Dieseling on shut down

[Beefer]

My brain seems to have abandoned me.

Motor starts and runs great, but Diesels when I shut her down. I know this is something (relatively) simple. Where do I start?


488R / Alpha I / Rochester Quad

 

[Silvertip]

Re: Backfiring on shut down

Re: Backfiring on shut down

Are you confusing back firing with dieseling perhaps. A backfire is loud report whereas dieseling sounds like a rough running engine and may quit with sort of a muffled "puff". Dieseling is generally due to idle speed set too high or not being allowed to idle for awhile after a long high speed run before being shut down.

 

[Beefer]

Re: Backfiring on shut down

Re: Backfiring on shut down

Like I said... my brain has abandoned me...

Yes, it's dieseling. :facepalm:

 

[RogersJetboat454]

Re: Backfiring on shut down

Re: Backfiring on shut down

-Idle speed too high.
-Wrong part number plugs causing a hot spot (acting like a glow plug).
-Carbon build up.

 

[halfmoa]

Re: Backfiring on shut down

Re: Backfiring on shut down

-Idle speed too high.
-Wrong part number plugs causing a hot spot (acting like a glow plug).
-Carbon build up.

Agreed +
-Overheating from blocked coolant passage
-Overheating from carb set too lean
-Incorrect octane i.e. 87 octane fuel in a high compression engine

 

[Beefer]

Re: Backfiring on shut down

Re: Backfiring on shut down

Thanks! Gave me some things to look at tonight. I run 87 octane mostly, and it only needs 87 per manual. Occasionally I run 89.

I'm starting with the carb adjustments.