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1994 j140txarc

N

nehringer

New member
Got both motors checked by mechanic when I bought the boat and both motors passed. Ran it out once and the starboard motor wouldn't start. Limped home, changed filter, plugs and wires and it fired right up. Took it out again and now it won't run for more than a minute. Took it back to the mechanic to have the carbs rebuilt. He checked it over again and found that it wasn't firing on all four. Said the power pack was bad. Replaced power pack. He rebuilt the carbs and was about to tune them when the motor wouldn't run on its own. All of the sudden, it's not making power on one side so the stator was bad. Replaced the stator. Now we have fire to all four and good voltage. Ignition timing was re-set and even when its running ragged, the timing is still good. Discovered that the fule pump was passing fuel through the pulsating side. Removed and disassembled the pump and found the diaphragm was torn and dry rotted. Rebuilt the fuel pump, reinstalled it and still had the same problem. Replaced the fuel pump. This is a VRO pump with the oil side plugged with a bolt. Running mixed gas through a new Racor. Other motor runs just fine on the same fuel. Not bad gas. Engine still sputtering and backfiring at idle. Pulled the manifold and inspected the reed boxes. No light coming through, so they were cleaned and re-installed. Pulled the flywheel off to see if the shear pin had failed. Nope. Still coughing, racing and backfiring. Choked off each carburetor one at a time and 3 of the four will kill it when choked, one has no affect. We did this a couple of times and the carb with no affect jumps around. In other words, it's not the same carb. There is an intake air leak somewhere. The mechanic wants to pull the power head off and check the crank case seal next. I'm already in it for considerable maintenance hours and this proposed job is going to take another 5-6 hours, just to trouble shoot. It may or may not be the solution to the problem. What else could it possibly be??? I'm looking to hear from former OMC tech-reps or someone else who has had this same thing happen and what was done to fix it. My mechanic has been working on OMC's for 35 years, has been to all of the schools and comes highly recommended locally as "THE" guy. However, this problem has him ripping his hair out and emptying my wallet! I would love to hear that this is something simple staring us right in the face, or that changing the crankcase seal IS the right fix. I'll go through with it if I know in advance that this procedure should work. But if it's just another "check and see" then I'm not so sure I want to mess with the expense. The motors have pretty low time for their age and are both making 125 psi on all cylinders with no leak down. The lower units are fresh and I have no reason to believe that they won't last a long time once this is fixed. I'd hate to have to replace them over something that maybe a simple matter of a seal. Please, HELP!
 
The faulty carburetor thing..... it is impossible for a functioning carburetor to malfunction intermitently, that is to have #1 carburetor fail, then function properly, passing the malfunction along to #3 or #4 carburetor etc. That just doesn't happen.

But what can happen is that the ignition is malfunctioning, affecting various coils etc. This would give you the same effect as having the carburetors act as you describe..... if #2 isn't firing, choking off #2 carburetor will have no effect.

Check all connections leading from the timer base to the powerpack, and from the powerpack to the coils. Those rubber connection plugs (sockets/pin terminals) have a habit of having the pins/sockets back away from each other. This results in a poor or non existent connection. Also the wires that connect to those pins/sockets have been know to break away from the pins/sockets which again..... leads to a poor or non existent connection BUT appears to be connected as the wire is still held tight in the end of the rubber connector. Check all ignition related wiring for fraying, loose grounds, tight but dirty grounds etc.

Your mentioned compression (125 psi) is okay.

With the spark plugs removed, the spark should jump a 7/16" gap with a strong blue lightning like flame.... a real SNAP! The 7'16" gap is important. If no tester, build this one.

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
　
..........X1..........X2
.................X..(grd)
..........X3..........X4

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:
http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1

Check the continuity of the coils as follows.

(Magneto Capacitance Discharge Coils - Continuity Test))
(J. Reeves)

Check the continuity of the ignition coils. Remove the primary orange wire from whatever it's connected to. It may be connected to a powerpack screw type terminal, a rubber plug connector, or it may simply plug onto a small boss terminal of the coil itself.

Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground of the coil or the powerhead itself if the coil is still installed.

Then touch (still with the red lead) the orange wire if it's attached to the coil, or if it's not attached, touch the primary stud of the coil. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire. Poor or no continuity of a coil is one reason for s/plug fouling.

----------------------

The center underside portion of the flywheel of the older 1992 models was the magnetic triggering device... a north and south pole gap in a ring that triggered SCL switches within the powerpack to fire the coils (I retired a few years prior to your engine being manufactured). If your 1994 model flywheel still incorporates this feature, look at that ring very closely. That magnetic setup is usually a epoxied setup which has been know to melt down somewhat (ever so slightly), not enough to keep the engine from running BUT enough to cause the ignition to be erratic, weird beyond belief.

Let us know what you find.
 
Thank you for the reply. I will pass the information along to my mechanic, but he is absolutely convinced it is not an ignition problem having replaced everything except the rectifier and coils. It wouldn't surprise me a bit that there is a poor connection between the new components and the old ones. He says that the carburetor is not "sucking gas" when he chokes it off which is what has him convinced that its a breathing problem. At first it was #2, then it was #1.

Having twins, we were able to take the flywheel off of the port motor and check that magnetic trigger. No change. He's tested the spark a few times and everything is firing. I've suggested a continuity test of the coils, but it's really not my place to tell him how to do his job! I respect his knowledge and experience, but this IS my money. The last thing I want to do is have him tear down the power head looking for something that maybe as simple as replacing the coils at $30 a piece. My most recent experience has been with a troublesome inboard and the theory of operation is a little different. I've had several outboards and had my share of issues with them, but I have always been able to fix it myself. This is something that exceeds my ability, so I sort of feel as if I am at his mercy. I'm very fortunate in that he has allowed me to watch and even assist a little so I have seen all of this with my own eyes. Hopefully you're on the money and we can sort this out without major exploratory surgery.
 
Still no solution. Everything electrical is checking out. Engine acts as if it is idling lean, and then dies as if it is starving for fuel. Carburetor bowls are filling up. Mixture screws have gone in and out with no change. Timing is dead on under the light. It's gotta be a vacuum leak, but where?
 
I don't know. It would continue to run like that before the pump was replaced, but I wasn't there when he ran it up yesterday so I can't say. I got there about an hour after it was run the last time. I tried pumping the bulb with the motor off, and I noticed that it wasn't staying firm and I couldn't hear fuel moving. I opened the primer solenoid manually to vent the pressure and I saw fuel leaking from somewhere between the primer solenoid and the carburetors. What does this tell us?

I'm still concerned about the electrical integrity. Everything was fine at one time. Then the power pack went out; then the stator. Now all of this...We're still not sure if it's timing, fuel or air. If this thing is frying out electrical components, shouldn't that indicate a short? Something seems to be in conflict. He tested everything in the ignition system yesterday and says that it all checked out. I'm still concerned about an air leak, but the more I read into it, the more I learn just how unusual a significant air leak can be. It's gotta be a fuel delivery problem, right? With a new pump and rebuilt carburetors, I don't know what else there is along that path that could be compromised.
 
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Pumping the fuel primer bulb with the engine not running....... bulb does not get hard. Remove the carburetor face plate so that you can observe the carburetors.

If fuel flows from any of the carburetors, then obviously the carburetor is at fault. If none of the carbureors flood (leak), clamp the fuel line shut with vice grips or some such tool, then pump the fuel primer bulb again. If the bulb now gets hard, a leakage exists at the engine somewhere. If the bulb still doesn't get hard, the fault is usually with the bulb's valves.

Opening the primer solenoid...... I assume that you mean that you're turning the primer solenoid's red lever to the manual open position. Any leakage between the solenoid and the carburetor area indicates that either one of the small primer hoses is faulty or is not connected to its fitting.

Possible electrical short(s)......... Always a possibility. You'll need a electrical diagram of that engine to study. It will become obvious what should have voltage applied to it and what should not. The diagram is no doubt available on this site. See the top area of the previous page..... the "Sticky" entry. Hopefully it's available.
 
Okay...here's the status. It's working, but with issues. I was informed that he had "forgotten" to try installing four little screws into the jets. He said that this would enrich the mixture at idle. He got it idling on the hose and left it up to me to take it out on the water. He was able to obtain the response from the carburetors that he was looking for all this time and said that I would probably have to "play with it" to keep it idling in neutral. Sure enough, it takes a little throttle to keep the engine alive in neutral. However, in gear it seems pretty happy at 750 rpm. It runs smoothly through the entire throttle range up to WOT and peaks out at about 5800, (15X17 wheel). I know that the only way to adjust the carburetors properly is in the water, but there still seems to be something not quite right. It should warm up and idle with the throttle in the center neutral detent. The other one does! I'm really hoping that this is all a matter now of simply adjusting and re-adjusting the mixture and control linkages to get it in a happy place. Meanwhile, as long as I have a way of keeping it alive from the helm, I will finally be able to salvage what's left of my vacation.

Oh, the primer solenoid...I think we narrowed that down to a bad O ring. It's still firing on all four cylinders, indicating 12V on the volt meter and is not doing anything when the primer bulb is squeezed while running.
 
Read your latest PM. That "mechanic" is a real gem. Hopefully some knowledgeable tech jumps in here with a quick carb adjustment procedure for you.
 
Loosen all throttle linkage so the throttle plates are completely closed.
Set all mix screws about 2,5-3 turns out.
Start the engine and let it warm up properly.
Check for even temp at both banks.
reduce ignition advance to as low as possible (links still loose, plates closed) with engine running.
Turn each screw in about 1/8 turn at the time, until that cylinder starts to 'sneeze', then back off 1/4 -1/2.
When finished all 4 cylinders/carbs, tighten linkage and set pick-up timing according to manual.
If any of the screws are more than 3/4 turn off in setting compared to the others, you probably have a damaged seat in the throttle plate housing.
 
joereeves said:
Read your latest PM. That "mechanic" is a real gem. Hopefully some knowledgeable tech jumps in here with a quick carb adjustment procedure for you.
Click to expand...

wow....this is bizarre.

what does this mean?

" I was informed that he had "forgotten" to try installing four little screws into the jets. He said that this would enrich the mixture at idle. "

Plug all idle bleed jets with a screw? Wow.

New mechanic time, I think.
 
Apparently my mind was wandering elsewhere due to a zillion things I've got going around the house, yard, shop, etc. Daselbee's reply entry jogged me back to exactly what was said above..... "forgotten to try installing four little screws into the jets".

Looking directly at the carburetor face(s), there are two small jets located on the left front side of the carburetor. The top one is the "intermediate air bleed jet", the bottom one is the "idle air bleed jet". Notice that they measure air, not fuel. If that fellow actually forced in a screw into either of those jets, most likely the idle air bleed jets..... that simply closes off the needed air supply which forces more fuel into the crankcase, destroying the jets in the process. Needless to say, this does not cure the problem. It's more like running a engine with the choke half closed rather than clean and rebuild the carburetor...... makeshift!

I don't know what the size of the jets should be but the size will be marked on the face of the jets such as 31=.031, 16=.016, etc. The larger of the two sizes (whatever they are) would be the top (intermediate) one.

A thought..... there should be a thick black rubberized gasket on the back of the carburetor face plate that presses up against the carburetors (acts a a air restrictor). If that thick gasket is missing, the engine runs lean resulting in weird happenings.

Don't let that character anywhere near your chopper.
 
Gentlemen, I thank you. Having had more than my share of boat problems, I now find myself at the mercy of those more experienced than I. I'm not an idiot. Let me get that out of the way to start. I understand the theory of internal combustion engines. I also understand the theory of gas turbine engines...an area in which I excel. However, for some reason, the theory of internal combustion two stroke outboards eludes me. A phenomenon which I cannot explain. I am learning, however. I've had several outboards and this is the first that I have encountered such difficulty with.

This guy, no matter how highly recommended, is off my list. He not only consumed every cent of my vacation allowance, he reduced my intelligence and kept me from catching the fish to which I was entitled. I understand that everyone has a bad day. But this guy is a douche bag. I was fully prepared to leave benefit of the doubt, but he has reduced my tolerance dramatically.

The motor is running and I have figured out a way to keep it from dying on me. I had the boat out all day and as long as I kept the RPM's up at idle, I was able to engage the gear without slamming it. I followed the prescribed procedure for adjusting the mixture and it seemed to work better...although not completely. I would rather idle at 1000 ROM than 750 in neutral, but in gear, it's happy at 750...for a little while.

Now comes a new problem...neither engine is charging the battery. At first, both engines were indicating 12V on the volt meters. I watched the volt meters decay to nothing as I was running about the bay. I ended up having to wrap the string around #1 and it started right up, (thank you baby Jesus). This was my very first time attempting to start with the pull cord and I was very pleased at the result. However, I am befuddled that both engines are indicating good voltage but the batteries are dying on me.

I'm prepared to do whatever is necessary in order to get #1 working as well as #2. Even if it means having to take the dude to court. I would of course have to prove that he was negligent. Next, comes the electrical issue and why the motors aren't chrging the batteries. Much of this falls on the previous owner, as far as I'm concerned. He's not a mechanic and I think he has been pretty straight with me about the history of the boat. I don't think he is all that mechanically inclined but I think he knows that he's had some problems that he's not telling me. The wiring of the battery switches is insane! There are two, 3 position switches, (1, 2, both) hooked up between two motors, two starting and one house battery. There is also a 3 bank battery charger which I think is fried. Gotta get into that later. The PO tells me that he has always run the boat with the switches in "both" so that all three batteries would charge simultaneously. I don't think that is happening. I've got them on a trickle charger right now. After three weeks in the shop, no charge going to the starting batteries, it lasted almost all day. I'm thinking that after a good home-charging, it will last a whole day on the water.

So, home charging batteries, feathering the throttle to maintain RPM, this boat is basically a bandaid in the water! I have all of my life jackets, eperb and float plan ready to go. I also have a tool kit which, to some, may seem over the top. I'm ready for anything. I would just feel better knowing that I've got the ability to fix whatever maybe wrong, or could go wrong.
 
wow, welcome to the world of professional marine mech.'s the guy's I read on this site are by far the most knowledgeable & straight forward about what is probably wrong with your engines, without looking at them personally. I have experienced a "pro" mech. recently myself & it left me with some very dubious feelings about the breed. Treated me almost like I was a women at a auto garage. I'm sure there are good ones somewhere. I havn't found one local yet. Listen to these guys, & you'll be money & time ahead. best of luck, jeff
 
Be optimistic.
I traveled 20.000 N Miles, mainly by wind so nothing is impossible.
As for idle:
On the throttle arm that opens the carbs, it is a cam. That cam has a markarrow.
As you increase the throttle, the ignition advances and cam moves. Adjust the carb linkages so the carbs starts to open JUST as that mark is at the carb roller.
I have a feeling that even your pick-up timing should be checked. (the timing when the mark hits the roller)
Charging.
Are your tachs working???
May look like it as you have indicated an idle speed.
It might perhaps be easier to re-do the main battery switch system than trying to figure out how he has connected it all.
On the engine start solenoid where the battery cables connect, it should even be another RED wire coming from the regulator in the block behind your fly-wheel???
If we are 'lucky'. the previous owner has re-routed that somewhere else. Put it back!
Start the engine and check the voltage.
 
I just installed two new tachs. One is working, the other isn't, but it has voltage going to it and the gray wire indicates varying changes in output as I increase and decrease throttle. It's gotta be the gauge. I'm taking today to do some "tightening up".

One thing I forgot to mention last night, because I wasn't sure if it was significant or not is that #2 makes more bubbles that #1 at the same RPM. Compression is the same on both motors. It just seems to me that there is more air coming out of one than the other. This whole thing has literally driven me batty; I maybe a little paranoid now! It's time to find a good SHRINK!!!
 
Let me then add some more salt.
The tachs are working off the charging system, and if you have a tach problem in addition to charge problems, most likely even your regulators are shot!
Out from the fly-wheel, two yellow wires are going to the regulator.
One has a gray stripe.
This is basically the same as the gray running to your tach, but with reduced amps (Going through the regulator).
Make a short test and connect the gray signal wire to tach directly to the yellow/gray.
Note: only short test, not permanent!!!!!!
If tach works from yellow/gray and not directly from gray, invest in a flywheel puller and 2 new regulators.
 
Joe...I hope you know I was referring to how "bizarre" the mechanic's debug procedures are, nothing you said at all.

I think, not sure, that the mech was suggesting removing the idle bleed jets, and putting a screw in there to block air flow.
Sort of like the toothpick trick to block an air jet temporarily.

I am not really sure what is going on with the OPs engine, but I am absolutely sure the "mechanic" does not know.

I REALLY REALLY like Morton's carb adjust technique. I mean REALLY!!!! That one is going into my mental toolbox for sure. What is so great about it is the deliberate idle timing adjustment to get idling as slow as possible. I can absolutely see that the effects of turning the idle screws would then be magnified, and more easily set. The books say to do the same type of adjusting, but they DONT SAY TO REDUCE THE IDLE SPEED while setting the idle mix screws. Great!!!
 
Thank you Daselbee.
When finished the idle setting, you may even perform a balance check of the engines 'lower' condition.
When running smoothly at idle, or if not running smoothly at one or more cyl, use a carb synch tool.
Equal plunger lift on all carbs and idle mix screw at same setting, indicates a perfect balanced crank case and reed valves.
If significant lower at one, the mix screw will normally have to be more 'out' to compensate lower air-speed.
This may indicate/eliminate:
Loss of vacuum, leaking reed valves below piston, but carb is ok, scored cyl lower part, leaking crankshaft seals etc.
If 2 adjoining cyls are low, it is likely the crank seal between.
A little 'testing' may save a lot of unnecessary work and parts changing.
A comp test only takes care of condition from upper piston ring and up when passing the exhaust port, this may help to establish condition below.
3504025.jpg
 
The engine is still running like crap at idle. I tried tweaking it a little according to your instructions, but without a manual and timing light, I am not fully able to do it right. One thing that has helped a little is I adjusted the throttle lever screws so that it idles a little faster. It is still sputtering quite a bit and again, I noticed a higher exhaust volume on #1 than #2, (more bubbles in the water). I don't know if that bears any significance or not.

If I had a bad crankcase seal, I think I would be having some water in the cylinders. This isn't happening as far as I can tell. The mixture is pretty rich from what I can tell, but it backfires and eventually dies at lower RPM's. As long as I keep it at or above 1000, it keeps running, but rough. It's also surging a bit until it gets good and warmed up... not bad, just slightly. It's as if it is trying to kick down, but starts to starve and it revs up on its own.

I've talked to some of the folks around here who recommended the guy and they all feel bad about my situation, but they are still pretty confident that he knows what he is doing. IMO, someone with so many years of experience oughtta be able to rebuild, sync and adjust two stroke carburetors in his sleep. I wish I knew more about how the carbs are suppose to function. Maybe I could figure out how to fix it myself. I'd love to take it somewhere else and have them prove that the carbs are in fact the whole problem. That way I could maybe get some satisfaction on my bill with the other dude. I just don't have the chips right now after paying that knucklehead!
 
haffiman37 said:
Let me then add some more salt.
The tachs are working off the charging system, and if you have a tach problem in addition to charge problems, most likely even your regulators are shot!
Out from the fly-wheel, two yellow wires are going to the regulator.
One has a gray stripe.
This is basically the same as the gray running to your tach, but with reduced amps (Going through the regulator).
Make a short test and connect the gray signal wire to tach directly to the yellow/gray.
Note: only short test, not permanent!!!!!!
If tach works from yellow/gray and not directly from gray, invest in a flywheel puller and 2 new regulators.
Click to expand...

Isn't the regulator located under the power pack? Do I really need to pull the flywheel to get it off? I'm looking at a parts diagram and I only see a rectifier/regulator assembly. I couldn't make heads or tails out of my ohm meter yesterday. I'm sure I did something wrong. I was previously informed by my wonderful, genius mechanic that the #2 engine was making good power. Before I start shopping for another repair shop, I'm going to find a good psychiatrist! This is making me absolutely nutty! I'm about to start saving up for a pair of new motors!
 
There are 6 crankcase/ crankshaft sealing rings. I have seen issues with these, as in badly worn and completely broken on more than one motor.-----------------The " mechanic " should check them out.
 
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