it and I can’t upload a photo for some reason ...
 

Bteach

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So i took my boat out this morning and ran it a little. The boat ran good about 2500 rpms but when i tried to throttle up it bogged down just as it had so there is some improvement from the cleaning the throttle body. When I ordered a spring clip i had to get another rebuild kit for a carb so I ordered the OMC instead of Sierra and I noticed the gaskets were thicker on the Sierra brand. When you put the Sierra on it sort of half blocks the lowest gas port on the carb that goes down into the bowl. Its not flush beside it so it doesnt restrict it in a sense but the gasket is thicker. I also put a dye in my gas tank and ran it, noticed I had a leak that I hadnt previously seen so that will be the next thing I correct before trying it out again.
 
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