OMC Cobra died at WOT - Help!

[bruceb58]

Re: OMC Cobra died at WOT - Help!

Hard to tell from the picture about the condition. Can you manually make the weights move out and do they spring back to their "rest" position?

How much play is there in the distributor shaft itself? Any play caused by worn bushings will change your dwell and, therefore, change your timing. That is another reason you need a dwell meter. You can then see how much the dwell moves. It should be rock steady but will vary a lot if the distributor is worn. I keep mentioning this dwell meter but I don't hear you thinking about trying that yet.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Re: OMC Cobra died at WOT - Help!

Yes I can move the weights and they spring back into the "rest position" they look good to me....

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Could by chance it be a sensor of some sort? Does it have a timing sensor or knock sensor??

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

Could by chance it be a sensor of some sort? Does it have a timing sensor or knock sensor??

Not if its a points type ignition.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

[/quote] How much play is there in the distributor shaft itself? Any play caused by worn bushings will change your dwell and, therefore, change your timing. That is another reason you need a dwell meter. You can then see how much the dwell moves. It should be rock steady but will vary a lot if the distributor is worn. I keep mentioning this dwell meter but I don't hear you thinking about trying that yet.[/QUOTE]

There is play about a centimeter or two. Dwell meter tomorrow for sure! Just did not think it could shut the engine down like this, and it was running good after the tune up.

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

There is play about a centimeter or two. Dwell meter tomorrow for sure! Just did not think it could shut the engine down like this, and it was running good after the tune up.

2 centimeters? You mean 2 millimeters maybe? 2 milimeters is a lot of play. It is far greater than your point gap itself! With that much play, it makes it near impossible to set your dwell.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Sorry its about 3-4 mm of play.

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

That is A LOT of play. When you put the dwell meter on there, you are going to be surprised what you see...dwell will be all over the place when you rev the motor. Probably won't be anywhere near what you think it is.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Check it out...

http://s64.photobucket.com/albums/h169/Igofaster13/?action=view&current=008-7.flv

 

[bruceb58]

Re: OMC Cobra died at WOT - Help!

No..its sideways play that you should be checking. Not even sure what the play in that direction should be.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

I don't feel any side to side play... solid other then the play in the video.

 

[Don S]

Re: OMC Cobra died at WOT - Help!

The roll pin holding the gear on the end of the distributor shaft is probably sheared, but binding, which allows you to run the engine while it slowly turns till it won't run. You just keep chasing it.

 

[xltier]

Re: OMC Cobra died at WOT - Help!

thats not the play hes talking about.thats normal.yo need to take the top of the shaft where the rotor goes on and try to move it side to side.you are checking the clearance of the bushing where the shaft goes down thru the housing.if there is alot of play there the tension of the points will make it impossible to set the gap.you can hook up a dwell meter and just crank the engine with the key and the cap off.u can adjust the point dwell with a screwdriver while its cranking.that is a fool proof method.hth

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

The roll pin holding the gear on the end of the distributor shaft is probably sheared, but binding, which allows you to run the engine while it slowly turns till it won't run. You just keep chasing it.

It might be but I cant move it at all with my hands, all most looks like it has been binding and scratching up this mark... Is the mark on the shaft normal?

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

And one side of the pin area is mangled looking and the pin is basically missing. Check it.....

Missing pin??

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

I held the distributor in place and tried to turn the bottom gear, its loose I can turn it no problem..... it is binding.....Don S I think you may have it here!! Should I install new roll pins or get a whole new distributor?

 

[Don S]

Re: OMC Cobra died at WOT - Help!

The picture (in the link below) answers the question. The hole in the shaft isn't lined up with the hole in the gear, and part of the pin is missing.
Geee. wonder where the pieces went, and wonder what the cam gear looks like.

http://i64.photobucket.com/albums/h169/Igofaster13/029.jpg

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

The picture (in the link below) answers the question. The hole in the shaft isn't lined up with the hole in the gear, and part of the pin is missing.
Geee. wonder where the pieces went, and wonder what the cam gear looks like.

http://i64.photobucket.com/albums/h169/Igofaster13/029.jpg

The aux shaft that drives the distributor (not cam driven) looks to be in good condition, I took it out today and closely inspected it. I am thinking buy a new pin and install it, so there is a hole in the shaft for the pin to lock into? Time for a magnet drain-plug.

 

[Don S]

Re: OMC Cobra died at WOT - Help!

The aux shaft that drives the distributor (not cam driven) looks to be in good condition,

Yea, forgot what engine you had.

Yes, the roll pin that hold the gear in place goes all the way through, and it is slightly offset to one side, so you could find the hole on one side lined up and the other side is not lined up. Turn it half a turn and it will line up both sides.
Knock the old pin pieces out of the hole and get the PROPER pin to put back in.

 

[Baylinercapri1987]

Re: OMC Cobra died at WOT - Help!

Does Napa have good pins if i get the right size, or Should I get one from my Omc dealer? Thanks For the help again, everybody included.