Briggs 4hp no fire-tried 2 new coils-nothing

bwm

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As title said, trying to repair Briggs 4hp push behind -belonging to sister. Was not firing when I got it-must be coil-tried spinning flywheel-not even a tingle. Ordered new coil-same thing-ordered another one-still no spark. I am experienced lawn mower mechanic from years back before electronic ignition-just getting back in the biz & stumped already. The kill wire is disconnected from coil & all rust brushed off flywheel. This is model-10A902 type-2180B1. On the parts look-up list it shows two different coils: Part numbers793281 & 793352. The 793281 is the one I bought It mostly resembles the one on the mower. When I swapped out the new for new the parts man assured me this was the correct coil. So, are these both defective, the wrong coil, is there a mismatch between coil & flywheel?, I was assuming that there should be some spark even if wrong coil. Enlighten me please!
 

Rivets

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I may be wrong, but when I look up your engine, I think you have the wrong coil. I feel that you should have a coil with part #496914, which is superseded to part number #591420.
 

bwm

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Thanks, Rivets, I checked the part numbers on the coil box & bill of laden & on box says: Ignition coil-4025-Replaces Briggs 496914-engine 3.5 HP- made in Argentina. On bill of laden: Ignition coil-Replaces Briggs 793281, 496914, 398593-7287. Does it matter that it says 3.5hp on the box? As far as looks goes, it looks identical to the existing one. Has electronic ignition changed coils so as to work on only specific flywheels, etc? I tried the new coil on 2 different mowers & no spark on either of them either. Still baffled- wish I still had my old stash of extra parts lying around to try out! Thanks again!
 

Rivets

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Ok, you are correct, as both supersede to the same part number. Then let's check if it is installed correctly. Really isn't hard to check. One, is the tab for the kill wire on top or bottom? When mounted correctly this tab should be on the bottom, closest to the engine block. Two, are you sure that the air gap between the coil and flywheel set at .010". I would make sure that I would use the card which came with the coil. If you are sure that you have both of these done correctly and you get no spark, with the kill wire NOT attached, your coil is bad.
 

briggs

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also make sure that the kill wire is not grounding out on the block somewhere if it is it will not start ...I have also seen the safety switch mess up
 

Fish

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Sounds like you bought another coil that needs points and cond. to work. You just need the electronic version. Put up a pic of your coils to confirm.....
 

EngineMan

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There are no points and condenser fitted to a 10A902 and the *496914 part number is also the one that I have in the parts manual.
 

Fish

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There are no points and condenser fitted to a 10A902 and the *496914 part number is also the one that I have in the parts manual.

Yah, I notice now the A in the model number.

Put up some pics please, something ain't adding up!!!!

Like a newer style starter or something. 1 dead coil on a pushmower is 1 in a 1000, 2 in a row, very unlikely.

Something is wrong in your diagnosis or you model/part number. Put up some pics or tell the whole story.

Or more likely, you are not spinning the flywheel fast enough on your test.....

Ask your sister about that stump...... Seriously, it isn't adding up.
 

briggs

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Thanks, Rivets, I checked the part numbers on the coil box & bill of laden & on box says: Ignition coil-4025-Replaces Briggs 496914-engine 3.5 HP- made in Argentina. On bill of laden: Ignition coil-Replaces Briggs 793281, 496914, 398593-7287. Does it matter that it says 3.5hp on the box? As far as looks goes, it looks identical to the existing one. Has electronic ignition changed coils so as to work on only specific flywheels, etc? I tried the new coil on 2 different mowers & no spark on either of them either. Still baffled- wish I still had my old stash of extra parts lying around to try out! Thanks again!

check your kill wire check the kill switch and check to make sure the spark plug wire is not pinched that can cause it to ground out and install a new plug
 

Fish

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I haven't seen 4 h.p. on an engine for a dam long time.......... Some thing is up with that........
 
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