Author Topic: 400F won't start and backfires badly  (Read 625 times)

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Offline mrenfro

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400F won't start and backfires badly
« on: December 21, 2022, 07:50:21 AM »
I've got a 400F engine I installed into a 350F frame and trying to get it running in order to sell as a running 400F engine.  The rest of the 350F is crap.  Anyway, it doesn't have the starter motor so I'm having to kick it.  When I try to kick start it, it won't fire up but will intermittently either attempt to start or backfire.  Checked the timing, plugs, points don't arc when opened and closed so I assume the condensers are good.  The carbs were recently rebuilt and at this point I assume there's enough fuel to at least make it start even if it runs poorly.

Any help appreciated.


Offline carnivorous chicken

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Re: 400F won't start and backfires badly
« Reply #1 on: December 21, 2022, 08:20:25 AM »
switched wires from the points to coils?

Offline mrenfro

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Re: 400F won't start and backfires badly
« Reply #2 on: December 21, 2022, 08:27:33 AM »
aha!  I think you may have just embarrassed me!  haha  gonna check that at lunch.  thanks

Offline scottly

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Re: 400F won't start and backfires badly
« Reply #3 on: December 21, 2022, 08:30:47 AM »
Also, check that the #1 and #4 spark plugs are fed from the same coil (usually the left one) and #2 and #3 are fed from the other coil.
Don't fix it if it ain't broke!
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Offline mrenfro

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Re: 400F won't start and backfires badly
« Reply #4 on: December 21, 2022, 12:56:19 PM »
thanks

Offline ADW

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Re: 400F won't start and backfires badly
« Reply #5 on: January 03, 2023, 12:07:51 PM »
Soooooo...what's the result? Did you fix it?