318 making weird noise

[firefighter3516]

I am not sure on how to explain this but here goes. I have 318 with a carter 2bbl when I shut the motor off sometimes it spits and sputters and sounds like it is sucking alot of air, and takes a second or two to shut off.    It doesnt do it all the time. Also it is running on points if that is any concern. 

[Brock Samson]

dirty gas will do that, it's called dieseling.. carb cleaner/ing better gas, blowing out the carbon with a strong mash of the gas once warmed up will help.

[terrible one]

From what I've learned, this can be caused by a number of things, including:

overheating, causing the fuel to ignite without a spark because it's so hot
carbon buildup which heats to wild temperature and ignites the fuel when the engine is shut off
off timing (this caused my '76 500 to diesel before I tore it down)

I'd check the timing out first. . .

. . . oh and I don't know what I'm talking about most of the time. 

[firefighter3931]

  Those are good things to look at....also check to see if the carb is leaking fuel from the bossyers after the engine is shut down. This is often caused by a sticking float or the float level is set too high.


Ron

[firefighter3516]

Thanks everyone I will looking into some of these things. I will check the timing if I can find someone to borrow a light from. And a question how do you know if it is getting to hot my temp gauge says it is fine anyother ways??? I hope it is not carbon build up because I rebuilt the the engine only a year ago. I will also check the carb the next time it does it dont know when that will be because it only does it maybe once every 2 weeks.