96 Johnson Oceanrunner 150 misfire and pour idle

[Nkillian19]

Recently went to the islands. Boat ran great. After hanging out for 2 hours we left. About half way back the motor fell on its face and ever since It keeps doing this. Itll run fine, get out the marina and give it to abour 3k crusing speed and run great them i give it a little more and it falls on its face and wont run right the rest of time. I put new fuel filter, water separator, primer bulb. New plugs about 1 month ago etc. Any help would help.
video of it running.
https://youtu.be/-BRPlka-L6M

 

[dingbat]

Checked fuel pressure and compression lately?

Still running the OE (24 yro) fuel pump?

 

[oldboat1]

Post a model number.

Check the water separating filter to see if water is present. If so, will need to drain the tank.

 

[Nkillian19]

Checked fuel pressure and compression lately?

Still running the OE (24 yro) fuel pump?

I Havent. Didnt know it had one tbh. Thought it was suction driven. Primer pump doesnt really get hard but when it does it doesnt stay hard very long. It is new so figured the carb bowls being warped could be an issue.

 

[Nkillian19]

Picture of fuel that was in water seperator

 

[dingbat]

I Havent. Didnt know it had one tbh. Thought it was suction driven. Primer pump doesnt really get hard but when it does it doesnt stay hard very long. It is new so figured the carb bowls being warped could be an issue.

The end result of a warped fuel bowl doesn't happen all of a sudden. Lots of thing that could go wrong before jumping to that conclusion

1. Have you checked the compression of the motor to verify that all cylinders are within 10%?

2. The fuel pump utilizes a rubber diaphragm to pressurize the fuel. You need to measure the fuel pressure to see if the pump is pressurizing the fuel up to specification. Pretty good chance a 24 yro rubber diaphragm is compromised

3. The primer bulb (pump) is only used to prime the fuel pump. It's does nothing once the engine has started.


https://forums.iboats.com/forum/engi...-pump-question

 

[Nkillian19]

I will check fuel pressure. Do you know what it should be? Also this is what all the carb bowls look like

 

[dingbat]

Also this is what all the carb bowls look like

Is there a significant amount of fuel leaking from the bottom of the bowls?

If not, that's not your problem.

 

[Nkillian19]

Is there a significant amount of fuel leaking from the bottom of the bowls?

If not, that's not your problem.

I always see a decent amount of fuel pooling on the bottom of casing. Where the power head sits in. Sometimes goes into the water and you can see it. I built up a good amount of gaslet maker around all 6 carb bowls. Ik before this issue it woild idle horrible and figured it was the carbs. Knocking out multiple issues at the same time so. Will check fuel pressure soon and get the numbers back to you.

 

[dingbat]

Ik before this issue it woild idle horrible and figured it was the carbs.

It would be nice to have this information in your original post. You made it sound like the problem developed on your return trip.

Hope you didn't use anything other than the OE rubber gaskets on the carb bowls. Don't know what "gasket maker" you used, but you may have just identified your problem.

 

[iggyw1]

I will check fuel pressure. Do you know what it should be? Also this is what all the carb bowls look like

Just placing a straight edge on the picture you posted here, I can see a definite warp in the bowl/ That would cause your motor to suck air in if gas is coming out, & you said it is accumulating in the casing beneath the power head. I would say this is your problem.