testing a coil from a late 60's merc, How can I tell if it is any good?

[molsenice]

I have a 95hp '67 Mercury Outboard serial #2124524 I did a dumb thing, the Battery cables being older I mistakenly touched the terminals in reverse - the red initialy looked black). This was no long duration, just a tap and a zap, I saw a spark. Looking through other postings, I realize my mistake is going to cost $$$$. In testing the motor, I had no spark coming through the coil, but is this posibly a switch box problem or is their a way to test the coil to see if that is the problem. I was told at a local marina that it was most likly the coil, but a posting from aeronutt back in july of 2002 make me think it could be the switch box. Prior to this, the motor ran awesome, Thank you in advance

 

[Scali]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

rectifier will be fried

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

is there a way to test the recifier? It must be one of three things not allowing spark. If the rectifier is a posiblity, then thats one. If that is the problem, would that not allow spark through the coil? I am willing and obviously in need of a plan of action. What should I change out first? Rectifier - haven't looked for one, Coil? - not available - was told keep the faith - they are out there. Or should I change the switch box, these I understand can be purchased for around $320, which I deam cheap to solve my idiot manuver. Please advise and I really apreciate your time and help

 

[Scali]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

test it on the battery with a volt meter.<br />hook up probes with the motor off the when it's running, you'll see an increase in volts , then it's OK.<br />If it's charging rectifier is OK

 

[GaCracker]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Call me stupid, but I don't think you can fry a coil by reversing polarity.

 

[Scali]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

no but you'll without a doubt fry the rectifier

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Scali: First, thankyou for your input - once I get the motor running, I will test the rectifier, so I think it is safe to say my "no spark" situation is not the rectifier, brings back a memory of when I jump started an old Honda CB400f Bike, rectifier went bye - bye. GaCracker, thank you as well: anyone tring to help me is a HERO!!!, this is my Dads boat ( he gave it to me this year)and it has all my childhood memories - especialy the motor how it smells when starting, I was the kid who got to hook up the gas line and pump the ball, when I mentioned what I did (reversing the Battery)at Chic's Marina in Lake George, and mentioned I had no spark past the coil wire, to the distributer, they informed me I cooked the coil. I always believed that a coil was pretty tough and rarley went bad - but I have to start somewhere. So at this point it is looking like I will need a Rectifier, or a really long water proof extension cord for a battery charger, but first I need to get spark to the plugs so I can take Pop fishing on Eagle lake. I found a posting from a member "aeronut" from back in 2002, looks like I am going to need a switch box.

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Please pardon me for posting when I don't have direct experience and expertise with this motor, but I have to ask: does your 1967 motor have a switchbox? I looked at the parts list here:<br /> http://www.mercruiserparts.com/selectDocs.asp?doc_nbr=+39964 <br />As near as I can tell, this ignition system uses breaker points and a distributer rather than a CDI ignition. <br /><br />If you have a manual, it should provide the specifications for testing your coil and stator. If this system has points, you might look to see if they are clean and properly gapped before getting into more exotic possibilities. If you don't have a manual, I recommend the Mercury factory manual instead of any third-party options. Not cheap, but will pay for itself. Can be ordered at oldmercs.com and elsewhere, maybe here at iBoats also. Lots of parts for old motors at that site also. eBay can be a good source for hard to find items as well.<br /><br />I agree that you will likely have fried the rectifier. I have seen posts here and elsewhere about using an inexpensive Radio Shack replacement, no idea if that will work with yours or not.<br /><br />A careful examination of your wiring diagram would help to clarify the relationship between the charging system and the ignition system, and might shed light on whether the blown rectifier would affect spark or not:<br /> http://www.maxrules.com/wireindex.html <br /><br />Good luck and keep posting. There are some real experts here (I'm not one) who can help you get your memories running again. And take your dad fishing today, even if it's just from the shore!

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Hm..seems they changed the ignition sytem to solid state right about then. The ignition coil part number (332-2826) that you gave in your other post was superceded by part number 332-4895A7, although that shows as no longer available also. Perhaps this will help in runnning one down--maybe eBay?<br /><br />Also, oldmercs.com shows an "aftermarket switchbox and coil kit" (part number 332-2986K) $240 that looks like it might fit your motor, you should contact them to see if it will work, if you determine that is what you need. You can see it here:<br /> http://www.oldmercs.com/ignsys.html#78614A1 <br /> <br />Good luck!

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Motor Boater Bill - no pardon necessary - any insite is a lead I did not have - will take your advice since pop doesn't remember needing a manual and will get one, he bought the boat with the motor sometime arouond '76 and other than having the fuel line and stering cables changed out due to age, the motor has never needed any work and the motor and Boston Whaler are in mint condition (love the smell when the boat cover is removed). I was thinking switch box since I found a post as metioned before from "aeronut" and I just assumed - I know where that can lead. Guess I should count my blessings Thanks again

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Motor Boater Bill - THANK YOU the links you provided helped me figure out that the motor is definatly a 950SS (it has a switch box) the 950 looks like it had 2 coils and no switch box - mine has the one with a switch box. I have no idea what a CDI ignition is but this baby does have a distributor. and the 950SS wireing diagram looks most like what I have

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

CDI is capacitor discharge ignition. Basically, that is what you have in later motors after the old breaker points style of ignition that was in cars and everything else before electronic ignitions. So, you have solid state, or electronic, or CDI ignition, it's all the same. If in fact the problem is in your switchbox or coil, it seems like that aftermarket kit from oldmercs might be the thing. The kit is listed as replacing the switchbox that is listed for the 950SS. But for 240 bucks, it is worth figuring out if that is actually the problem first. Good luck!

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

thankyou, found a testing procedure to check the switchbox even though most posting tell me that is the target I need to aim at, will be ordering a switchbox and rectifier today - will let you know how I make out.

 

[Laotzu]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

It's probably too late if you already bought the switchbox, but you are heading down a dangerous path....buying parts if your not certain they need replacing. I think you would be better off buying a DVA meter so you can properly test the parts. Cost about $100 and you can use for life.<br /><br />My son works for GE and lives in Burnt Hills. He took us to a restaurant on Lake George that has the best Prime Rib in the world. Can't remmember the name, but the owner gives you full credit for your donation to the local Humane Society. So we ate for nix. You may know of the place.<br /><br />Jerry

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

There are some real experts here (I'm not one of them) who can help with the diagnosis on your engine. You should also check out John's Old Merc Q and A board:<br /> http://www.pfs-ware.com/kwast/mercboard/index.htm <br /><br />Let us know how it goes!

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Laotzu: parts are on the way, but fourtunatly I am pretty sure they are the problem, mainly from previous posts from others who have done what I did. The name of the restaurant I believe is Georges - and you can't find a better steak anywhere. Thanks for the suggestions to all, nice link, Motor Boater Bill apreciated your help, will keep you informed

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Here's an update fellas. Sit down, grab a cold one - the memories are RUNNING - started first crank, called pop and started it for him - I lost it, was a babblin fool WOW - I can't thank you all enough - if anyone is ever in the Glens Falls, Lake George area, the brew and steaks are on me. Scali - I have inlaws in Long Island, you being the closest, are the onlyone I could actually thank in person, unless Laotzu ever comes from Washinton! to visit. My email address is fdougher@gfsd.org. Tomorrow, I will clean the boat, change the lower unit oil and thank god again for all the wonderful helpful people who have helped a 40yr old kid get his memories running again. Motor Boater Bill and GaCracker - again THANK YOU!!!!!!

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

WOW--that's GREAT!!<br /><br />I know the feeling. Even though I have upgraded to a 1976 20 hp motor on my boat, I get a great deal of satisfaction from keeping Dad's 1962 9.8 running and in reserve--something I've only been able to do with help from this board and John's Old Merc board.<br /><br />I'm curious--did you replace just the switchbox or did you do the aftermarket switchbox/coil kit?<br /><br />Here's hoping you and your dad have lots of fishing ahead. My dad was here this weekend and although we didn't go out in the boat, we did wet a line together in my pond. Priceless!

 

[molsenice]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Motor Boater Bill: Changed out the Rectifier, knew no matter what, that was toasted. I got the aftermarket switchbox / coil setup. Simple enough to hook up, they mention it does not have the terminal for the origonal style tach's, but pop's boat never had one and since it was $100 cheapear, went with that. This also solved the question that started the hole thing off. I did have a question for the folks @ oldmerc's, the replacement part, had me clipping off the terminal rings and soldering on new plug pins - everything was pretty simple except no mention of the brown wire on the four post side, they called back - the brown was for the tach, which I do not have - tape it off. Nice folks! Now that my heart has returned to a somewhat normal beat, I'm wondering if I need to worry about the fact that they never mentioned where to hook up the Mercury switch. I know it is a safety - not hooking it up works for me, but I am not always going to be with Pop on the boat and a saftey switch is there for a reason.

 

[Motor Boater Bill]

Re: testing a coil from a late 60's merc, How can I tell if it is any good?

Good question about the Mercury switch. I'd suggest going back to the wiring diagram and seeing if you can sort it out from there. On the original wiring it seems like it is tied to the wires that run from the switchbox to the distributor, but with the aftermarket unit things may be set up differently. The folks at oldmercs (Grubbs) should be able to help with this since they sell the aftermarket kit. I've heard that some folks just leave the Mercury switch unhooked, but your point about safety makes sense. I think it's main purpose is to keep you from trimming the motor up out of the water while running, or from starting it while trimmed up out of the water. I guess it would also stop the motor if you flipped over, in which case the issue would be personal safety. Otherwise, it is simply protecting the motor from damage that would occur from running it out of water (pump impeller would be the first victim, followed by overheat and melt down).