1987 Johnson J200TXCUC lost power

First off, I was underway and cruising at approx 4500rpm when the motor lost power and slowed to a stop then cut off immediately. I then let it set for 10 minutes and tried to start and as I turned the key all of the gauges/fish finder/gps would cut out and motor would not turn over. Maybe a coincidence but I turned battery switch to all and then it started. Motor sounded fine but as I got on plane and cruised at 3000rpm for 10 minutes it started to make a rattling noise and I slowed it to idle speed and limped back to dock. Anyone have any suggestions on where to begin? I haven't tried to start it for the last couple of days but was going to inspect spark plugs then do a compression check. Could it have been a dead battery while underway? Any info will be appreciated. Thanks

Re: 1987 Johnson J200TXCUC lost power

I hate to say it, but I think your engine is blown.
The symptom of being underway, and shutting down like that can be caused by a very lean running piston, which overheats, seizes to the cylinder, shutting the engine down due to the friction. Then, when it cools down, the piston returns to size, and the engine is free again. It doesn't take long at all for it to cool enough to turn over again.
It will start up, but you will find that the compression is very low in some of the cyls.
Now, the fact that it is rattling is bad news.

First, do a compression test. If low, remove the head(s) on the cylinders affected, and you will immediately see the cylinder damage.
Normal compression should be about 90- 100 psi.

Re: 1987 Johnson J200TXCUC lost power

First off, I was underway and cruising at approx 4500rpm

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Worst RPM to run a looper V-6 as it coming on the high speed jet. That one reason OMC installed the brass restrictor in bowl vent to richen up midrange and the hot rodders just tap it and install a high speed jet drilled to a little over 100 wire size

Re: 1987 Johnson J200TXCUC lost power

Thanks for the input. I will be able to inspect motor later this week. I would like to do the compression test myself/friend and wanted to perform check with ignition switch because I don't have jumper . I will purchase jumper if it is safer to use or recommended. What should I disconnect on this motor in order to check by bumping over by ignition switch, I have compression tool etc. This boat was a recent purchase and mechanic inspected motor for me previously. Just want to be able to know for future knowledge. Thanks again for your quick responses. I will keep you posted after motor inspection.

Re: 1987 Johnson J200TXCUC lost power

There are a several ways to proceed.

1. IF you have an emergency kill lanyard, and IF IT WORKS, you can pull it, and the engine will crank but not start,
because the ignition is disabled.

2. You can buy a remote start switch and hook one side to the + battery cable at the solenoid, and the other side
to the yellow/red wire on one of the small terminals of the solenoid. When you press the button, the engine will crank,
but the key is OFF, so it will not start.

3. You can cheaply perform the same function of the remote start switch by using a short piece of wire and jumping
between the same two terminals on the starter solenoid as mentioned above.

4. You can use a set of jumper cables directly from the battery. Hook the ground to a good solid unpainted place on the block,
and connect the positive directly to the hot lead on the starter, only when you wish the engine to turn over. The terminal on the starter will have a big red wire on it (5 inches long) that leads back to the starter solenoid.

5. You can just turn the key to start at the switch, with the plug wires disconnected. This is hazardous because there may be
stray gas fumes expelled from the open spark plug holes, and a plug wire may arc...and....you get the idea.

6. The last, and most difficult, is to go under the pack, look for the black/yellow kill wire, and ground the pack side of that wire.
That disables the ignition.

Re: 1987 Johnson J200TXCUC lost power

Update: I was able to check the plugs and they all looked clean, none were scorched or such. Plugs only have approx 30 hours. I know this is not going to give me any indication of what is going on but didn't have adequate time to perform compression check. As for the jumper wire to bump engine, I have attached a photo for discussion. Which wires on starter are used to bump engine if I were to use either a switch or wires? Thanks

Re: 1987 Johnson J200TXCUC lost power

The small terminal with white or yellow "dot" or paint of some kind is one terminal to jump.
The other terminal is the positive battery cable connection, which is that big white wire to the right of the terminal referenced above.

Jump those two with either a wire, or a remote starter switch, and the engine will turn over.

Re: 1987 Johnson J200TXCUC lost power

daselbee, thanks for reply. I will hopefully be able to check compression this weekend.

Re: 1987 Johnson J200TXCUC lost power

Well, I have some results from the compression check. I didn't warm motor thinking of preventing any additional damage. Should I have warmed motor for correct compression check? Here are the results from my check (cold) from top of motor to bottom/each side.

Starboard 47 psi, 53 psi and 45 psi.
Port side 58 psi, 27 psi and 59 psi.

What are your thoughts to warming engine and the results shown?
Thanks for your input.

Re: 1987 Johnson J200TXCUC lost power

bird33 said:

Well, I have some results from the compression check. I didn't warm motor thinking of preventing any additional damage. Should I have warmed motor for correct compression check? Here are the results from my check (cold) from top of motor to bottom/each side.
X
Starboard 47 psi, 53 psi and 45 psi.
Port side 58 psi, 27 psi and 59 psi.

What are your thoughts to warming engine and the results shown?
Thanks for your input.

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These seem ver low to me. Are you doing the test with all the plugs removed, with a fully charged battery, with the starter operating at max rpm, and with the throttle fully open? I doubt that a warm engine will bring your compression to almost twice your current readings.

Re: 1987 Johnson J200TXCUC lost power

reiddo1, I have fully charged the batteries and checked with volt meter before compression check. As for the plugs, they were all removed at same time. I did not put throttle in WOT position so I will re-check psi #'s again and re-post.

Thanks for info.

Re: 1987 Johnson J200TXCUC lost power

bird33 said:

reiddo1, I have fully charged the batteries and checked with volt meter before compression check. As for the plugs, they were all removed at same time. I did not put throttle in WOT position so I will re-check psi #'s again and re-post.

Thanks for info.

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If the starter is turning the engine over with sufficient energy, you should be getting around 100 psi on all cylinders with the lowest reading within 80 per cent of the highest reading. While throttle position and temperature will have some effect, I doubt that your readings will improve that much. Good luck with this....... Don

Re: 1987 Johnson J200TXCUC lost power

I just re-checked psi #'s with full WOT and same results. Obviously I have major issues and would like to repair if not too costly but doesn't look good from what has been mentioned previously. I'm not sure where to begin but will remove heads as mentioned. With low #'s in all cylinders as shown, could there be a possibility that the gauge is incorrect? It is a rental from an auto parts store. Just trying not to open motor up if something else can be tested before removing head(s). What are your thoughts? Ready for the next move. Any idea of rebuild cost? Thanks as always.

Re: 1987 Johnson J200TXCUC lost power

your middle port side cylinder being half of the others tells the story.

Re: 1987 Johnson J200TXCUC lost power

I would get a different gauge to check again to be certian, make sure the rubber grommet on the tester lead is well secured and not pinched and leaking air. You are either getting the wrong readings or your engine is toast.
When you crank the motor keep it cranking until the gauge is no longer going up once it stays in the same spot for 2-3 cranks thats the reading hopefully you didnt crank it long enough on each cylinder the first time.
Those kind of figures are way off the mark you should be seeing around 100PSI at the least.
If you get the same readings with a different gauge then i would be pulling the heads off to take a good look.

Re: 1987 Johnson J200TXCUC lost power

Thanks for info. I will get a different gauge to verify all #'s again, it can't hurt my situation. I am curious as to why all of the #'s are within the 5-10% (of each other) except for the port middle (27 psi) but not 90-100 psi. This must be an obvious indicator of terminal damage if the "new" gauge shows the same previous #'s when I check again....Will the engine core (block, heads, crank etc) be beyond trying to get rebuilt? Any thoughts? I want to re-power eventually but was hoping to do that this summer.

Re: 1987 Johnson J200TXCUC lost power

bird33 said:

Thanks for info. I will get a different gauge to verify all #'s again, it can't hurt my situation. I am curious as to why all of the #'s are within the 5-10% (of each other) except for the port middle (27 psi) but not 90-100 psi. This must be an obvious indicator of terminal damage if the "new" gauge shows the same previous #'s when I check again....Will the engine core (block, heads, crank etc) be beyond trying to get rebuilt? Any thoughts? I want to re-power eventually but was hoping to do that this summer.

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Although I highly doubt it, keep your fingers crossed that both port and starboard cylinder head gaskets are blown. That would be an inexpensive fix compared to a full engine tear down.

Re: 1987 Johnson J200TXCUC lost power

Well, I was able to get another compression tool and re-checked today with the following results WOT (cold) from top of motor to bottom/each side.

Starboard 93 psi, 100 psi and 98 psi.
Port side 106 psi, 75 psi and 100 psi.

I am pleased to see they are within the ranges mentioned above. I do see that the problem is on the middle cylinder on the port side (75 psi). I will pull the head on the port side to see the obvious damage. Pictures to come soon. Lets say that piston is toast, what is/are solutions to repairing? With the top cylinder being 106 psi, could something from this cylinder be causing such a higher psi reading or visa versa? Another thought is that I haven't de-carbed this motor since purchase (July 2012) and not sure if previous owner did either. Should I perform de-carb now or wait until pulling head? Trying not to damage motor if I crank it with low cylinder. Also, a carb rebuild (x6) was to come soon just for my own precautions. Kits are only @ $25/each and wont hurt to do.

Thanks again for input/thoughts.

Re: 1987 Johnson J200TXCUC lost power

See Post #20 for comments. Sorry but I posted pictures first.

Re: 1987 Johnson J200TXCUC lost power

I just pulled the head tonight in the dark so I will try to get daytime pictures asap. Here are the pictures to review. Any thoughts are appreciated. Post #18 will kinda described psi #'s. I am very surprised with the condition of the cylinder walls in the Port top and bottom, was not able to crank over the motor to inspect middle which is the one of concern. I did tap (finger) on all 3 cylinders and tried to wobble to see if any play and they all seem firm with very little play. It does look like the middle piston has a very small nick as you can hopefully see in the picture. Does it look like the head gasket was leaking? I have ordered a new OEM to install. What can I do next to check other options/ideas? Thanks