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Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 7:01 pm
by Mad Cow
I guess I'll change the filter, if not then I'll get another pump.

And my flat exhaust note I mean it's really dull and muted.

Also, it doesn't start if the VAF is unplugged, if that means anything.

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 7:38 pm
by SuperK
unplugged VAF won't determine whether it's bad or not.
If the car gets to the point where it doesn't idle or having problems keeping it from stalling, remove the VAF and try cranking it. but don't get out of the car. It should just rev UP UP UP UP UP.

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 7:45 pm
by _-Night-Shade-_
By the way, I've never heard of anyone being able to tell if they're rich or lean by listening to the sound of their exhaust :?

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 8:03 pm
by SuperK
You really can't, nightshade. but if it's the exhaust sound I'm thinking of, I know that it sounds WEIRD.

And if it sounds the way I think it sounds, than that'd be the VAF.

So I am going on a limb here and saying, "I understand how your exhaust sounds"

because it's just a plain weird sound.

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 9:46 pm
by _-Night-Shade-_
Hmmm, here's a thought: maybe along the exhaust something came loose and/or is letting out some of the gases. That would explain any sound that may seem weird and would account for lowered performance. Might be a good idea to take a look underneath just in case.

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 10:42 pm
by Mad Cow
It's not an exhaust leak, that would be really obvious. And I can kinda tell the mixture by the exhaust tone, it's more raspy and sharp if it's lean and more dull and flat if it's rich, mind you I learned this on a single-cylinder carburated ATV so I don't know how well it applies to cars.

But ok I'll try a new VAF after I change the fuel filter.And what could cause it to not start with the VAF unplugged?

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 11:11 pm
by _-Night-Shade-_
Maybe that's just the way it's designed?
Lol wtf you can't have a 1 cylinder engine :lol:

Re: Seriously bucking under full throttle

Posted: April 29th, 2009, 11:31 pm
by Daveb
You can easily tell if your rich or lean by checking a spark plug. If you run too lean for too long you will know about it for sure. :lol:

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 12:04 am
by Mad Cow
Yea I know the spark plug test, but mine was weird, I've never seen that before. It was black around the edge and the electrode was covered in this crusty beige-ish white stuff. But I checked that before I put in new O2 sensors, I put in new plugs with the O2's but I've always forgotten to check them.

And yes you can have a 1 cylinder engines, they're the standard for sport ATV's. Both 4-stroke and 2-stroke.

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 12:11 am
by _-Night-Shade-_
That makes no sense, what gives the piston energy to come back up? That's like riding a bike with 1 pedal. The lowest I've heard of is 2, like my buddy's snowmobiles.

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 12:24 am
by Mooneggs
_-Night-Shade-_ wrote:That makes no sense, what gives the piston energy to come back up? That's like riding a bike with 1 pedal. The lowest I've heard of is 2, like my buddy's snowmobiles.
lol good grief dude... do some googling... you are making this thread way off topic with your ignorance... :roll:

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 12:30 am
by _-Night-Shade-_
Haha okay man. Take it easy! Jeez :roll:

EDIT: Holy crap I just looked it up. I guess it is possible, would be interesting to know how the mechanics of it differs :)

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 8:11 am
by Mad Cow
They're the same except I think the flywheel is really heavy. But yea, let's get back on topic.

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 9:10 am
by Daninski
We use to call um one lunger's.
Anyway with a plugged cat your engine would run crappy at any RPM from what I've seen. You could check that by simply unbolting the cat and going for a spin.

Re: Seriously bucking under full throttle

Posted: April 30th, 2009, 9:43 am
by SuperK
when my VAF was bad it was black around the edge of the sparks and grey on the electrode...
I think it's when you've got spark and fuel... but not air.