Timing procedure on 40 hp

on my 1962 40 hp I believe the timing is off. I read the top secret files on this and just don't understand. I need it dumbed down. I don't know where the timing marks are, or how to advance it. I don't know what the full spark timer advance stop screw is . Ihave timed vehicles before, I just wish there were some diagrams somewhere. Can anyone educate me? Thanks Ronnie

Re: Timing procedure on 40 hp

the timing marks are there! but if you want to do a generic setting, just align the rubbing block of the points with the keyway in the crank, and gap to 0.020. make sure the points are spotless clean. you can go one step further with a multi meter or test light and use the marks, or you can pm F_R, and get one of his timing fixtures and time it like it would be done at a dealership.....but with a better made tool. ( great price too!!)

Re: Timing procedure on 40 hp

I did buy that tool, but I thought I had to set the advance first or at least the throttle sleeve and screw that is now flapping in the breeze

Re: Timing procedure on 40 hp

There is no full advance timing adjustment. The armature plate rotates till an arm on it bangs up against a projection on top of the cylinder block. That is full advance position. OK, now that it is at full advance position, the vertical throttle assembly on the side of the engine should be just ready to push on the set collar on the rod going to the carburetor. Continued movement of the throttle control will push on that rod, which opens the carburetor throttle shaft all the way.

Going back the other way, first the carburetor closes down somewhat (but not completely). That is "cruise throttle position". Continued movement toward slow retards the spark and continues to close the carburetor via the cam on the bottom of the armature plate.

Dead slow idle speed is controlled by spark advance (retard, actually).

Your timing fixture sets the breaker points timing in relation to the magnets in the flywheel. That only has a minor effect on spark advance.

Re: Timing procedure on 40 hp

+1. The timing is set mechanically. Here's a great ignition rebuild link. It's for a different model, but all the steps are the same.

3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

Reviving a Vintage Big Twin - Part 1

Magnetos

Re: Timing procedure on 40 hp

Thanks Guys, Your explanations really help me to understand. I don't just want to fix it I want to understand. The one questions I have is: The cam on the armateur plate and the follower ( rubber wheel) never touch each other, what is their purpose? do I need to adjust anything to get them to work. Right now the motor will run, Both cyl are firing but when I give it gas she hesitates to the point of dying out. I had to close the choke to get to full throttle, The carb was completely rebuilt several times and unless something new happened Im pretty sure its all set. today I will try setting with the timing fixture. Thanks

Re: Timing procedure on 40 hp

Hello again quagmire (gigidy). The cam on the armature plate should be contacting the rubber roller on the carb which opens the butterfly valve such that the valve is closed in the OFF position, but opens as you roll on the throttle. If they are not touching, you'll need to adjust the armature plate. There should be two small screws on its underside. Loosening them a bit will allow you to adjust the armature plate outward until it touches the roller. That may be why the motor is running rough. However, if you're having to choke the motor to get it to run, that means the motor is starved for fuel and the fuel/air mix is way too lean (i.e. not enough fuel to air). Choking the motor should actually flood the motor and kill it. It sounds like you may have a fuel delivery issue as well. I would try adjusting the idle on the carb. Backing the needle out will fatten the mix (increase the ratio of fuel to air) which should help.

Re: Timing procedure on 40 hp

Thanks, something is not right with that roller assembly. I tried to adj. it out but its a no go. I have several of these motors lying around for parts so ill poke around and see if I can tell whats wrong.

Re: Timing procedure on 40 hp

There is a mark on the cam on the armature plate. Unlike most motors, the throttle roller DOES NOT start to move when aligned with the mark. There is a pointer on the intake manifold, to the left of the roller. The carburetor throttle shaft should just begin to open when the cam mark aligns with the pointer. There are two different ways of adjusting that. The easiest is an eccentric bushing in the throttle shaft lever. Loosen the screw and turn the eccentric.

If yours isn't even close, something is holding it open. You will have to inspect it and use good old common sense to figure out what that something is.

Re: Timing procedure on 40 hp

Well one of the problems with buying a 50 year motor is you never know what the guy before you did. The throttle cam was not the right one for the motor, and the butterfly valve in the back of the carb is shot- doesn't close all the way. and a mounting screw gone. I have another carb and another armateur plate. I will redo everything when I get time this week and report results, Thanks for all the help. Ive never had so many things go wrong with one motor. Ronnie

Re: Timing procedure on 40 hp

After another week of working on this pig I think I finally figured out what the problems were. There were several witch made diagnosing very difficult. When I first tested, I put spark plug testers on and ran, the bottom calendar was loosing spark intermittingly . The first test I tried was to disconnect the cut out switch which was connected to this cyl. no difference. So I went right to the coils, one was weak, so I swapped with the other to see if the other cyl. would cut out and show me it was the coil, no difference. at that point I changed the condensers, points, wires and everything else on the armature plate, it seemed to run a little better but same cyl. would go on and off at higher rpm and eventually would go back to same cond. I tried swapping flywheel, no difference, I then swapped out The armature and put different (tested) coils, wires another new set of points and everything else on the plate ( I also bought F_R's timing tool and set everything to perfection. NO DIFFERENCE, I put the gun to my head and put my finger on the trigger and thought before I do this let me start from the beginning one more $%#*@ time, I pulled the wire off the cut out switch again, and this time it ran perfect???? I put the wire back and the bottom cyl. would cut out when I gave it a little gas. So I came to the conclusion that the cut out switch and the points on the same cyl. crapped out at the same time. That would explain why when I pulled the wire on the cut out switch the first time it continued to stumble due to dirty points. One of the guys said they almost never fail. Well they do fail. The other problem I had with the throttle roller not contacting the cam, turned out the butterfly valve in the back of the carb was slightly out of position and not closing tightly , holding the roller away. and finally the problem I had with the float contacting the side of the bowl and holding the needle and seat open was due to the fact that the holes drilled into the carb that holds the pin that the float pivots on were crooked, so no matter what float I put in it would malfunction. I'm not sure what I did to deserve all this at once, but I hope its over for a while. I write this for all the guys who tried to help as a way to say thanks and maybe if some of these issues happen to you, you can check the things that broke on me. Thanks all , Ronnie