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Ocean Runner 225 Idle Mixture Adjustment and Recirculation System Questions

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beatnavy

Member
I've got a '94 Ocean Runner 225 (J225TXERK) that I'm trying to keep running. About a month ago I rebuilt the carbs for no particular reason except that I thought it would be good maintenance, and idle has been a bit rough at times, like sometimes it's touch and go coming in to dock (I've already damaged and repaired the bow once when I stalled and couldn't slow down enough - don't want that happening again).

After the carb rebuild, I did a lync and sync per the OEM manual. I set the idle mixture at 2 1/2 turns initially, and I tried to adjust each carb a little leaner, as I always thought it had been running too rich. I set idle timing at 4 ATDC (it was too far advanced) and a couple of days ago I had my neighbor help me set max advance while WOT. It starts great and was running like a champ, and everything was cool until we almost got back to my dock, and then idle started dying, and the motor would sneeze. Eventually it did die and was a real pain to get restarted (my wife actually towed us with a kayak the last 100 feet to the dock). At the dock I eventually got it restarted, but it would idle very smoothly until all of a sudden it would sneeze a bit, the idle would drop, and it would die. I did this several times.

Based on the sneeze, I started adjusting the carbs a bit richer slowly and that seemed to help. Next day I took it out, ran it at WOT for a couple of minutes, and it still wanted to die idling back in to the dock after idling very smoothly for a minute or two beforehand. Got it back to dock (no tow by wife this time), and it still kind of wanted to do the same thing: idle very nicely for a few minutes but then with no warning, perhaps a sneeze and a drop in RPM's and it would die. A couple of very slight adjustments on the idle mixture to make it even a bit richer, and that seemed to help again. Today I fired it up at the dock -- she started right up and idled great. No sneezing or dying - but then I didn't take her out and really run her.

So, I apologize for the long back story, but here are my questions:

1. Does this sound like an idle mixture issue possibly? I find the OEM manual's process for mixture adjustment a bit confusing and would like clarification on that. Do you adjust and test each carb individually (e.g., adjust, run at idle, run at WOT, repeat on next carb)? Should all carbs basically have the same adjustment or is that not the goal? Any elaboration on this process would be helpful.

2. Could this be a recirculation / check valve issue? I have no idea if those have ever been serviced or cleaned.

3. What else should I focus on as most likely suspect(s)?

TIA

rc
 
It's the OMC Johnson Outboard service manual. It says on page 2-31 under Carburetor Mixture Adjustment "The needle's initial reference setting is 2 1/2 turns off its seat."

I've read 5 turns on this forum before, but I've also read that there are different methods depending on model. On mine clockwise is richer, CCW is leaner. Before I rebuilt the carbs whoever had worked on the motor in the past had them set pretty rich (e.g., less than 2 turns out).
 
Nothing? Ok, more info. I took it out today, ran it at WOT for a short period. The tachometer has always been intermittent for me (sometimes I get tach at first startup and at throttle but beyond that zippy), and the voltage readings are often erratic. When I was running it today I was getting voltage readings above 16 volts. Not good. After bouncing around it settled in around 12.5 volts. I replaced the rectifier about 3 years ago and the powerpack last year.

Coming in to my dock at idle speed in forward gear it did the same thing: stumbled and died. Getting it restarted was easier. Once I had it tied up at the dock, I fired it back up and it idled very smoothly until I shut it down.

Why does this happen after running at WOT for a few minutes? I'm trying to understand what's going on here with fuel delivery.

Can someone provide a more "see spot run" reference for carb mixture adjustment?

Tomorrow I'm going to see if I can understand this recirculation system a bit more. My plan now is also to inspect the battery cables and battery switch more thoroughly to see if a problem lies therein before buying another rectifier.
 
Does it have the adjustment at the top left of carb like pic below??? If so that is not a idle adjustment its a fine tune for the intermediate circuit...
junkrude carb.jpeg
 
In response to faztbullet, that looks like my carb setup, but here's what it looks like with the silencer on: idle AIR adjustment (CCW Lean, CW Rich). So if that's not what I'm supposed to be adjusting, what should I be doing?

Rwbutler: no, I really didn't unfortunately. I mean I sprayed carb cleaner in and around, but in retrospect I should have removed the whole assembly, shouldn't I?

IdleMixture.jpg
 
I do remember spraying carb cleaner into those ports until I was sure there was cleaner coming out through those ports, now that I think about it. But that's really all I did on the TB side.
 
More info. This finally caught my eye. It looks like the starboard temp switch connection is bollocksed up. I tried to create a temporary connection to see if that made a difference, and it was hard to tell. Starting the motor today it definitely wanted to stall a few times at idle. Again, it will be idling seemingly fine and then something almost "catches," idle slows, and then it coughs or sneezes to a stop. When it was a little warm, I disconnected the port side temp switch to see if there was any change and it didn't seem like it.

I need to research what an open connection on a temp switch does. The way the idle drops and dies suddenly does have me wondering if this isn't electrical related somehow.

TempSwitchLead.jpg
 
A disconnected temp wire willnot affect ignition or carburetors.
If your carb side covers have four screws,install a fender washer on the middle screw.
 
As mentioned earlier cleaning out the throttle bodies. You have to get behind the small cover plates and clean the tiny orifices located there. At least that is how it is on my 97 Ocean Runner.

A few other things to check:


  • Molded hoses going from the fuel rail to the carbs. As they get old they also get soft and if not re-installed very carefully can fold or pinch causing a fuel restriction.
  • More on fuel lines.... I replaced all of the hodge podge of tie wraps, spring clamps and worm drive clamps with double snap grip black nylon hose clamps. I did this from my fuel tank back to the motor. Double clamped where possible.
  • Re-circulation lines - While de-carbbing I noticed some bubbling coming from my No. 2 Cyl. nipple. I pulled the hose, wire brushed the nipple sprayed clean, tested the line and check valve with Isopropal alcohol and a medical syringe. After testing I put it back together with mini snap grip clamps (I got the assortment box on Amazon)....I did this for the other 5 lines. I have not yet done the upper and lower crank bearing lines. Probably will eventually.
  • Did you check the carb bowls for warping? You can fix this by sanding them on a piece of glass, or cast table saw deck.
  • Did you properly torque the plastic carburetors to the throttle bodies? this has been identified as a potential problem.
  • the small brass tubes in the carb interior. They can become obstructed. I cleaned with a welding torch tip cleaner. This is the pickup for the idle circuit.
  • Plastic washers on the needle seat. they come in the kits, but not all carbs use them. You need to check because they will cause problems if installed and your carbs were not designed to use them.
  • Engine mounted fuel filter. Make sure if it's a cleanable filter that it seals well. I replaced the glass see thru filter I had which had several potential leak sources with a sealed 1 use disposable filter.

I went through this a few months ago and it's frustrating. Go down the list and eliminate as many items as you can as being a potential problem source. It's crazy how a small item easily overlooked can cause problems. And this list is by no means all inclusive. Good luck!
 
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Cable Mariner, thanks for the input. It is frustrating. I did replace the gasket during the rebuild, but I did notice that those plates don't look like they are perfectly flush in some cases, so I guess putting on something like a fender washer can't hurt. It looks like I can do that on 4 of the 6 carbs without removal. In any event, it still looks like they're all going to come off again, along with the throttle bodies, for more inspection / cleaning. I guess at that point I can also try to inspect and clean or replace the recirc valves as well, right?
 
beatnavy said:
Cable Mariner, thanks for the input. It is frustrating. I did replace the gasket during the rebuild, but I did notice that those plates don't look like they are perfectly flush in some cases, so I guess putting on something like a fender washer can't hurt. It looks like I can do that on 4 of the 6 carbs without removal. In any event, it still looks like they're all going to come off again, along with the throttle bodies, for more inspection / cleaning. I guess at that point I can also try to inspect and clean or replace the recirc valves as well, right?
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For the re-circulation lines. disconnect at the cylinder nipple and using a medical syringe try to push some Isopropal Alcohol through the tube. As long as it flows through you are good to go. If it's plugged they make a cleaning tool for the check valves. On an old motor like that I would not attempt removing unless absolutely necessary. It could open a bigger can or worms. You just want then to work.
 
I also see that on your throttle bodies you have the replaceable core plug that covers the idle circuit passages on the throttle body instead of the plate and gasket. Might want to do some more research on cleaning these passages. I read on another thread where some people drilled these out and used a tapping screw to pull the plugs out, cleaned in there and then installed new ones. Agin my motor is different so I have no experience with this type. Now you can cheat a little by directing the little red tube that comes with a can of carburetor spray into the air oriface and blasting liberally with the engine off. Expect to burn about a whole can of carb cleaner between all 6 cylinders. It's kind of a cheat but better than nothing.
 
Back to the adjustment screw...it should be set about 2 turns out. Despite the decal labeling what it does is richen/lean the transition between idle and intermediate range. Idle mixture controlled by jet in carb. Make sure the 2 jets on left side of carb has the smallest # in lower and largest in the top position.
 
Ok, zero steps forward, two steps backwards :( After futzing with the carbs today I can't even get it to idle.

So, as a rundown, I did the following:

1. Took each carb off and sprayed all the orifices on the carb and throttle body liberally with carb cleaner. Made sure to note that cleaner was entering / exiting the correct (hopefully) orifices and none were clogged.

2. Verified that the jets on the left side of carb are smallest lower / largest higher.

3. Added fender washers to all size side plate center screws and torqued those down.

4. Made sure fuel lines weren't kinked or otherwise bollocksed up.

5. Set the idle/intermediate screw to 2 turns off seat as per faztbullet's recommendation. They had probably been around 3 or slightly more turns out when I first started trying to tune them, and as of yesterday they were roughly 2 1/2 turns. Now they are at 2.

6. Torqued the carb to TB at the proper spec, which I BELIEVE is 45 to 55 in-lb's, correct?

I did struggle getting those darn carb seal gaskets to sit properly in the channel after taking the carbs off. I did NOT remove the fuel lines and that properly made it harder to ensure those things were seated properly before torqueing the carb onto the TB. That may be causing me problems, and maybe I have to order new ones again and figure out how to get those to stay put.

It's hard to tell if my problem was too rich or too lean at this point, and my knees had kind of had it, and mentally I was ready for Miller time. I suppose I'll order more seals and get back at it. I'm running out of boating season and need to look at putting it into storage before too much longer. Would like to just get it acceptably running at this point, and then I could pick it back up in the spring.
 
Oh, and I did pick up some 1/8 in ID tubing and a syringe. But couldn't find any isopropyl alcohol (apparently it's being horded right now). So I didn't mess with the recirc components.
 
You can put a light coating of grease on the carb spaghetti gaskets. This will help them stay in their grooves.

Also, After going through all this I might also suggest performing a seafoam decarb shock treatment. External tank with 3/4 Gallon gas and 1 can of seafoam. Run it through and install new plugs after the decarb properly gapped to 0.030. Basically you are going to keep doing positive things and ruling out sources of problems.

If you still have problems after all of this I would think about getting a piece of clear 3/8" hose. You can start by putting this inline starting at the VRO inlet. If you have any air leaks into the fuel system they will be visible. If you find air bubbles you can move the hose back towards the tank in steps until you isolate the leak.

Finally if all of this fails you may want to look at the VRO. The manual has testing procedures for the fuel pump side of it. there is a remote possibility of a bad diaphram but those problems are usually evident at speed not at idle so I would save that option for last.

Again, I know it's frustrating. Old engines have so many things that gradually deteriate and fail just because of age. On another forum one guy had a lean condition from a hairline crack in the fuel rail. Something like that can take a real sharp eye to spot. So scrutinize everything. You could be looking right at the problem and just not seeing it. I have my powerhead running awesome now after being in your shoes. I'm now trying to figure out a vibration that I suspect is coming from the lower unit. I'm not looking forward to the work involved in resolving it.
 
Thanks for the input and help all. I did rebuild the VRO last year, and it was running ok, but I honestly don't think I have 100% confidence in it. I tried the clear oil tube and counting pulses test last year, and I think it seemed ok. Do I buy a new OEM one (~$500), an aftermarket one (~$150), run pre-mix, or just go with it for now? I don't know for sure, except I'd really prefer not to run pre-mix if at all possible. Gotta give this one some thought.

Today it fired up and actually held an idle, even if it was sort of rough. When I put it in fast idle just to open the throttles some, it ran rough and was spitting fuel. Shut 'er down, took the carbs off, and at least one of the "spaghetti" gaskets was in fact torn, and another looked like it was probably pinched in the channel. Didn't see anything else obviously wrong. I have new gaskets, fuel hose, and those side seals on order. When I took the carbs off and started looking at those plates, it looked like the seals were also getting deformed, probably because I torqued them down too much.

I ran a bunch of cleaner through the ports on the TB again. At this point is it worth removing the TB assemblies? I've got a few days to wait for parts, so I guess I could focus somewhere other than carbs for a couple of days.
 
If you had gaskets that were not properly seating/sealing that could be your entire problem right there. You would do well to get that corrected first before attempting any other problems. This is a real issue, the others could be ghost issues. Coat the spaghetti seals with grease when you put them back on. That will stick them in their grooves. Carry on once you know you are 100% on this.
 
I don't think that gasket was torn until I removed the carb the day before, but I could be wrong. It was definitely part of the problem in the last two days.

What's required in way of parts / process to remove throttle bodies. Now that I have some time to wait, I was considering going ahead and trying to clean / test the recirc valves, even though I'm not REALLY showing classic symptoms of problem there (no fouling on lower spark plugs, not really hard to start, etc.). Found some isopropyl alcohol today. Is this much easier with TB off?

I do have the gaskets. It looks deceptively easy to remove them (i.e., a couple of linkage screws), or is that not the case?
 
If you look in your service manual,it will tell/show you how to check recirc system.
Your TB's are probably ok if you have sprayed thru and got equal spray out.
A good inspection of the reed plates is recommended. check reed plate gaskets.should be eight Phillips head screws..
 
Ok, I'm back with an update and not a happy face. Received new side plate gaskets and spaghetti gaskets as well as one float bowl gasket to replace the one that looked a little tweaked. I ordered fuel hose for the fuel rail to carbs, but apparently I didn't order the right part(s). So I had to reuse what I had.

I cleaned the carbs again thoroughly, replaced the gaskets, checked float bowl level, etc. Carefully reassembled to the throttle body making sure spaghetti gaskets stayed in place. Put new zip tie holders on fuel lines even if I couldn't replace the lines.

I couldn't get an idle to hold. It kept dying on me. I fiddled with the idle mixture screw leaner and richer, but it was pretty much the same. I could get it to start and hold for a few seconds, but then it would die. I could keep it running at some significant throttle, but if I even got close to having the throttle plates mostly closed it would die. I noticed minor leaking or seepage from the number 6 carb float bowl, so I removed that and tried sanding the float bowl on a piece of glass. I thought it got better even if the plastic parts do not seal perfectly together. Several of the carbs have small gaps at different points around the float bowl seal, but only this one showed signs of leaking. Once I put the number 6 back on it still may have seeped a little.

By the end of my effort today I was getting the same behavior consistently: crank the engine, it would fire right up and sound strong and fast, idle for roughly 5 to 6 seconds, then cough and die. I did this a dozen times with same result.

Other than taking all the carbs off and sanding down the float bowls, I'm at a bit of a loss as to what to try next :(. It does seem like the side plates don't necessarily sit flush against the carb body either. I'm hoping the gasket in there is doing it's thing, but that doesn't give me tremendous confidence when I see a small gap there.
 
Went out again today. Blew some carb cleaner through the jets again just to try and make sure none of the grease I used was blocking the orifices. Same behavior - fires right up, idles strong for about 5 seconds, then drops and dies. Then I decided to remove the fender washers I put on the side plates. Kind of grasping, but I thought maybe there's a chance they are somehow interfering with those channels / ports in the carb body underneath. I'm not sure about cause and effect, but I was able to get a solid idle for about 5 minutes, purring like a kitten, until rain came through and eventually chased me inside. My reasoning was that I was able to get an idle before I did some changes, like putting those on, so why not try and undo that? Again, not sure why that could be an issue, and maybe it wasn't.

I'm now wondering if some of this is charging system related. When the engine was purring I had a voltmeter reading solidly in the green, whereas before when it would repeatedly die it was well into the yellow. My VR/rectifier (whichever one it is), voltmeter, and tachometer have always baffled me a little. They are always intermittent. Most of the time I don't get any tach reading, and the voltage readings can sometimes look good and other times be all over the place. I replaced the VR/rectifier a couple of years ago, and I remember the tach seemed to work after that, for a while anyway. When it stops raining I'll do some more testing to see if there's a correlation. In the meantime I'm going to do some reading up on the charging and electrical aspects of this...
 
beatnavy said:
Went out again today. Blew some carb cleaner through the jets again just to try and make sure none of the grease I used was blocking the orifices. Same behavior - fires right up, idles strong for about 5 seconds, then drops and dies. Then I decided to remove the fender washers I put on the side plates. Kind of grasping, but I thought maybe there's a chance they are somehow interfering with those channels / ports in the carb body underneath. I'm not sure about cause and effect, but I was able to get a solid idle for about 5 minutes, purring like a kitten, until rain came through and eventually chased me inside. My reasoning was that I was able to get an idle before I did some changes, like putting those on, so why not try and undo that? Again, not sure why that could be an issue, and maybe it wasn't.

I'm now wondering if some of this is charging system related. When the engine was purring I had a voltmeter reading solidly in the green, whereas before when it would repeatedly die it was well into the yellow. My VR/rectifier (whichever one it is), voltmeter, and tachometer have always baffled me a little. They are always intermittent. Most of the time I don't get any tach reading, and the voltage readings can sometimes look good and other times be all over the place. I replaced the VR/rectifier a couple of years ago, and I remember the tach seemed to work after that, for a while anyway. When it stops raining I'll do some more testing to see if there's a correlation. In the meantime I'm going to do some reading up on the charging and electrical aspects of this...
Click to expand...
What did this end up being? I am having all of these same symptoms exactly.
 
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