points
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=2788
Printed Date: November-23-2024 at 8:00am
Topic: points
Posted By: JEFF KOSTIS
Subject: points
Date Posted: December-11-2005 at 7:25pm
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Does anyone have any experience with retrofit kits to electronic ignition on a OMC 225 in a 74 M17?? Richard from skiDim says that those kits use stick on magnets and have known to fall off. I get about 100 hrs of use between points. They are not a total pain, but not worrying about crap on the contacts is a nice thing. I also idle TONS with that boat and it chews the points up even quicker. It has Mallory single point ignition with the flat dist cap. They claim the prestolites are reliable and better to convert. Any opinions?? Stay W/points and know what Ive got, or try electronic and worry about a possible failure?? ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Replies:
Posted By: jimbo
Date Posted: December-12-2005 at 12:30pm
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I replaced the points in my 84 SN with an EI module a year and a half ago. There where some other problems at the time but the EI seems to be fine. The original distributor is a Prestolite.
If you've got some extra bucks and plan to keep the boat for a while, you might want to change out the whole distributor with an EI one, rather than mess with the aftermarket upgrade. Where's 79Nautique? He knows a lot about this stuff. |
Posted By: 79nautique
Date Posted: December-12-2005 at 1:39pm
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I don't know about glueing magnets to the base of a distributor. I guess if it's one then no big deal, other than cleanig it correctly so the magnet stays put but I don't thing I would use this type of conversion kit. Seems like it wouldn't last long and could do some damage in the long run.
Have you look at other suppliers that you wouldn't have to glue mangets in place or replacing the whole dist with a new elctronic version? Also are you running a balast resistor with your current set-up? or a coil with a built in resistor already? Seems awfull quick to be burning up points. It shouldn't make a differnce if idling alot vs. running. In fact it makes more since that they would last longer with extended idling, not as many operations/contacts for the same amount of time. For instance idle at 1000 rpm for an hour vs turning 4000 rpm for an hour you'll have 4 times the cycles or contacts for the hour or more use so to say. What engine do you have in the boat? If you can get a differnt style conversion kit I would use it instead or if the money isn't a problem get a electronic Dist. But it seems like there is too much voltage going to the points so if you stay with the points look at the ballast resistor/coil has a potential source for early failure of the points. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: JEFF KOSTIS
Date Posted: December-12-2005 at 7:52pm
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Its a 1974 OMC 225 307 chevy. Its all original and has the resistor. I wanted to keep the engine as original looking as possible. I dont care about inside the dist itself, but we have spent serious $ to try to make everything as original as possible.
I find that the idling causes the contacts to burn more because, if this makes sense, the points do have less open/close cycles like mentioned, but draw more current and flash more since you not collapsing the field of the coil as much. The resistor helps limit the current by reducing the voltage at idle to help keep the coil from burning out If the points are closed too long (like key on). Anyway, I was going by what skidim said for that dist, and recommened to stay w/points.  ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Posted By: 79nautique
Date Posted: December-13-2005 at 10:13am
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I would check with summit or jegs for an alternate brand of conversion kit. Something different from what Skidim sells. Any kit will work the marine part is in the base and cap and your not going to have to change any of that stuff for the conversion kit to work. Also the voltage is dropped all of the time not just at idle.After thinking about it a little more I can see where the points would see more use at idle speeds, since it would stay in contact a fraction longer due to the lower RPM's but it will not see any more or any less voltage across them. The points being in contact longer would discipate the coil more but all of that voltage goes to the rotor then to the plugs.
Do you change the capicator every time you change points? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: 79nautique
Date Posted: December-13-2005 at 10:20am
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look for a mallory 61004M or 61005M conversion kit ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: JEFF KOSTIS
Date Posted: December-13-2005 at 7:22pm
Yes as a rule I change the capacitor. I have about three of them hanging around, and have not been buying anymore. We have a BK Precision capacitor tester that will read from 1 pf to 10 mf. All I do now is check it, see if its stable and correct, and put it back in. I will check on conversions as you mentioned because it sure would be nice not to have to worry about them again. Thanks for the input 79!!  ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Posted By: 79nautique
Date Posted: December-14-2005 at 5:51am
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Not sure if the earlier numbers are right or not for what you have. You can try going to summitracing.com and they have a ton of different models to choose from. I punch in a 307 chevy and got a couple dozen p/n's for conversion kits. Good luck ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: JEFF KOSTIS
Date Posted: December-14-2005 at 7:44pm
Its a Mallory single point ignition with the flat cap. All of the wires come off the side of the cap.I can see if I can get the model off of it to make things easier. THANX ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Posted By: Jim_In_Houston
Date Posted: December-14-2005 at 11:18pm
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Jeff,
I went thru points suprisingling quick with my Mallory flat-top model YL distributor. With reluctance I replaced the points with a Pertronix conversion. Best money I have spent on the boat so far. With around .6 to 1 ohm resistance in your coil and .6 to 1.2 ohms in your ballast resistor the current flowing through your points, when closed, will be somewhere between 6 to 10 amps. This is a lot, imho, for a small contact set. I have no idea how the points last as long as they do. BTW, the Pertronix installation instructions advise that the ballast resistor be bypassed when installing the conversion so evidently their device can handle higher currents than a contact set, which should increase the spark voltage (unless the impedance of their device itself, is high enough to limit the current to a "normal" level). ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: JEFF KOSTIS
Date Posted: December-15-2005 at 6:36pm
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thanks Jim. Probably the resistor drop is in the kit already like you mentioned. Plus, you dont have to worry about closed points with the key just "on". One of these days, I will take a current probe on the scope and compare the current draw between idle and up to see what the current does. Thats nice to know your kit works good. I will get the model#. ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |