Omc 5.0 Pertronix bogging

[scooby14]

Hi, need some help with a bogging issue. 1988 Omc 5.0 Cobra, just purchased at the start of the season. Ran pretty good for the most part, but in the glove box was an uninstalled Pertronix Igition kit, so I figured I'd throw it in, along w/ a new cap and rotor. Starts and idles ok, but when you give er some gas it bogs. Will stumble along till on plane and then does ok. Not spectacular but just ok. RPM's wont go much over 3000 WOT. I've put the points back in and it runs fine. Done this a couple times while experimenting with timing (and idle adjustment as it initially had a hard time running at all)and i like the starting and idling of the pertronix over the points, but just need to work the acceleration problem out. I saw a previous post that talked about changing the timing advance mechanism when doing the conversion, but it didn't go into detail, and the kit didn't have any of that in it. Any thoughts will be greatly appreciated.

 

[Boomyal]

Re: Omc 5.0 Pertronix bogging

You are not clear on when you had the problem in relation to uninstalling the Pertronix. At most the installation of the Pertronix would require that you recheck/reset the timing to factory specs for your motor. Wires and carburetor have to all be in order as well.

 

[Dunaruna]

Re: Omc 5.0 Pertronix bogging

Check me if I'm wrong but doesn't the ballast resistor need to be bypassed when using the pertronix?

 

[Boomyal]

Re: Omc 5.0 Pertronix bogging

Originally posted by Dunaruna:<br /> Check me if I'm wrong but doesn't the ballast resistor need to be bypassed when using the pertronix?

Correctamundo!

 

[Dunaruna]

Re: Omc 5.0 Pertronix bogging

O/K, then maybe scooby needs to do a voltage test on the coil - might not be getting enough juice.

 

[Grayhorse]

Re: Omc 5.0 Pertronix bogging

Just installed Pertonix ignitor conversions on my twin 140's, and it clearly states in the directions to leave things as they are. If you have a ballast resistor, keep it. If you don't have a ballast resistor, don't add one. Just make sure you have 3 ohms of resistance and it should work fine. There is a trouble-shooting guide in the instructions, which I have at home. I'll check them out tonight, and forward any revelations.

 

[rbezdon]

Re: Omc 5.0 Pertronix bogging

Yes, I have an 88 OMC 5.0 also and you only bypass the ballast resistor if you change the coil to the one rated for full battery volts. For the module it has a seperate wire which connects to the ignition controlled +12. The problem is most likely that the Pertronix module is NOT compatible with the stock ESA. Either you have top make the circuit mods recommended by Pertronix (see their web sire) which involves building a small cheap circuit but making it weather proof etc or replacing the ESA with the CDI/Rapair 123-9898-P (cost between 57 and 85 depending where you find it on the internet).

 

[scooby14]

Re: Omc 5.0 Pertronix bogging

Thanks for the replies. In response, when I take the petronix stuff out, it runs normal again, so I'm certain that something is just not right with the install, or possibly with the module itself. I forgot to mention that my kit didn't have the instructions with it, so also no troubleshooting help. Yes I did the ESA fix that was required. I might have to look into the ballast resistor though. My motor also has a Pertronix coil that was alrady there when I bought it, so maybe that has something to do with it.

 

[rbezdon]

Re: Omc 5.0 Pertronix bogging

You should look into this carefully, some of the Pertronix coils were not good for running with points. The 1.5 ohm or less are rated for full battery voltage with the module but the low resistance and full bettery voltage will cause points to degrade quickly. Make sure you have the right parts matched up or I think you will not be satisfied with the results either way. By the way, not all the Pertronix coils are like this. They also make the 3 ohm OEM eplacement coil which still needs the ballast resistor. Just get the part numbers off of the parts and check with Pretronix customer support and find the right combination to have the system operate properly, point or module.

 

[Dunaruna]

Re: Omc 5.0 Pertronix bogging

Does it say on the box whether it's a series '1' or '11' (two, not eleven)?

 

[scooby14]

Re: Omc 5.0 Pertronix bogging

Its a series 1.

 

[Richard Petersen]

Re: Omc 5.0 Pertronix bogging

Pertronix ignitions are known to be erratic in some of their models. Requiring constant factory bits and pieces till the owner gets tired of that life. Leave in what works AND can be repaired anytime by anybody.

 

[rbezdon]

Re: Omc 5.0 Pertronix bogging

Just make sure you have the Pretronix coil that is compatible with the points and the ballast resistor or you'll have short point life or hard starting if thebattery gets a little low.

 

[scooby14]

Re: Omc 5.0 Pertronix bogging

Ok, just an update. I did some further checking and found that the # 4 cylinder is not getting a spark. Plug and wire are both ok, so I guess it is defective part from pertonix. I guess I will be giving them a call. Thanks for your responses.

 

[Dunaruna]

Re: Omc 5.0 Pertronix bogging

Originally posted by scooby14:<br /> I did some further checking and found that the # 4 cylinder is not getting a spark. Plug and wire are both ok, so I guess it is defective part from pertonix.

No. The pertronix module doesn't know (or care) that you have a V8 or 6cyl of 4 cyl, that's the job of the distrubutor cap and hall effect sensor.<br /><br />Did you check the spark plug lead on another cyl? Could also be crud inside the cap tower for #4.

 

[scooby14]

Re: Omc 5.0 Pertronix bogging

Definitely think its the pertronix, brand new cap and rotor were installed a couple months ago, and as I said, its runs fine with the points. I'm thinking its a problem with the magnets. When i was originally installing the module, the plastic parts came apart, and 3 of the eight magnets fell out. Managed to get them all back in, but i'm wondering if its possible that one of them is in backwards, if that would make a difference.

 

[rbezdon]

Re: Omc 5.0 Pertronix bogging

It is almost certainly the fault of the magnets and the hall sensor. I am not sure of the magnets are reversable but I am sure Pertronix can tell you.

 

[olbuddyjack]

Re: Omc 5.0 Pertronix bogging

scooby,<br />Pull the reluctor off the points cam and reindex it about 90 deg. on the cam. If its the reluctor the miss should go to a different cylinder. I've never heard of those things coming apart but I guess they do.<br /><br />We just took a boat trip up your way last week. Stayed at Fox Chapel a few nites and on the Beaver one. Had a great time!

 

[scooby14]

Re: Omc 5.0 Pertronix bogging

Ok, problem solved, (almost). Spoke to tech at pertronix, he confirmed that a magnet may be reversed. Just pulled out the module and tested with another magnet, 7 are pulling, one is pushing. So as soon as I reverse that all should be well. (except for adjusting the idle and timing again, because I have them way off (compensating for that missing spark). Anyways, wish I'd realized this sooner in the season, but oh well. Thanks again.

 

[Dunaruna]

Re: Omc 5.0 Pertronix bogging

Originally posted by scooby14:<br /> When i was originally installing the module, the plastic parts came apart, and 3 of the eight magnets fell out.

That might have been a handy bit of information to tell us FIRST.