weird ignition problem

[joeyfigo]

Hi hope someone can help. Have a weird problem with a old 5hp BS electric key start lawnflite. It starts ok with the pull start after a few pulls but will not start on the key start.....absolutely no spark at all. anyone have any idea what the issue could be. I'm thinking the magneto coil? The battery is brand new and spins it over big time but no spark. Plenty of fuel getting through. Spark plug brand new.
Thank you

 

[mechanic mark]

yes i would test coil!

post model xxxxxx, type xxxx, trim xx, numbers from engine.

https://www.briggsandstratton.com/e...ualSearch.html?searchrequested=128807-0157-01

 

[joeyfigo]

Hi Thank you for replying. The numbers are 128807 0157 01.

Cheers

 

[Rivets]

Could be the key switch is bad. It may be grounding the coil in the start position.

 

[Tinkerer200]

Could be the key switch is bad. It may be grounding the coil in the start position.

"It starts ok with the pull start after a few pulls but will not start on the key start.....absolutely no spark at all. "

Agree.

Walt Conner

 

[joeyfigo]

Ok thank you re the key barrel. Never even considered that part. I'll try a hot - wire start by passing the key and see what happens.

 

[bertsmobile1]

Don't know how this key start works.
I have just finished a key start Victa with a charging coil as part of the ignition coil.
Same story, pull started before the rope gets to the end but no spark on the key.
Ended up being a short between the charging windings & the magneto windings inside the coil so fitted a mains charger from Talon to it and swapped the coil for a standard one.
These are a little different because the ignition cut out is built into the carb so all that the key does is connect the charging windings to the battery and crank the starter.

 

[joeyfigo]

Wish I was more technically minded to properly understand it all. This mower has a magneto one side of the flywheel and another smaller one opposite. Turns out this little one is the alternator to charge the battery. I removed it and tried to start it but again spins up nice but no spark. Not sure how to bypass the key ignition.....It has 2 wires only and was thinking that I can pull them off the ignition barrel and touch them together ??? Other than that I guess I can buy a new magneto and key barrel and hope it cures it.