40HP Big Twin will not start

[jchrans]

I’ll try not to make this too long, but here goes: Evinrude 40HP Big Twin 1970 Model #40052A, Serial #E01672. Put in new premium gear oil and new Champion J4C plugs. Compression was 105 on both cylinders, telltale showed good water flow. <br /><br />I took it out (it is on a 14’ MFG Carefree 1970 boat) on local river and it ran super. After having it out for a couple of hours cruising around going all out sometimes, and crawling sometimes, I wound up crawling for about 20 minutes when I decided to anchor up. I put it in neutral, and it ran rough and conked out. When I tried to start it, it would crank strong, but not fire. Gas was getting at least as far as the carb. A nice person on a waverunner towed us back to the dock.<br /><br />When I got home, I checked the plugs, one was oily and one looked dry and burnt. I tried to check if it was getting spark, but I don’t know if I was doing it right. I took the boots off the plugs and put them near the engine while it was cranking … nothing. I cleaned the plugs and put them back in, still nothing.<br /><br />After many attempts to start it, it suddenly didn’t do anything when I turned the key. I then traced to what point the current from the battery was going and found that it was not going through the solenoid when I turned the key switch. Tested the starter by jumping it to the battery and it worked fine. I then replaced the solenoid with one I had from a previous event, but it just made a clicking noise and eventually made no noise at all. I don’t know if that was any good or not, so I have ordered a new one, which I should have by Thursday (tomorrow). <br /><br />Then, I wanted to test compression, so I attempted to do it by jumping the starter to the battery … first try the starter cranked strong, however on subsequent tries it slowed considerably (enough that the bendix would not engage the flywheel). Therefore, I then hooked up an alternate source of power (12V/15AMP start off a battery charger), and the motor would crank … but only without any spark plugs in it. When I put one or the other or both in, the bendix would engage the flywheel, but would only moaningly turn it.<br /><br />So, what do I do next? <br />

 

[Paul Moir]

Re: 40HP Big Twin will not start

First thing is to charge up your battery and try jumping it to the starter again. The battery charger isn't nearly enough and it sounds like your battery is worn down. Then go for that compression test.<br /><br />What exactly do you mean by the looks of those plugs? Ideally you'll be seeing a tan insulator that appears damp with oil. Were either of these super clean, dead white, covered in soot, or what? Which one was which? Top or bottom?<br /><br />When you were trying to get spark, did you have the keyswitch in the 'Run' position? Try disconnecting the two black wires that originate up underneath the flywheel, tape them off (seperately) and see if spark returns.<br /><br />Do you have a multimeter? Digital/Analog? Brand name or model number would be helpful if it's convinient.

 

[CATransplant]

Re: 40HP Big Twin will not start

OK. First, charge your battery fully. It sounds to me like a dead, or bad battery. Until you get the engine to crank properly, you'll be out of luck.<br /><br />Next, to the spark. You won't get a spark if you hold the boot near the engine block at all. First step is to put a good plug in the boot and...using a WELL_INSULATED pair of pliers, hold the plug's threads on the block and look for spark while you crank the engine.<br /><br />If you get a spark that way, OK. It should be a nice fat bright spark. Put a new pair of plugs into the outboard. Not just cleaned ones, but new ones, and try starting up again.<br /><br />If you don't have a spark at all, then it's another problem. You'll need a manual to troubleshoot the problem. Follow the troubleshooting step by step.

 

[CATransplant]

Re: 40HP Big Twin will not start

Your outboard still uses the old 2-coil magneto system. If no spark after doing what I described above, take a look at the two black wires that come from under the flywheel. One goes to a vacuum cutoff switch on the starboard side of the engine. The other goes to the wiring harness on the side of the engine. Trace the wires, looking for any bare spots that might be touching metal. If none, disconnect both wires and try the spark test again. There should be a knife-style disconnect connector on the one going to the wiring harness. The other one, you can disconnect from the safety switch.<br /><br />If still no spark, then it's going to be time to pull the flywheel and find out what's not working. At that point, you're going to need a manual for sure. It's not a job that you should take on without one.<br /><br />Sources for problems under the flywheel included dirty points, bad magneto coils, cracked plug wires, or oil coating the points. <br /><br />One other possibility is a sheared crankshaft key, but you'd discover that when you pulled the flywheel.<br /><br />Let us know what you find.

 

[CATransplant]

Re: 40HP Big Twin will not start

I just can't get a jump on your posts, Paul. I'm typing away, then when I come back, there you are. Lots of help here for the Big Twins, eh?

 

[jchrans]

Re: 40HP Big Twin will not start

Thanks so much for your prompt replies. I do have a clymer manual. The battery is good and still has a full charge on it. Wierd, I know... I checked the voltage using a GB "GDT-185A", for which I have to get batteries for as one fell out and I can't find it ... it's always something! Unfortunately I don't remember which plug came out of which cylinder anymore (sorry, dumb I know). The one that was dry looked black/brown in color and when I tried cleaning it it didn't clean off. The other had a coating of brown oil on it which wiped off when I cleaned it. It looks new now, the other still looks burnt.<br /><br />I can attempt the compression check again ( as well as testing for spark) using a higher setting on my battery charger, as it has a 12V/225A setting as well. Should I try this?

 

[Paul Moir]

Re: 40HP Big Twin will not start

Yes, that will prove the starter is bad. When you've got your batteries for your meter, let us know! <br /><br />PS - it sounds like you were running real rich in one cylinder (the goopy plug). Try unscrewing the fuel pump from the engine (it should be held on by two screws) and pump up the primer bulb. If any fuel comes out the little hole in the back of it, that's probably the source of your stall.<br /><br />CATransplant - no worries it helps to have lots of help. Good thing you didn't overlook how he was doing the spark test like I did.

 

[jchrans]

Re: 40HP Big Twin will not start

Paul ... I am a she ...<br /><br />Okay, I used the charger on the higher setting and got crankage! Did compression check and got 105 on both cylinders(closer to 110 on the top one). Did spark plug test, got tiny little sparks on both pul wires. Put those same plugs back in, cranked it with the 12V/225A charger and it still would not start.<br /><br />I went to the store(s) and got new J4C plugs and batteries for the tester. I am now ready (as soon as the rain stops) to go out and try the new plugs and check out the fuel pump. What else should I be looking to do now?

 

[Paul Moir]

Re: 40HP Big Twin will not start

Sorry, my apologies for being presumptuous. I suppose when we can't ascertain gender, we assume our own. Well, I did anyway. <br />With the plugs out and the engine cranking, see how far you can pull the spark plugs from the block and still get an arc. I know this has you doing three things at once so you might need to rig up something to hold the plugs. If the spark is really weak and won't jump far, it could indicate that the flywheel key partly sheared when was misfiring, or the points got sprayed with oil from a blown top seal. This is presuming those wires that CATransplant and I were talking about are disconnected. With them out of the picture, that rules out the kill switch and safety switch wiring, which is always suspect.<br />It's really hard to give the right impression of how strong these sparks should be. They're normally fairly weak, as it's a bit of a weak magneto. It doesn't really compare to modern auto or lawnmower type ignition systems.<br /><br />Tell us what you find out about that fuel pump. The plugs firing end ought to be the same when everything's running properly.

 

[CATransplant]

Re: 40HP Big Twin will not start

New plugs could actually do the trick. If not, and the fuel pump passes Paul's test, you may have to dig in a little further.<br /><br />Since you are getting a spark, those kill switch wires were probably OK.<br /><br />Paul's right about the spark. What you described sounds pretty much what my spark looks like on a similar outboard, and mine runs great.<br /><br />You say you were running really slow when it died. Did the engine give a strong jerk just as it died? A sneezing sort of thing? If so, then the odds are that you'll be dealing with a sheared crankshaft key.<br /><br />Is this an outboard you've had for a long time? If so, what work has been done on it recently, if any. If not, do you know any of its history?<br /><br />You're in really good hands here. Paul's an expert on these Big Twins, and I'm getting there, since I've been working on mine. If it was running before, it'll soon be running again. Not much to go wrong with these fine old outboards.

 

[jchrans]

Re: 40HP Big Twin will not start

I tested for spark and it was pretty good. The spark jumped about 1/16" (I finally found a part of the block that was not painted). I tried starting the motor with the new plugs and it still would not start. I then checked the fuel pump and it is not leaking. I unplugged the vacuum switch, and it still would not start. I left that unhooked and then unhooked the safety switch ... it still isn't starting. Now what?

 

[CATransplant]

Re: 40HP Big Twin will not start

Uh-oh! OK, now try putting some pre-mixed fuel and oil in a spray bottle and spray some into the carburetor throat with the choke wide open. Try to start the engine again. It should try to start up. If not, we'll move on to the next step.<br /><br />Did you see my questions about how long you've owned the outboard and about what work, if any has been done to it recently? Also, when the engine died, did it give a big jerk or a backfire out of the exhaust or carburetor? <br /><br />One step at a time. We don't want to pull the flywheel until it's necessary.

 

[jchrans]

Re: 40HP Big Twin will not start

I'm sorry, I should have addressed your questions on those things. I bought the motor early last spring off of ebay from Mr. Outboard. It's run great since I bought it (with the minor exception of it not having a shear pin in it when I first took it out ... that was interesting ...). I only know I winterized it and then this spring I replaced the plugs and the lower gear oil.<br /><br />To be honest, I'm not sure if it made a jerk or not. I think it might have because I remember briefly thinking I might be in too close to shore with it in gear since I was going to attempt to beach it instead of throw out the anchor. But there was no backfire, I just remember putting it in neutral and then it conked out.<br /><br />Now I'm going to go try spraying stuff in it ... will be back momentarily.

 

[jchrans]

Re: 40HP Big Twin will not start

Okay, I am back. It did not work. Cranks and cranks but won't fire-up. What's next?

 

[CATransplant]

Re: 40HP Big Twin will not start

OK. At this point, the flywheel's going to have to come off. I'm betting that you've partially or completely sheared the woodruff key that positions the flywheel on the crankshaft. The same thing happened to me.<br /><br />This is compounded by the fact that you don't know the motor's service history. The guy before you may have pulled the flywheel but not torqued it down properly. The reason I asked if there was a jerk when it died is that's a pretty common precursor to a sheared woodruff key.<br /><br />With the flywheel off, you'll be able to also inspect the coils, points, and condensors. It's not all that expensive to replace them all. If the coils are old and cracked, then it's time to dump 'em and put on the new ones from Sierra Marine, which are green. With the flywheel off, you might as well replace the points, too and start fresh.<br /><br />The other possibility is that the upper crankshaft seal is bad. If that's the case, there'll be oil up there, but I doubt that, since you have some spark.<br /><br />There is a good thread here on flywheel pulling and replacement:<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=28;t=029310#000017 <br /><br />Paul Moir will no doubt be along shortly to let you know if I've missed something.

 

[CATransplant]

Re: 40HP Big Twin will not start

I have to check out for the day, although I may try to get back this evening. We can help you with parts numbers, etc., and answer virtually any question you might have.

 

[jchrans]

Re: 40HP Big Twin will not start

Thank you so much CATransplant. Can you or anyone please tell me where I can find the woodruff key in the manual? There is nothing listed in the index for it ...

 

[Paul Moir]

Re: 40HP Big Twin will not start

It keys the flywheel to the crankshaft. So it's underneath the flywheel essentially. To get to it, you'll need a flywheel puller. I use a cheap automotive 'harmonic balancer puller' with three 1/4"-20TPI bolts:<br />

<br /><br />Spark seems too weak then?

 

[CATransplant]

Re: 40HP Big Twin will not start

Paul's got the picture. The thread I linked to has more to say about using those pullers. They aren't expensive. You'll also need a flywheel holder and a torque wrench. You can rent or borrow what you don't have. The flywheel holder is a cheap item at auto stores.<br /><br />It seems a little scary (it sure did to me) but it's not that horrid a job.<br /><br />BTW, the picture Paul offered won't look just like your engine. the puller works the same way, though.<br /><br />Check your manual, and read the thread I linked to. There are other threads here, too, on flywheels. Just search this forum for Flywheel and you'll find 'em all.<br /><br />Give yourself an hour to get it off, an hour to replace what needs replacing, and another hour to get it back on. You'll be working slow, since it will be your first time.

 

[jchrans]

Re: 40HP Big Twin will not start

I have it off ... the puller thingie wasn't much help, it fell off and I just tapped the flywheel lightly under both sides and it popped off. At least I have the puller if I need one later.<br /><br />So, I have pictures of what's under the flywheel ... how do I get them on here? And what's next?