61 40hp Lark III bad starter?

[freddyray21]

I am thinking of trading for a late 50s early 60's 40 hp evinrude. I was told by someone that I needed to be weary of the late 50's but after 61 they were okay. I was told the late 50's and up to 61 were bored out 25 hp motors with the original cranks and the cranks wouldn't hold up to that much horse. I don't know yet what year this one is and will find out on Saturday, but thought I'd be forwarned if anyone had any information.

 

[F_R]

Re: late 50's early 60's evinrude 40 hp

Re: late 50's early 60's evinrude 40 hp

Inaccurate, but some truth to it. The 40 didn't come out till 1960. The early ones, 60 and '61 did have the smaller crank, which was changed on the '62 models. I was a full-time outboard mechanic at the time and I have to tell you that I never saw a broken crank, though I understand that it did happen. So they didn't ALL break, and in fact there are still a lot of them running today. More important than worring about breaking the crankshaft would be what is the rest of the motor like? Have the coils been replaced? If not, they need it. How about the water pump? Has the motor ever been overheated? The paint should NOT be burned or discolored on the powerhead. How about a compression check or a test run? I reckon that as with all motors, you pays your money and you takes your chances.

 

[freddyray21]

Re: late 50's early 60's evinrude 40 hp

Re: late 50's early 60's evinrude 40 hp

I'll find out Saturday. I am going to trade the 60 V 75 Johnson for the 40 hp. Long story, but read the post on the V 75 I posted. I think the 75 will be a better motor for the boat and the 40 will suit me just fine.

 

[freddyray21]

Re: late 50's early 60's evinrude 40 hp compression numbers

Re: late 50's early 60's evinrude 40 hp compression numbers

Went out and traded for it today. We didn't have a battery or pull rope, but with a screw in compression tester and turning the flywheel by hand we got 60 lbs of compression out of both cylinders. A little oil sprayed in the cylinder raised the compression to 90 and even in both cylinders.

 

[freddyray21]

Re: late 50's early 60's evinrude 40 hp

Re: late 50's early 60's evinrude 40 hp

btw it is a 61 40 hp Lark III

 

[freddyray21]

61 40hp Lark III wiring diagram

61 40hp Lark III wiring diagram

I have ordered the manual, but was wondering if anyone had the wiring diagram for this until the manual gets here. I traded for it with an ignition switch but no key so I am particularly interested in the wiring for the key switch. I want to hot wire it to see if I can get it running and don't want to cross the wrong wires.

 

[Paul Moir]

Re: 61 40hp Lark III wiring diagram

Re: 61 40hp Lark III wiring diagram

This should do:
http://www.shareaproject.com/fullImages/2627.jpg

If there's no generator, cross out all the fuses, the regulator, ammeter, etc. That will greatly simplify things. To compare, you might want to have a look at the schematics I drew for the 28hp. They're virtually identical to the 40hp and a little more clear I hope:
http://www.files.bz/files/3414/28schematic.PDF

No Generator:
http://www.files.bz/files/3414/28sch_NG.cdr-CorelDRAW.pdf

It is absolutely critical that you use a keyswitch made for an outboard motor. The engine is stopped by shorting together the two black magneto wires, otherwise they're left alone. If 12v finds it's way down them it'll blow out an ignition coil.

 

[freddyray21]

Re: 61 40hp Lark III wiring diagram

Re: 61 40hp Lark III wiring diagram

so if I unhook the two wires from the keyswitch I have the circuit won't be grounded and I should have spark if everything else is fine?

 

[Paul Moir]

Re: 61 40hp Lark III wiring diagram

Re: 61 40hp Lark III wiring diagram

Yes. But a little ways of an explanation:

While grounding one of the black magneto wires will cause one cylinder to loose spark, the keyswitch does not actually ground the wires itself. Rather it connects the two wires together. This grounds each side of the magneto out through the complementary set of points on the other side. The idea is this will kill spark on both cylinders, stopping the engine easily.

 

[freddyray21]

Re: 61 40hp Lark III min revs for spark?

Re: 61 40hp Lark III min revs for spark?

what is the minimum revolution I should have on this motor to generate a spark?

 

[Paul Moir]

Re: 61 40hp Lark III min revs for spark?

Re: 61 40hp Lark III min revs for spark?

It's a guess since I've not actually measured it, but with things set up ideal, 50-100 rpm over a .030" gap. Life is good if you can get it to jump over 1/4" gap at pull or cranking rpms. (typically 300 and up)

 

[freddyray21]

Re: 61 40hp Lark III bad starter?

Well here is the latest. Hooked a battery to it. With the plugs out checking compression the starter spins fine good revolutions. I have good compression although lower cylinder has no spark. Probably the coil, but that is not my major concern. When I put the plugs back in the starter will barely turn it past the compression stroke. I put the battery on charge all night and tried it again this moring and the same thing. It is possible I don't have the battery charged fully I suppose, but any ideas. I hooked jumper cables to the battery and that did not help. This motor sat in a barn for years so anything is possible.

 

[tashasdaddy]

Re: 61 40hp Lark III bad starter?

freddy, take the starter to a starter shop and have it tested. my be weak and need rebuild.

 

[steelespike]

Re: 61 40hp Lark III bad starter?

If you are mechanically inclined you can rebuild the starter yourself It may be as simple as a stuck brush.
check the bearings/bushings clean the commutater,don't use emery cloth.
you could take just the armature to the shop.They can test it clean the commutater and undercut the mica for less than a rebuild. replace the brushes.

 

[freddyray21]

Re: 61 40hp Lark III bad starter?

I am going to make sure I've got a good hot battery first, but I am inclined to agree with you guess. Years of non use could make it sluggish.

 

[freddyray21]

Re: 61 40hp Lark III bad starter?

DOPE turns out not a bad starter. Bad cable. The connections were cleaned up by me, but never thought about it being a bad cable. I got the manual and am going to let it sit for now until spring probably. We got an ice and snow storm going on outside and not thinking much about outboards now. Course first warm day.

 

[freddyray21]

Re: 61 40hp Lark III bad starter?

well back to bad starter. I replaced the cables and the starter turned fine. Went back out yesterday and messed with it to see if I could get it running and it was doing the same thing again. Buddy of mine who works on these thing thinks it might have a bad spot on the armature or a brush hanging up. He will tear it apart and let me know.