OMC Cobra died at WOT - Help!

[Baylinercapri1987]

So I was fishing yesterday in the SD bay, engine was running good all morning until the end of a 15 min ride at near WOT. The engine did not over heat, or make noises really, It just stopped suddenly at near WOT and would not fire after that. I checked the compression and all are good at around 165-175 psi on a Cold engine. I checked spark and a good spark was present, checked for fuel and the carb sprayed when the throttle was depressed. Before this I changed the oil, changed spark plugs/cap/rotor/points and set the timing to 10* (was at 2* for some reason??). Any thoughts? I was thinking maybe the timing belt skipped??

 

[Don S]

Re: OMC Cobra died at WOT - Help!

What kind of engine is it? 4-6-or 8 cylinder, Ford, Chevy ??????

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Sorry 87 Ford 2.3L. I just checked the timing belt, it aligns with the timing 0 mark on crank, checked rotor position and it seemed to be pointing at #2, So I re aligned the distributer at #1. Tried to start and i get a few "pops" like its still out of time and wants to start.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Ok, Its a timing issue. I got it running by aligning the distributer to #1 on tdc. The timing belt is aligning right... But it seems the distributer is getting out of wack somehow...As i was timing it to 10* the thing started going down the timing grid and finally went below 0 and stalled out. Could this be from the points and condenser i just installed? I gapped them with a feeler gauge but did not set the dwell (no meter). Is this my problem or ????

Edit.. The point gap looks good...

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Any thoughts?

 

[Coors]

Re: OMC Cobra died at WOT - Help!

I don't know your engine, but something slipped; loose belt etc.
search for manuals in here.

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

Before this I changed the oil, changed spark plugs/cap/rotor/points and set the timing to 10* (was at 2* for some reason??).

The reason it was at 2 degrees was that changing the dwell effects the timing. I would definitely set the dwell with a dwell meter and not do it by gapping. You always need to recheck your timing after setting the points.

Did you check for spark at all the cylinders?

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

As i was timing it to 10* the thing started going down the timing grid and finally went below 0 and stalled out.

Can you explain what you mean here? Are you saying you set it at 10 degrees and then the timing changed all by itself? You are using a timing light right?

Do you know what the dwell spec is for your engine? Some engines are very picky about dwell. The reason is that too short of a dwell will not full charge the coil. Too long of a dwell will not allow the field in the coil to fully collapse. Both cases can effect the spark.

 

[Don S]

Re: OMC Cobra died at WOT - Help!

Sorry 87 Ford 2.3L. I just checked the timing belt, it aligns with the timing 0 mark on crank, checked rotor position and it seemed to be pointing at #2, So I re aligned the distributer at #1. Tried to start and i get a few "pops" like its still out of time and wants to start.

Try that test again now that you realigned the distributor the first time.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Can you explain what you mean here? Are you saying you set it at 10 degrees and then the timing changed all by itself? You are using a timing light right?

Do you know what the dwell spec is for your engine? Some engines are very picky about dwell. The reason is that too short of a dwell will not full charge the coil. Too long of a dwell will not allow the field in the coil to fully collapse. Both cases can effect the spark.

Yes, I was running the engine here at home after I set the distributer to #1 on TDC. I had a timing light on it, and got 10* but it started moving down on its own to below 0* tdc. and stalled soon after. I tried moving the dis. but it hit the alternator & had no room to time. I have 2 manuals, a seloc and a omc genuine. No dwell meter yet, I will get one tomorrow.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Try that test again now that you realigned the distributor the first time.

I did that test a few times, and I ended with that test, the roter was near #1 tdc after running and stalling it. Looks to me the belt is slipping or the auxiliary gears driving the distributor are binding up??

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

The reason it was at 2 degrees was that changing the dwell effects the timing. I would definitely set the dwell with a dwell meter and not do it by gapping. You always need to recheck your timing after setting the points.

Did you check for spark at all the cylinders?

Yes thats why I timed it (book said to after points job) The seloc book also said new points just need to be gapped and dwell meter is for used points, Going to get a meter tomorrow.

 

[a70eliminator]

Re: OMC Cobra died at WOT - Help!

What was your idle speed when you were looking at the 10 degrees advanced timing? If your RPM was up then mechanical advance built into the distributor could have been advancing the timing, you must check that timing at RPM's as low as possible to eliminate all centrifugal advance 600RPM's or less, without knowing the advance curve of your motor. Anyhow back to the issue at hand, I wouldn't think a timing issue would cause your motor to up and just die all at once without popping and backfiring and all sorts of bad thing happen when an engine jumps time, something tells me your problem is fuel related or loose wire connection somewhere in the ignition circuit.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

What was your idle speed when you were looking at the 10 degrees advanced timing? If your RPM was up then mechanical advance built into the distributor could have been advancing the timing, you must check that timing at RPM's as low as possible to eliminate all centrifugal advance 600RPM's or less, without knowing the advance curve of your motor. Anyhow back to the issue at hand, I wouldn't think a timing issue would cause your motor to up and just die all at once without popping and backfiring and all sorts of bad thing happen when an engine jumps time, something tells me your problem is fuel related or loose wire connection somewhere in the ignition circuit.

The boat would not start at all, I only started it when I got the roter to #1 on TDC. That makes me believe its timing related. And the way the timing just changed on its own, and could not maintain 10* timing. It was kinda low to mid between 500-800 rpms, it keep moving down so only seen it for a short period at 10*, at 10* the engine sounded good.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Try that test again now that you realigned the distributor the first time.

Ok did the test for you again, the roter is now not pointing at #1, more now at #2. I was looking at it advanced before...

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Just took the timing cover off, Every thing looks ok. The belt is tight, and the pulleys look good. The belt tensioner pulley has some belt build-up, and there was some small belt residual under it as well. Took the distributor out, gears look good.

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

Almost sounds like the mechanical advance may have a problem returning to its low rpm position. Maybe you rev it up and then you set the timing and after some vibration, the plate vibrates back to its low position.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

I Was not revving it, was trying to time it at idle.... And it just dropped timing when I was watching it with the gun. Going to inspect more parts tomorrow.

 

[Douglas Alderman]

Re: OMC Cobra died at WOT - Help!

Had the same problem with my '86 Bayliner. It turned out to be the coil

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Distributor gears look good, and the aux gears look good too. The belt looks intact and good but old. This has got me right now......