5247 (1980) won't restart. Carb adjustment problems?

[Gene123]

I've been trying to get a 5247 (1980) running. It has an F100 engine with "the late model" carburetor. I resolved the problem of gas leaking from the foam filter --- thanks to help from some of the fellows on this forum (Fireman, Two Stroke, & others). Good guys :thumbsup: I installed a new needle & seat as they suggested, primed it twice, and it started like a champ. I mowed for about twenty minutes, turned it off, and it wouldn't restart. Questions: 1. Is the .010" clearance between the coil and the flywheel crucial? I may have gotten it off a little. 2. If I got the float level off 1/16", would that cause the problem? 3. After setting the governor to real low rpms, I screwed in the "adjustable fuel flow needle valve" until it started stalling (or "hunting"), then I backed off on the screw about half a turn until it smoothed out. Could that adjustment be causing it to not restart?

 

[Fireman 123]

I've been trying to get a 5247 (1980) running. It has an F100 engine with "the late model" carburetor. I resolved the problem of gas leaking from the foam filter --- thanks to help from some of the fellows on this forum (Fireman, Two Stroke, & others). Good guys :thumbsup: I installed a new needle & seat as they suggested, primed it twice, and it started like a champ. I mowed for about twenty minutes, turned it off, and it wouldn't restart. Questions: 1. Is the .010" clearance between the coil and the flywheel crucial? I may have gotten it off a little. 2. If I got the float level off 1/16", would that cause the problem? 3. After setting the governor to real low rpms, I screwed in the "adjustable fuel flow needle valve" until it started stalling (or "hunting"), then I backed off on the screw about half a turn until it smoothed out. Could that adjustment be causing it to not restart?

Glad you got part of the problem fixed. Sounds like you have got a typical old Lawn Boy on your hands. Good thing we love these little machines, and show them a little mercy haha. I haven't had the same issue, but I would check to see if the exhaust ports are clear of any carbon build up. If that's not it, I suggest tinkering with the carb until you get it lined out. As for clearances, I use a business card to set the gap on the flywheel, and the float I just set to to level with the carb body. This has worked for me so far. Good luck!

 

[Gene123]

Glad you got part of the problem fixed. Sounds like you have got a typical old Lawn Boy on your hands. Good thing we love these little machines, and show them a little mercy haha. I haven't had the same issue, but I would check to see if the exhaust ports are clear of any carbon build up. If that's not it, I suggest tinkering with the carb until you get it lined out. As for clearances, I use a business card to set the gap on the flywheel, and the float I just set to to level with the carb body. This has worked for me so far. Good luck!

I'll try all that tomorrow. Using a business card to set the gap on the flywheel --- what a good idea! I sure appreciate your help, Fireman.

 

[dougw]

Might check and make sure it is getting spark. I have had ignition modules quit before. Also exhaust ports plugging up will make it low on power and smoke a lot along with hard to start.
Doug

 

[Gene123]

Might check and make sure it is getting spark. I have had ignition modules quit before. Also exhaust ports plugging up will make it low on power and smoke a lot along with hard to start.
Doug

Good idea. I hadn't thought about the coil suddenly going out. Do they abruptly go out, or do they slowly fade away?

 

[dougw]

I have seen both many times they seem to lose power but work for a while before quitting other times they work one minute then quit the next. Might check and make sure the wire to the switch and the ground are good and gap is correct then check it with a meeter before deciding it is bad.

 

[Gene123]

I have seen both many times they seem to lose power but work for a while before quitting other times they work one minute then quit the next. Might check and make sure the wire to the switch and the ground are good and gap is correct then check it with a meeter before deciding it is bad.

I didn't know a coil could be checked with a meter. How is that done?

 

[Two-Stroke]

... 3. After setting the governor to real low rpms, I screwed in the "adjustable fuel flow needle valve" until it started stalling (or "hunting"), then I backed off on the screw about half a turn until it smoothed out. Could that adjustment be causing it to not restart?

I'm not sure why you adjusted the needle valve that way. Did you read that in a manual? I'm not saying it's wrong but I've never heard of doing it that way.

I adjust the needle valve by testing how the mower performs under load (cutting normal height grass) while fully warmed up.

To get it started, it may be necessary to reset the needle valve (try turning it all the way in -- then out one turn) -- fiddle with it if necessary.

 

[hankthecrank]

1 preset altitude needle 1/2 turn from seat
2 start and let warm for 3-5 min.
3 place speed control to low
4 slowly turn needle CCW until engine running smoothly
5 place control to high, if not running smoothly turn CCW 1/8 turns at time till smooth
6 shut-off and immediately try to restart, DO NOT PRIME, should start within a couple pulls at both
low and high settings, if not contitnue turning needle 1/8 turns CCW to obtain easy starting.

This is from manual, good luck, looks like everyone pretty much have it covered. Fuel+ Air+Combustion+Ignition=VROOOOOM.

 

[Gene123]

I'm not sure why you adjusted the needle valve that way. Did you read that in a manual? I'm not saying it's wrong but I've never heard of doing it that way.

I adjust the needle valve by testing how the mower performs under load (cutting normal height grass) while fully warmed up.

To get it started, it may be necessary to reset the needle valve (try turning it all the way in -- then out one turn) -- fiddle with it if necessary.

Thanks, Two Stroke. I'll try that as soon as it stops raining. I don't have a manual. I've just copied bits and pieces from the internet. I've been reading a lot --- got so much swimming around in my noggin it makes me dizzy. :laughing: