1980 Mercury 40 hp Key switch?

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

I would start testing engine ignition at this point start by checking for any cracked wiring esspecially at the flywheel. Poping it off to do an inspection for broken grounds etc afterwards. i I would not rule out the CDI but usually if it is bad the main capacitor will through fire to a few cylinders. You can test that theory buy testing all the plug wires and not just one wire as that may be the bad sector. If you have fire on any plug I would not think it,s the stator It was mantioned earlier that you have a magnito on you engine if this is the case it may provide spark to some plugs and not to others. You need to confirm if it has a stator or magnito

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

It is a stator. I had it off to repair the wires and it looked OK? as in no broken wires...

Neither cylinder has fire.

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

your going to have to get the tests for the stator and trigger to determine if there are within specs. Having no spark at all can be any of them the stator the trigger or the cdi. At this point there is no other way I can think of as there is no spark to determine without testing which part it may be. Like I said usually as my older 40 HP did the switchbox only lost one cylinder when it went bad. This does not mean the main capacitor didn,t blow and render it totally dead though. This would point me to the stator. The triger on my 40 took current from the stator and the hub then sent the signal to the switchbox to fire one cylinder and then the switchbox sent the other signal if i,m correct in that assumption. Being you already repaired the stator as I know they tend to wear at the block as there to close to it and wear in time makes me think this time they may have grounded or shorted at your repair. The delema here is if it shorted it could blow the main capacitor in the CDI so back to suare 1. Testing must be done as parts are expensive and without testing it has just become a guessing game. Maybe someone can point you to the online manual to get the testing proceedure for that particular engine. Not saying you need it but here is a used stator on ebay, My 40 was a 1979 yours an 80 this should work. if needed http://www.ebay.com/itm/This-is-a-U..._Accessories_Gear&hash=item35c3b9eaa4&vxp=mtr This one is in better shape http://www.ebay.com/itm/398-5255-St...ccessories_Gear&hash=item53f19f5721&vxp=mtras for the switchbox I sold one a few months ago in this cond from my 40 for 85.00 there not cheap. Maybe you can use the numbers off the add to search around again not saying you need it but it,s here if you do http://www.ebay.com/itm/Mercury-Out..._Accessories_Gear&hash=item1e765d15f4&vxp=mtr This engine was Mine View attachment 179768 I went through 3 stators on it. View attachment 179769

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

I just want to confirm you removed the right wire to test for spark from the teminal and it is an orange wire not black and yellow Mine was located cetner of this terminal and goes to the tilt kill switch as well View attachment 179775 Older models and newer madles have different color kill wire to the terminal. disconnect it and ty again. Terminal color was red blue (orange Kill wire) white then browm I think but orange was in the middle

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

Yes, The center wire is Orange (diagrams call it Salmon) and the other wire on that terminal is Black/Yellow. I checked this wire and with the key off it makes a ground but not if the key is on. Anyhow yes i took the wire off and no spark.


I'm not sure if the boat ran I'd want to be out on the lake with the stator that was on it so I went ahead and bought the $100 one that was on Ebay. Funny you posted those 2 as I already had them saved to my favorites.

It should arrive Saturday or Monday and we'll see if it was the problem.

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

Good luck and make sure you tape the wire good at the stator as it has some pressure wear already.and file a bit at the block or bracket to give it a tad more room to flex thats what I did and it should be fine.

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

OK I got the new stator and it still wont start. I did use an Ohm tester on it and the old one before I put it on and the readings were the same.

Wen removing the flywheel I sprayed some penetrating oil on the keyway of the Crankshaft. This ran down to the trigger and I know the trigger is oily, will that keep the trigger from firing?

I took the rectifier off and tested it and it's good. and have changed out the cdi box and the stater

 

[Lone Duck]

Re: 1980 Mercury 40 hp Key switch?

You have a magneto ignition system which generates it's own power to provide spark to the plugs. Although the ignition switch may prevent the engine from starting, it is not for the reasons you think. A magneto system does not have a 12 volt input to it so there is no 12 volt line in the RUN position. The ignition switch has two "M" terminals on it that are connected to kill the engine (OFF position) or open to allow the engine to run (RUN position). "A" is accessory terminal which powers the gauges. "S" is the starter solenoid connection (START position). "B" is the battery connection via the engine harness. "C" is the push to choke connection.

Ok! Lets isolate things a little. Disconnect cable from control box at the engine. Jump the solenoid and turn the engine over and check for spark.( be careful it may start.) If it starts or has spark, your problem is in the control box or circuits going to it. (may be the neutral switch) If no spark, your problem is at the engine. Have engine in down position,may have a tilt kill switch

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

I would at this point disconnect the overboard switch or first unplug the harness from the engine to eliminate the boat from the engine. then check for spark. With a new stator a new switchbox trigger rarely goes bad but not likely I would use just the engine disconnected from the baot and narrow the problem daon using only the engine componants to fire the engine. If you get spark the problem lies in the harness the key switch throttle or overboard switch JMO I,m going on my test run afer rebuild in the am try as stated use only the engine to find the problem first

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

I guess I'll try unhooking the harness. I havent jumped a starter in years remind me what terminals to jump.

If the Blue and yellow kill wire is removed from the Salmon kill wire at the pack how can the "controlls" be the problem? Am I missing something? I just don;t understand how that will help but it is a simple test and I'm running out of other ideas so I'll try it in the morning.

I'm also going to clean up the trigger and dry it off

Thanks again guys!!!

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

Jump the small yellow wire with the red stripe on the solenoid to the positive battery feed side thtis will engage the solenoid to make contact with the starter wire and turn the starter. Be sure you have a good full charged battery. A weak battery may not be enough to give a strong spark and thats what you need as well as runing the timing light to check for spark. Be careful it will start without the harness connected.

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

I took the trigger out to clean things up and noticed it doesn't have the spring? Could this be my problem?

This has a pretty good pic of the spring i'm talking about.This Is A Used 1979 40 HP Mercury Trigger Assembly Part 4731A6 | eBay

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

You should have the spring and the nylon pin that goes inside the spring I sold a trigger about a month ago for a 1979 40 HP. I lost the nylon pin to keep the srpring rigid and use a piece of cut copper wire (Thick 20 amP) in it,s place. The trigger might be somewhat affected without it but I don,t think it would be enough to stop all spark. Then again it,s ridint the hub and may have worn through to the pick up and then yes it would be shot. The spring keeps tention on the trigger keeping it from rubbing and wearing it as i described above.

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

Ok I still have no fire in either cylinder. I unhiiked the mercuer switch and left it off. I surned it over without the wiring harness and nothing

Let's start over what should I test first

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

The trigger cannot rub the flywheel hub If there is no signal from the trigger there will be no signal sent to the switchbox.Therefore no spark. You have a replacement stator due to wiring issues which you say reads good. You also state you swapped out the switcbox as well. You have disconnectee the harness from the motor eliminating the key throttle etc from interference with the electronics of the engine. It,s not likely both coils ar bad. And also not likely both plugs are bad. You hopefully checked all grounds are hooked up There is one I had hooked to my rectifier screw to ground that if it wasn,t hooked up then I got no fire View attachment 180384 The only other thing I can think of is the trigger is NG or the missing spring is the cause of the malfunction. Hope this helps

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

Let me post a few pics maby someone will see something I'm missing.

 

[hi salenity]

Re: 1980 Mercury 40 hp Key switch?

The trigger cannot rub the flywheel hub If there is no signal from the trigger there will be no signal sent to the switchbox.Therefore no spark. You have a replacement stator due to wiring issues which you say reads good. You also state you swapped out the switcbox as well. You have disconnectee the harness from the motor eliminating the key throttle etc from interference with the electronics of the engine. It,s not likely both coils ar bad. And also not likely both plugs are bad. You hopefully checked all grounds are hooked up There is one I had hooked to my rectifier screw to ground that if it wasn,t hooked up then I got no fire View attachment 180384 The only other thing I can think of is the trigger is NG or the missing spring is the cause of the malfunction. Hope this helps

The trigger doesn't rub the flyweel it actually has a lot of clearance (what does it actually pick up on?) The stater and switchbox were off running motors but If you can give me better directions ... Ill test them again.
I did test the Rectifier and I'm pretty confident it's good.
I unhooked the harness and still no fire on either Cylinder.
The wire you were talking about is grounded to the rectifier

 

[Lone Duck]

Re: 1980 Mercury 40 hp Key switch?

Let me post a few pics maby someone will see something I'm missing.

(1) clean up all your contacts an screws. (2) The black wire on same terminal as orange where does black wire go? (3)Did you sand inside of flywheel? If not sure looks like rub marks there , thats a no no

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

The seperate black wire to the orange on the switchbox should be the tilt kill switch not the ground for the harness View attachment 180418 . The ground from the harness should be hookd to one of the switchbox hold down screws. View attachment 180417. The flywheel shows wear indicating rubbing against the flywheel that would blow the switchbox View attachment 180416 Bad bearing more than likely. Question Are any of the hold down screws that secure the stator striped? The stator must be securely held in place or as I described by your picture it is rubbing the flywheel and probably killing the switchboxes. It needs to be corrected or it will continue to blow more switchboxes. All you would have to do is change the upper end capand or bearing. That is fairly cheap on ebay. Note the upper bearing will come out with the upper end cap. I changed my upper bearing which also may be the cause of the rubbing marks on the flywheel. The seal will have to be redone as well JMO I hate to be the barrer of bad news but I,m 99% sure scraped one a week ago. EDIT I have to put the breaks on here there is obviously internal damage that lead to the condition that caused this situation of the flywheel rubbing the startor see next post

 

[Maxz695]

Re: 1980 Mercury 40 hp Key switch?

Water intrusion through the lower end cap and or the exhaust baffle causes a lack of lubrication condition which wears down the bearings. This includes wrist pin cranckshaft to connecting rods the reed blocks becoming mushroomed upper and lower crank bearings worn leaking seals. Missfiring coughing etc poor idol knocking are all signs of this condition. Due to extreem play at the upper bearing the flywheel appearently has enough play to rub the flywheel and burn out the switchbox. My suggestion at the moment would be to test the play in the crankshaft at the top and see how much it travels from side to side. Hopfully with alot of luck the upper bearing is just worn. Thats alot of wishfull thinking but it could be the case. Find out why the wear of the paint on the flywheel happened and start to do inspections to correct the condition. It is not a hopeless case but could turn into an expesive and time consuming bout. Get back to me with your findings I,m tired and done for the evening. I,ll check on this in the AM and afternoon.