1960 mercury 700 wont start

[mgascon]

1960 Mercury 700 70 HP.<br />Previous owner said it ran 2 yrs ago.<br />New battery<br />New plugs<br />New ignition (key switch)<br />I am not 100% possitive I have it wired correctly or if the starter is bad or????<br />As I turn the key, the chokes slam shut but it never attempts to turn over. I would have thought it would at least try to turn.<br />It is NOT froze up. I can turn it over by pulling on the rope and it is a tough pull.<br /><br />I have tried to wire it differently but nothing.<br /><br />I should have an owners manual any day in the mail.<br />You guys have anything starting pointers for me?<br /><br />Thanks in advance.

 

[emckelvy]

Re: 1960 mercury 700 wont start

It's a Dockbuster (direct reversing) and what you'd normally think was the START position is actually the CHOKE. This motor has no gearshift, it reverses direction with a bi-directional starter in order to run in reverse!<br /><br />The starter button is located on the throttle lever itself. You must have the key to the ON position, then with the lever slightly to either the Forward or Reverse direction, push the starter button to start the motor. Note that there are limit switches which keep the starter motor from operating if the throttle lever is pushed too far to the Fwd or Rev direction.<br /><br />Here's a good site to start with, it has a wiring diagram for your motor, and sections for maint of the carbs, ign, etc.<br /><br /> http://www.maxrules.com/wireindex.html <br /><br />HTH...............ed

 

[mgascon]

Re: 1960 mercury 700 wont start

Thanks! I was trying to start it as I would my truck, by turning the key. I will try the button the second I get home.<br /><br />Another question....<br />With engine off (obviously), as I try to turn the prop, it turns the engine over no matter what position the gearshift handle is in. Is that normal or do I have more problems?

 

[merc_500]

Re: 1960 mercury 700 wont start

with the shift lever in the neutral position you should be able to turn the prop in both directions without turning the motor over. <br /><br />check the shift linkages and adjust as required.

 

[emckelvy]

Re: 1960 mercury 700 wont start

NO, this motor DOES NOT have a gearshift. It is DIRECT DRIVEN. It starts in gear for forward, and also starts in gear for reverse. Thus it is ALWAYS in gear no matter which way you turn the prop.<br /><br />That's the reason for the bi-directional starter. Let's say the motor is running in fwd. As you pull the lever back, you reduce the throttle setting and retard the timing. As you pull the lever back further, the motor stops. This was called the "Silent Neutral".<br /><br />As you further pull the lever back to the Reverse direction you shift the timing to the opposite direction and push the Start button on the control lever, starting the motor with reverse rotation and thus reverse gear.<br /><br />This was Karl Kiekhaefer's perverted solution to the problem of damaged shift clutches on higher-output motors and didn't last but a few years in production.<br /><br />Good motors if you keep them in tune. I had a Merc 700 Dockbuster on a little ski boat, what a sweet runner it was! Always started, belie-ing the Dockbuster name.<br /><br />Which, BTW was acquired when coming into the Dock and it didn't start back up in Reverse! WHAM! Another busted dock!!! lol.<br /><br />Have Fun with your Antique.............ed

 

[mgascon]

Re: 1960 mercury 700 wont start

The wiring diagram sent me the right direction. It wanted to turn over when pushing the button in the handle! I didn't get much farther than that due to how late it was.<br /><br />Back to the last post you made. So silent neutral means the engine is off? If I understand your posting, if I am in reverse, slow down then go to put it in forward, there is a "dead zone" in the middle? Same as forward to reverse.<br /><br />She is an antique! I think it will be a great conversation piece at a minimum. <br /><br />Thanks again for the help!<br />Mike

 

[mgascon]

Re: 1960 mercury 700 wont start

Good news! We have spark. The down side is that there is only spark in 3 of the 6 plugs. I pulled the distributor cap and there was some moisture. I dried it out and lightly sanded all of the contact points and on the rotors. I also sanded the thing in the middle. Still only spark in 1,2 and 6. Looking at the wiring of the distributor, it fires on every other prong (wrong term I know sorry about that). Now I am at anther road block.<br />As a reminder, all plugs are new.<br />Where should I go/test from here?<br />Thanks again.

 

[emckelvy]

Re: 1960 mercury 700 wont start

Odd, I thought one coil fires even cyl's and one fires odd. Maybe pull each coil wire, and see if you get spark out of each coil as you crank the engine. <br /><br />BTW, as an aside, while you're cranking this engine over it's been either on a flusher, in a barrel, or on the back of a boat in the water, yes? Otherwise, it's pretty hard on the impeller to be spun over dry. Even if you put it in a bucket which covered the entire lower unit with water it would be better than running dry.<br /><br />Lots of times, if you just run sandpaper over the points, it doesn't clean them up enough. Take the points completely out, and clean each contact to smooth (or as smooth as possible) metal and degrease them. I have good luck cleaning the points up with a whetstone, but you can use sandpaper on a flat surface, and a final polishing with Crocus Cloth.<br /><br />A preliminary points-gap setting of between .008" and .010" will probably be good enough to run the motor. However, if you do get it going, you need to delve into setting the dwell so it'll run more smoothly. Put a little moly grease or lubriplate on the points cam before you slap it together.<br /><br />If you are only getting spark from one coil, you may have a bad ballast resistor (the funny rectangular devices on the side of the block). There's one for each coil (nope, not true, they're in parallel - check the diagram, silly!!-ed 8/4) and you should have seen a diagram or picture of them at the Maxrules site. If you haven't found that section, click on the links to get to the Mercury Ign Tuning section, which has a wealth of info on how to set these ign's up.<br /><br />You can check the ballast resistor with a meter, to see if it's still good. If bad, you can probably just replace it with a suitable automotive external ballast resistor. The coils are pretty much standard car coils and you could replace a bad one with a coil that requires an external ballast.<br /><br />You could also have a bad condenser, so don't rule that out until you prove otherwise. I'd say most likely the points just aren't clean enough yet.<br /><br />Now, if you've got hot spark out of both coils, but no spark out of the distributor, you may have a bad rotor. As you've seen, the rotor handles 1/2 of the cylinders on one of its sections, and the other half on the 2nd part. If one part shorts to ground you lose spark for those cylinders.<br /><br />It's not much more complicated than that, just think of it as (2) 3-cylinder motors with one set of points, coil, and condenser each, and you'll have no tribble at all!!!!<br /><br />Good luck and watch out for the Docks!!!!........ed

 

[mgascon]

Re: 1960 mercury 700 wont start

I do have a garbage can of water for prob to sit in! Thanks for the reminder though. In fact, the can was not exactly centered and since you start it in gear, I darn near tore a hole in the (plastic) garbage can. I saw all of these floating plastic pieces and wondered what the heck it was. Then I realized. Anyway, back to my problem...<br /><br />I did check the coils. One is putting out significantly less than the other. I was not sure if they were supposed to put out the same amount or not. I dont remember the numbers now.<br />Are they supposed to put out the same amount?<br /><br />I will try your other ideas as well. I feel like I am so close!<br />I wish my manual would show up.

 

[emckelvy]

Re: 1960 mercury 700 wont start

Putting out, you mean like spark, yes? Both coils would have to have good blue spark for the motor to run well. <br /><br />I expect if you've got weak spark, one of the points is probably still dirty. It could be a bad coil, but it'd be easy enough to swap the existing ballast resistors and ign coils to eliminate that problem.<br /><br />Sounds like you're real close. The manual will help a lot!!! Have Fun!!.......ed

 

[mgascon]

Re: 1960 mercury 700 wont start

How do I remove the rotor?<br />I have the whole dist assembly removed but cant find a way to remove the rotor. Is it pressed on?<br />Once I get inside, what do I look for? <br /><br />I switched the wires on teh coils and am still not getting spark on the 3 plugs that were not sparking before. Still looking at points?<br /><br />Thanks

 

[mgascon]

Re: 1960 mercury 700 wont start

OK, I got the rotor off. Replaced the condensors and no spark to any plugs. I will go try again later but at this rate, she is going to the shop.

 

[emckelvy]

Re: 1960 mercury 700 wont start

Did you do the points? Replacing the condensers alone won't do the trick. You need to remove the points and mechanically clean them up to shiny metal, degrease, then set to .008-.010. It's a very Stone-Age setup and little really goes wrong with them, just dirty. Check it out carefully and give 'er another shot before you throw in the towel!!!

 

[mgascon]

Re: 1960 mercury 700 wont start

Is there a way to test the points?<br />I have spark on 1,4 and 5. When looking at the dist cap, that is every other one. Would this be from one set of points not being correct?<br /><br />Thanks

 

[emckelvy]

Re: 1960 mercury 700 wont start

Swap the two wires coming out of the distributor, if the problem switches to the other cylinders, it's probably the points. <br /><br />Check for spark out of each coil and if you have it, the rotor's Most Likely dead in one half. <br /><br />Also check for +12V at each coil with a meter, between the + terminal and the block (ground). If you're not getting it, you may have a problem with ballast resistors.<br /><br />Note that there are different firing orders on the cap, the timing/synchronizing diagram at the Maxrules site shows which one is for the 66 C.I. motor.

 

[mgascon]

Re: 1960 mercury 700 wont start

I am thinking it might be a coil. They should put out the same amount of juice right? We tested them before and it seems like they put out wildly different amounts. <br /><br />If a ballast resistor was bad, would it cause the coils to put out different amounts?

 

[emckelvy]

Re: 1960 mercury 700 wont start

The coils should spark equally. In looking at the wiring diagram, the ballast resistors are in parallel with each other, and there is a jumper across the (+) sides of the coils. So, what voltage one coil sees, so does the other.<br /><br />You can also swap the coils if you can't figure anything else to do. See if the problem follows. Revisit my post of 7/31 as it pretty much explains a bunch of stuff to do.<br /><br />Don't forget that you don't even need to be testing spark out of the distributor until you get good, hot spark out of both coils. You need to know if it's getting at least this far, as if there's no spark out of the coils, the cap and rotor don't matter.<br /><br />Getting back to the points, one set of points is working for sure. The brown and white wires coming out of the distributor are the points wires; one for each set of points.<br /><br />These 2 wires go to a terminal block on the side of the motor.<br /><br />If you swap these 2 wires, all you're doing is swapping which coil each set of points will fire. Therefore, if one set of points is good and one set bad, when you swap wires, the coil that is firing weakly should fire strong, and vice versa.<br /><br />If the problem stays with the same coil, it can't be the points or condenser causing the problem. It has to be a problem with the coil, or wiring.<br /><br />Take another look at the wiring diagram at the Maxrules site and you'll see how each points/coil setup is just a duplicate of the other.<br /><br />One other thing that I hadn't thought about, from looking at the diagram, is that you will get a full 12V to the coils when you engage either starter solenoid. If you'll notice, there is a jumper wire from each solenoid, to the (+) terminal on the coil. When the solenoid engages, power flows from the main battery wire straight to the coil, bypassing the ballast resistors. So, they aren’t even a concern when starting! <br /><br />This narrows the possibilites down to either a bad coil or bad points, time for more checking!!<br /><br />Let us know what you find.........ed

 

[mgascon]

Re: 1960 mercury 700 wont start

OK, I had some guys come over last night and we thought we had it down to a short. maybe not though. Here is what was done.<br /><br />New coil installed (front). The one I thought was bad. Same results.<br />With all wires hooked up, only get spark on 1/2 the plugs. If the wires from the coils are reversed, the other 3 plugs have spark. The same results happen when the white and brown wires going to the points are reversed on the blocks.<br />There is good continuity from the point(s) to the point that they screw to the block.<br />The ohms are the same on both coils (new and old).<br />Points were removed, cleaned, re gapped.<br /><br />Not sure if this helps but the balast resisters are very very warm. Should that be the case? Maybe a short?<br /><br />Thanks

 

[emckelvy]

Re: 1960 mercury 700 wont start

The ballast resistors would run on the warm side, they are just big coils of wire. If they're both warm, that's usually a good thing, it indicates they're both working.<br /><br />Let's see what you have now;<br /><br />I assume you're swapping the center ign wires off the coils, and not the other elect conns. So, you swap these wires and it changes what cylinders have spark. That still means you're only getting spark from one coil. To get spark to the other set of plugs, you have to have a good rotor since 1/2 of the spark goes thru the bottom wire's conn on the cap, and the other half of the spark goes thru the side terminal on the cap.<br /><br />There can't be much more controlling this than points/condenser/wiring.<br /><br />One thing you can do, to make sure both points are opening and closing, is to disconnect the brown & white distributor wires from the terminal block.<br /><br />Connect a meter to either wire, and the other meter lead to the distributor casing. When you rotate the distributor (you can just use the rope starter for this), you should see the meter reading change from Zero ohms (a direct short) when the points are closed, to a value much higher than Zero when the points open. You will see some resistance across the condenser, at least for a bit while the condenser charges.<br /><br />Repeat the above for the other wire. If both are acting the same, there should be nothing wrong with the points/condensers. But I suspect you have a bad (grounded) set of points and that's causing your problem.<br /><br />See if that helps...........ed

 

[mgascon]

Re: 1960 mercury 700 wont start

I am switching the coil wires right from the top of the coils. With both coil wires hooked up correctly, only spark on 3 plugs. I remove the coil wire from the back coil and the same plugs still fire. If I reverse the coil wires, the other 3 plugs have spark. This tells me only the front coil is good. Right? I bought a new coil, put it in and now only get spark from the back coil. What the? I removed both coil wires and spark came out of the top of the back coil but no spark came from the front. I put the old coil (front) back in, spark flies from both of them. Again, when I hook the wires up, I only get spark to the plugs from the front coil.<br />I dont suppose your heading to so washington any time soon are you?