Poofing Sound in Exhaust

Southerncomfort

Cartaholic
Ive recently noticed it at start up now, and as it shuts off, not a backfire, but a poofing sound.
Last owner had over tightened the exhaust valve and I'm being paranoid about things like a burnt valve.
Right after I got it I checked it and cold it was like .002-3 and it's supposed to be .004

Is the poof normal? Carburetor letting in too much fuel and it's igniting in the exhaust? Me being over paranoid?
 

dirtysouth

Cartaholic - Sponsor
I think you're right. See if the butterfly is closed all the way when ya shut down. Don't sound like anything serious :twocents:
 

Southerncomfort

Cartaholic
Yes it shuts.. but now it sat for like a year, I took the carb off and cleaned the bowl and he so called cleaned the ports out and it ran fine with a backfire from time to time.
I reset the valve clearance and no more backfire but it's doing this fart thing now.

I see things differently than he does, he's a junkyard lawnmower mechanic, I'm a nit picky motorcycle guy so he drives me nuts with the "oh it'll be fine like that" kinda outlook.

Doesn't have to be perfect by any means, but it needs to be right ya know.
 

country

Active Member
I have removed all of the idle screws from our 68 carts to eliminate the carb dumping fuel after the pedal is no longer depressed those engines were used in several applications so check to make sure the idle screw is not turned in keeping the butterfly from fully closing
 

Southerncomfort

Cartaholic
Ahh gotcha. Yeah it's closing but on the idle screw. I'll back it off and see if that helps. Good to hear it may not be anything bad.
 

country

Active Member
That is most likely your problem I would take that screw all the way out unless you intend on buying the $900 kit to make your cart idle
 

Southerncomfort

Cartaholic
I'd soooo want it to idle and had it all wired up to do so, but wouldn't idle low enough to shift it into gear. And I don't want to respring the clutch as I like the low end power.
And can't afford a whole new clutch setup.
 

Todd T

Member
Is there any way to get the Fj 400 to idle with the belt off? I can get my Fe 290 and Fe 340 to idle but I'm like SC, I would like the Fj to idle too.
 

Southerncomfort

Cartaholic
I can get mine to idle, just not low enough.
Too low and the starter kicks in and just as the starter let's up the clutch is moving enough that I can't get it to shift.
I hate the micro switch and 2 throttle cable setup. But it's the best I can do.
 

Todd T

Member
On the Fe, I can bypass the micro switch and get them to idle but the Fj just stumbles and dies even with a different carb. The Fj is on a 2012 Cushman 800. It's like the low speed circuit in the carb is not jetted to let it idle. Even tried different jet because I was also having a proof from the exhaust.
 

country

Active Member
They make a kit that changes the clutches and replaced the micro switch with a different ignition but the kit is pricey the clutches are the reason they dont idle that same motor goes in
 
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