Ringing out after adjust...

[dirtysouth]

OK so I checked my valve lash and went through the process of changing out the shims in my buckets. First timer BTW:naughty: Well, I fired it off after buttoning everything up and had the airbox off as I was letting my filter dry out. Here comes the kicker:eek:

I was hearing a metal on metal tap through the carb. At first I was hoping that this wasn't uncommon and the filter hid it so I opened it up a little hoping that it would quit. Well it was still ringin out after that but got a solid minute of run time.

Has anyone ever done this before? I assume that the intake valve(s) is smackin the piston. Do I need to check my cam timing. Oh and heres one thing that I wanted to know. When turning the crank counterclkwse to find TDC there are two vertical marks that show up with an arc line connecting them. The piston seemed to be at TDC through that arc but I used the latter mark. Anyway, It runs good at idle and off idle(except for the noise). Do I need to pull my head off and rebuild now? Live and learn...help me learn

[DirtDawg]

Probably what your hearing is the carb. slide rattling, it makes a good bit of noise that is more noticeable with the filter out. I doubt the valves are hitting the piston if it starts and idles good, don't think it would run very well or for long if they were.

[642MX]

Probably what your hearing is the carb. slide rattling, it makes a good bit of noise that is more noticeable with the filter out. I doubt the valves are hitting the piston if it starts and idles good, don't think it would run very well or for long if they were.

Your exactly right. The flat slide carbs make a bunch of noise. Normally with the air filter on and the seat in place you won't hear the carb much.

Good job with your first valve adjustment!

[dirtysouth]

Probably what your hearing is the carb. slide rattling, it makes a good bit of noise that is more noticeable with the filter out. I doubt the valves are hitting the piston if it starts and idles good, don't think it would run very well or for long if they were.

So if it sounds something like taking a spoon and tapping the top of the head or something....thats the slide in the carb??? I fired it up again and let it idle for a few secs to ease my doubts and still heard that sound. Use your imagination and try to hear a spoon tapping the head. It sort of rings out you know...its not just a dead thud:confused:

[642MX]

So if it sounds something like taking a spoon and tapping the top of the head or something....thats the slide in the carb??? I fired it up again and let it idle for a few secs to ease my doubts and still heard that sound. Use your imagination and try to hear a spoon tapping the head. It sort of rings out you know...its not just a dead thud:confused:

Pull the boot off the back side of the carb and tap your finger against the slide. It will make the same sound that your hearing. Its totally normal.

[dirtysouth]

Pull the boot off the back side of the carb and tap your finger against the slide. It will make the same sound that your hearing. Its totally normal.

I am gonna try that man, and if it works, then I am gonna be so freakin stoked. If not then I will know what to do next and I am not gonna be lookin forward to it:excuseme:

Thanks

[dirtysouth]

Anybody else heard this before?

[TD-3]

Anybody else heard this before?

I have on my YZ450.....as stated, it's most likely the carb slide. If you put your ear near the airbox intake you can really hear it rattling.

[porterdog]

A mechanics stethoscope ($10 from Sears) will *really* help you out here.