96 Ocean Pro 200 won't idle after carb rebuild

[Norsemen9]

Looking for some experienced advice, before I go changing anything. I just rebuilt all (6) carbs on my Ocean Pro 200 and she runs great above 1000 RPM. Problem is she won't stay running at idle or below 900 RPM.

I'm going to adjust the Idling screws from the 5-turn starting point, but am trying to understand whether the engine is running Lean or Rich at that idle speed. The manual mentions "sneeze" through carb as lean, and running rough and unstable as rich....well I've got both conditions. So my first question is how to diagnose which condition?...and second question - do I make the same adjustment to each of the 6 carbs, when I make an adjustment?

Experienced advice greatly appreciated!

 

[boobie]

Did you clean the passages in the throttle bodies also ??

 

[Norsemen9]

No, I wanted to avoid resetting the throttle linkage so I removed just the carbs. I did clean the throttle body passages on the starboard side, but didn't on the port due to interference accessing the screws by the starboard throttle body.

My reasoning, other than the fact I wanted to be on the lake, was lack of contamination in the ones I did clean. That logic sounds kinda silly now. Would that be the first thing to check?

 

[racerone]

Have to ask---Was it idling well before work started ?----Any other trouble shooting done ?----How long have you owned it ?

 

[dingbat]

I had the exact same situation last spring. Cleaning the throttle bodies improved but didn't solve the problem.

Sprayed carb cleaner in the idle jet while trouble shooting. Spray came out a hair line crack at carb mounting flange on 4 out of 6 carbs.

Bought a pair of throttle bodies with carbs off eBay. The motor has never run better since

 

[Norsemen9]

Thanks for the advice!.....have owned the boat & motor for 12-years. This is actually my second carb rebuild, the first was 6-years ago. First time through, I did everything by the book. Thinking I should pull the port side Throttle body and clean the contamination pocket and idle screw area.

She was stalling at throttle up around 1500 RPM, before the carb rebuild. She runs like a champ now, but just wont idle below 900 RPM.

 

[daselbee]

Remember the small brass tube that extends down into the carb bowl? That is the source of ALL the idle mixture fuel. That tube must be clear, and the complete passage thru to the tiny holes in the side of the throttle bore, (deep down in the calibration pocket)...all that has to be clear.

 

[daselbee]

The two idle air bleeds in the front of the carbs....did you be sure to replace them in the correct locations?

 

[Norsemen9]

Sorry about the delayed response,....had other things going on and couldn't get back to the boat.

Yes, I went ahead and removed the Throttle Body's and cleaned the passages under the side plates, and I did clean the thin brass tubes really well with carb cleaner followed by isopropal alcohol. I then performed the Link & Sync per the manual. It's slightly better, but after coming down slow from WOT she dies at 700 RPM after about 12-seconds.

Not sure if it's relevant, but she doesn't start up from a cold start as well as she did before. Used to, I could turn and hold the key activating the choke and she would fire right up after a couple revolutions. Now it takes a process of that plus moving throttle a few degrees open, and about 5-minutes on the boat ramp.

Any suggestions are welcomed, as I'm not giving up!

 

[Faztbullet]

Did you use OEM kits????

 

[dingbat]

Not sure if it's relevant, but she doesn't start up from a cold start as well as she did before. Used to, I could turn and hold the key activating the choke and she would fire right up after a couple revolutions. Now it takes a process of that plus moving throttle a few degrees open, and about 5-minutes on the boat ramp.

Any suggestions are welcomed, as I'm not giving up!

i had the same issue.
Long story, but the starter motor wasn't turning over as fast as it used to. Cleaned battery and starter terminals with no improvement. Tests of the solenoid turned up marginal so I replaced the starter solenoid with no improvement. Was going to rebuild the starter but found a couple of burnt windings pon the armature. Installed new starter and cranking rpm is noticeably higher than before.

Starts with the turn of the key

 

[Norsemen9]

Yes, I did use OEM Carb Kits, and followed the instructions in the Service Manual to a T. I'm starting to question the chocking mechanism, and maybe the hose clamps on the Fuel Pump. I reused the metal spring ones on fuel out & pulse-in, but replaced the plastic push-catch ones with plastic pull ties.

 

[Norsemen9]

Thanks for the Starter info, I have noticed it "zinging" (for lack of a better term). The situation where the key is still in the start position but the starter is no longer turning the motor over. It happens more often when it's flooded with fuel.

 

[w2much]

Also be certain the side plates on the carbs are not leaking air. With the engine running spray starter fluid or wd 40 around the carb outside bodies . Had the same issue after a carb rebuild recently.. The side metal plates were warped so I needed to tighten them down .

 

[Norsemen9]

Want to thank everyone for their sound advice! ...I will check the plates on the sides for leaks, but had one last question.

I noticed when installing​ the Carbs that several of the 5/16" Fuel Lines that attach to the Carbs from the plastic Fuel Manifold were tight and bent pretty sharply. Is it possible that at low idle, when the fuel pump is only receiving a pulse ever so often, that the Carb's could starve for fuel? Is there any reason not to replace these lines and be a bit more liberal with the length ?

 

[cfauvel]

I assume you have the plastic carbs...right?
when you had the bowls off and were doing the needle/seat...did you install a nylon washer under the seat? if yes, did the area where the seat screws into have a raised lip? From what I understand that nylon washer is only to be used IF you don't have the raised lip where the seat screws into.

Yes all hoses to all carbs should have NO kinks

get some MAF or carb cleaner and clean off all the hoses and connections so that they are all dry.

replace the zip ties with the proper sized Snap Clamps (various sizes, #6 for oil line, and I think #8 and #10 for fuel lines) the only zip ties I see being called for are the ones at the carbs' inlet.


Pump the primer bulb and look for fuel leakage at each carb, at the fuel distribution manifold (a little plastic thing with 6 outlets to each carb), and at the fuel pump.


You did the link/synch right?, the butterflies are completely closed at idle right?