Johnson 150HP intake manifold plugged?

ShadowX

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Oct 10, 2010
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I have a 1993 Johnson 2-stroke 150HP outboard (J150EXETG) that I recently did a carb rebuild. When I looked at the intake manifold on the port side, I noticed there are two orange plugs on the left fuel ports on the top and middle cylinder. It did not look normal to me.

The port on bottom cylinder looks clear on the same location. It feels very solid like a rigid flat plate over the hole and not debris. I did notice the previous person who changed the carbs may have use some sort of gasket material from a tube that I had to clean out.

Has anyone seen this before? I was wondering if that may have been gasket material that dissolved in the fuel and plugged up the hole. Is it okay to remove the plug or would it cause damage to the intake manifold?

Any help from a mechanic who has rebuild Johnson outboard motors would be great.

intake manifold.jpg
 

willyok

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Hard to tell looks like it could be a screen filter. With the proper tool, you may be able to remove it. Or look at a parts breakdown.
 

ShadowX

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You may be right. Its may be a clogged screen. Its definitely blocking the flow of fuel. The orange stuff could be the remains of the gasket material. You can see pieces of the gasket material and it was orange in color also.

I ended up picking the screen off since there is no point in having a port completely blocked. The engine ran fine, but I haven't taken it to water and go WOT yet. I may run it a bit more with the water hose this weekend and verify that it does not have problems at the higher RPMs.
 

sickcat

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You may be right. Its may be a clogged screen. Its definitely blocking the flow of fuel. The orange stuff could be the remains of the gasket material. You can see pieces of the gasket material and it was orange in color also.

I ended up picking the screen off since there is no point in having a port completely blocked. The engine ran fine, but I haven't taken it to water and go WOT yet. I may run it a bit more with the water hose this weekend and verify that it does not have problems at the higher RPMs.
Running on the hose at a given RPM will require considerable less fuel flow than running at the same RPM under load. Certainly not a bad idea to run it on the muffs but running under load is the true test.
 

ShadowX

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Running on the hose at a given RPM will require considerable less fuel flow than running at the same RPM under load. Certainly not a bad idea to run it on the muffs but running under load is the true test.
I agree, but its always best to do a quick test on dry land instead of finding out after you launch. I will repeat the test on water, but if its has a problem with the muffs, its time for some elbow grease. I've seen guys stall out on the launch pads and in the water and its not pretty.