Motor Still Won't Fire After New Ignition Components and Carb Rebuild

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Okay, latest update. I pulled the flywheel and checked the flywheel key; it's still intact, not sheared. Next, I pulled the carb and mostly disassembled it again. Hit all the passages and orifices with carb cleaner, blew dry with compressed air, and reassembled. While the carb was off, I re-installed the brackets and starter motor, then reinstalled the flywheel after double-checking the gap on the points (both 0.020"). Torqued it to 65 ft-lbs and removed the spark plugs. Grounded one plug wire to lower unit, connected other plug wire to spark tester, stood back and hit the button.

First, I spewed gasoline everywhere. Apparently the fuel pump works fine. After cleaning up that mess, disconnecting the fuel line, and emptying what little fuel was in the hoses, I tried again. Absolutely zero spark this time around. I only tried one plug; when I saw there was no spark, I just shut the workshop down for the night.

So color me confused. Last time around, I had good spark on both plugs; after pulling the flywheel to check the shear pin, and pulling the carb to re-clean it, I have no spark.

Advise away.

 

[HighTrim]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

I will say my opinion again, I dont think you have a fuel delivery problem at all like you thought.

Ensure the ground is good though, something like a clean head bolt. If there is still no spark, ensure the points are clean, use acetone and then run a clean business card, paper bag, dollar bill etc... through them. Are you getting continuity from the coils ground wire to the end of the spark plug lead?

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Yeah, after tonight I don't think I have a fuel delivery problem either. I delivered it all over the place...

I'll give it another go tomorrow night. Clean the points and check continuity between the coil grounds and the plug leads (is the ground the green one, like in residential wiring? Or the black one under the screw?).

 

[HighTrim]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Measure from the black lead that is under the bolt to the spring inside the plug boot. Should get between 3000-8000

This will tell you that the secondary winding is not broken, and the plug lead ends are connected as they should be to the spring and the coil.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Okay, couple of things. First, before pulling the flywheel again, I re-tested for spark. This time I got good spark (I guess it's good - see videos below) on both cylinders. I suspect my test setup was too cobbled-together last night; I took a little more time doing it today.

Cylinder #1:

(Cylinder #2 video is in the next post.)

So, as of right now I haven't pulled the flywheel again until I hear different from you guys. Need to make a decision there soon so I can take the borrowed puller back to the auto parts place.

In other news, I got my new steering arm assembly in the mail today and installed it. MUCH better than the old one. So there's that. Carb is all put back together and waiting to be installed; don't wanna do that until I'm sure I'm finished screwing around underneath it.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Cylinder #2 video:

 

[Daviet]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Eliminate the jumper wire and attach the plug wire directly to the end of the spark tester.
It looked like to me that you are getting a nice blue spark, but it doesn't look steady. Redo your test and let the engine spin over a little longer, maybe 10 seconds or so, you should have a constant pulse of spark.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Okay, I'll give that a shot here in just a bit, after the kiddos are down for the night. I haven't gotten a "constant" spark on any of my tests; if that's the where the bar is, then something is definitely wrong. It's pulsed like you see in the video from the first time I tested it.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Okay, I re-checked it without the jumpers. I pulled the contacts out of their boots and gave them a bit of a squeeze with the pliers first, just to make sure I was getting good contact. Then tried both cylinders, one after the other. Didn't get a continuous spark on either. Actually fairly intermittent / jumpy - about like what is shown in the videos above.

When you say "constant pulse of spark," do you mean an actual pulse (i.e. on-off-on-off-on-off) or a constant stream (i.e. there's a blue spark as long as I hold down the starter button)?

 

[Daviet]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Every time the points open you should get a spark, or as you say on-off-on-off. The points should open every time the flywheel goes around. One rotation of the flywheel should open both sets of points one time. If the flywheel rotates 10 times, you should get 10 spark flashes.
The spark is controlled by the flywheel passing by the coils and the points opening and closing. Are your coils aligned with the mounting bosses, are the edges towards the flywheel clean, no rust? Are the magnets clean, no rust? Have you got the points set properly (.020)?
Are the mating surfaces between the points and mag plate clean, no corrision or oil?
When you installed the coils, did you cut a little off (1/4") of the plug wire to make sure of a good contact between the coil post and the plug wire? What shape are your plug wires in, any cracks or corrision?

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Yes, yes, no, yes, no, yes, pretty sure, no, no...

Coils are aligned with mounting bosses, although I've had to loosen the screws and the re-tighten while pushing the coils toward the shaft with my other hand; they want to ride outboard of the bosses. Edges toward the flywheel are clean - they're brand new coils. I'm not sure where the magnets are, but as I said, everything on the armature plate is new - so my guess is yes, they're clean. Points are set to 0.020" - I verified that when I had the flywheel off yesterday. There's no corrosion between the points and the mag plate - again, all new - but not sure about oils. I have big fingers - not sure how I would've gotten in that tiny little space to gum it up.

 

[Daviet]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Another thought, do you know anyone that has an outboard that you could attach your spark tester to and see what it is supposed to look like?

 

[Daviet]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

New coils, paint on the laminations? Run some sandpaper across the outside edges and polish them up. The magnets are in the flywheel, they rotate past the coil, polish them up also. Make SURE the coils are set properly, if theyare to far out of spec the system woun't work properly.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Okay, will have to tackle that tomorrow. I'm tapped out for tonight. Thanks to everyone for continued input. (And no - unfortunately, I don't have any buddies with outboards I can test my tester on. Would a lawnmower work?)

 

[Daviet]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Yes, give it a try and see what it looks like.

 

[Tim Frank]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

I double-checked the whole thread and couldn't see this mentioned, so I will.

Just for fun (and maybe more ) reverse the plug leads.
Easy to mix them and that would certainly stop it from starting.

It can happen in the best of families....

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Look at the mounting boss in this picture; can you see how it looks like it's been worn down? See the little ledge about halfway down the boss?

.

Is that normal? I really have to mash on the coils while I'm tightening the screws to get them flush with the bosses. I'm currently at work and can't find another picture to verify this, but I'm pretty sure all of the mounting bosses show similar signs of rubbing.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Re: reversing the plug wires...would that affect the intermittent spark I'm seeing on the spark tester? Doesn't seem like it would.

 

[nwcove]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Look at the mounting boss in this picture; can you see how it looks like it's been worn down? See the little ledge about halfway down the boss?

View attachment 165459.

Is that normal? I really have to mash on the coils while I'm tightening the screws to get them flush with the bosses. I'm currently at work and can't find another picture to verify this, but I'm pretty sure all of the mounting bosses show similar signs of rubbing.

the bosses are normal....not worn. coils need to be flush with the upper part. when you say intermittent spark, what do you mean? you should only get spark when the points open for that brief period of time.

 

[adt2]

Re: Motor Still Won't Fire After New Ignition Components and Carb Rebuild

Check the videos above...they show the spark. Daviet mentioned above that they didn't look right. I have no idea...first motor I've ever worked on. Unfortunately I'm not coordinated enough to watch the flywheel and the spark tester at the same time to see whether they jive.

When I get home tonight, I'll take some detail photos of the ignition system components. I think they're installed correctly, but there's a good chance I don't know what I'm talking about.