omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

I have a 1988 buccanneer deckboat with the omc 5.0 and cobra outdrive. I upgraded the ignition system from the factory points distributor to a hei distributor. now i tried to run the boat two weekends ago and the interuptor switch isnt working, I didnt change anything with the switch and i didnt mess with it. Any ideas ? I have the manual and i know there is a section for testing the switches so I guess that is my weekend project. Any help would be appreciated !

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Ok I read some other omc shift problem posts on the forum and is it possible I went with the wrong components ? I just installed small block chevy parts... was I wrong to do so ? I am farely new to boats..And to clarify a little about the switch, it does nothing when pushed with the engine running fom what ive read the motor should stumble. right ?

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Jd. What ignition did you buy? I did mine recently and overlooked a step in very detailed directions offered here. Everything that you put in it needs to be marine rated as far as things that create a spark.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

You need to install a marine distributor. If you didn't, you need to pull your distributor and start over.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

I did not install a marine distributor. I went with a procomp hei set up....... I will get on ebay and get a marine dist coming. is there a brand i should center my search around? Can you tell me the differences in a "marine" distributor so that i can educate myself on the topic ? Im curious to know the differences...What about the coil ? Should that be marine as well ? Thanks for the help.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-140.html

Of course, check if it is for your application before ordering....

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

You need a kit compatible with the esa. Otherwise you will burn out the pickup coil in the electronic ignition module. Make sure you use marine ignition components. They are made to work in an enclosed bilge without blowing you out of your boat. I believe pertronix has a do it yourself conversion kit for the esa. The easiest fix is to return to the old points. They are high maintenence, but simply reliable.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

If you go with the Delco Voyager in mzahn's link you can change your shift switch to a Mercruiser type set up and it will connect directly to the delco voyager. You won't use the ESA anymore.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Thanks for the help.....I ordered the distributor kit that MZAHN posted the link about. The lady told me the kit has everything i need to convert my setup over except for the interuptor switch. Anybody have a part number and a website that I could order the correct switch from ?

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

You can use your existing switches. You just need to do a little rewiring to apply 12V to the interrupt input on the distributor.

Here are threads where DonS describes the wiring for the distributor
http://forums.iboats.com/showthread.php?t=287471
http://forums.iboats.com/showthread.php?t=489940

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Ok I recieved the distributor kit today and started right in on the installation. Placed the motor at tdc on the number one cylinder and removed my old hei distributor and coil. Continued by attempting to install the new marine distributor but I could not get it to drop in when pointing to the number one cylinder and I dont know why? I also dont know how important that it does ? At best I could get it to drop in at around seven o'clock where number one cylinder would be around eleven o'clock. So i just placed the number one wire at that point and ran around with the firing order. also mounted the coil and hooked up the gray (tach) and the purple (12v) wires, plus plugged the main wiring harness into the coil and then to the distrubutor. Thw directions say to start and warm up at 6 to 8 hundred rpm to set initial timing but my motor never started ? Just cranked and cranked. It should have started at this point in the install right ?

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Jd 1978 said:

Ok I recieved the distributor kit today and started right in on the installation. Placed the motor at tdc on the number one cylinder and removed my old hei distributor and coil. Continued by attempting to install the new marine distributor but I could not get it to drop in when pointing to the number one cylinder and I dont know why? I also dont know how important that it does ? At best I could get it to drop in at around seven o'clock where number one cylinder would be around eleven o'clock. So i just placed the number one wire at that point and ran around with the firing order. also mounted the coil and hooked up the gray (tach) and the purple (12v) wires, plus plugged the main wiring harness into the coil and then to the distrubutor. Thw directions say to start and warm up at 6 to 8 hundred rpm to set initial timing but my motor never started ? Just cranked and cranked. It should have started at this point in the install right ?

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Are you sure you have #1 at TDC on the compression stroke and the rotor contact at #1 on the dist cap? I'd check again and do it right. You won't be happy later if you don't.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Im not sure mzahn, I'm pretty sure i had the piston up on tdc cause my old rotor was pointing pretty much at the number one cylinder when i pulled it off. I turned the motor over several times by hand with the old distributor cap off to make sure the piston was up. So my plan is to keep messing with it until it gets closer I guess. Haven't had a chance to start on the interuptor side of it all, Im sure I will have some questions as soon as I get to that part of it....

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Not familiar with this particular motor, but on a Chevrolet, if you look in to the hole the distributor fits in to, you will see the the oil pump shaft sticking up, it has to be in the right position for the distributor to drop in at the location you want. otherwise, it just hits it, and sits on top and will not drop all the way down.. if the 5.0 is the same, this could be your issue

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

I would first make sure the distributor is actually giving out a spark by pulling a spark plug wire and holding it close the the engine block. If that works, you can worry about the timing.

You can actually check your timing with a timing light by just cranking the engine if you want to see if you are close.

You will have to read your directions on how to set the distributor in base timing mode once you get it running and need to set the timing accurately.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Jd 1978 said:

Im not sure mzahn, I'm pretty sure i had the piston up on tdc cause my old rotor was pointing pretty much at the number one cylinder when i pulled it off. I turned the motor over several times by hand with the old distributor cap off to make sure the piston was up. So my plan is to keep messing with it until it gets closer I guess. Haven't had a chance to start on the interuptor side of it all, Im sure I will have some questions as soon as I get to that part of it....

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You do realize there are two periods where the engine will be at TDC during a normal 4 stroke combustion cycle, right? The first TDC is at the end of the compression cycle right before the ignition cycle. The second TDC is at the exhaust cycle. When you set up the engine for #1 TDC to drop the distributor, you want the engine on compression TDC.

If you are brave, you can sick the tip of your finger loosely in the #1 spark plug hole, and feel for the spinning engine to push air out past your finger. At that point you line up your balancer with the 0? mark, and drop your distributor. If sticking you finger in the hole gives you the heee-be jeee-bees. You could also pull the valve cover for the odd bank of cylinders, and spin the engine over while watching your rockers go though their motions. You would be looking for the #1 intake rocker to open and close the valve, and at that point line up the balancer to 0? TDC.

As far as issues with dropping your distributor, as Reinell said, the oil pump shaft needs to be properly aligned with the distributor shaft. If the distributor refuses to fully drop, you need to look down in the distributor hole, and you will see a slotted shaft at the bottom (this is the oil pump drive shaft). You simply take a long slotted screw driver, and spin that shaft by hand until it will allow you to drop the distributor with the desired rotor position for #1 cylinder. It isn't etched in stone that #1 needs to be located at a certain point on the distributor. Just for the sake of simplicity, it is usually recommended that you line up the rotor pointing at #1 cylinder with #1 cylinder at compression TDC

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

I never knew you could adjust the oil pump shaft ! One quick turn on that dude and I am ready to go ! My rotor now points to the number one and the engine fires right up! thanks to all that replied! We got some bad weather coming in this weekend so I wont be able to get back installing the distributor kit until the middle of next week..

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Congrats...progress feels good.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Anybody have any info on the timing tab? The numbers on mine are gone and i had a cheat sheet that I got off a boat at the used boat place when I first changed distributors, but now I cant find that paper. I also cant find any info online. Im pretty sure there are pics here on iboats but all the pics i have seen all have red x on them and wont let me open them.

Re: omc cobra 5.0 interuptor switch doesnt work after upgrading ignition ....

Jd 1978 said:

Anybody have any info on the timing tab? The numbers on mine are gone and i had a cheat sheet that I got off a boat at the used boat place when I first changed distributors, but now I cant find that paper. I also cant find any info online. Im pretty sure there are pics here on iboats but all the pics i have seen all have red x on them and wont let me open them.

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Any different slot that may be 0 degrees? Not sure if this is similar.