[AT] Tractor Question - 420 JD

Mike Sloane mikesloane at verizon.net
Fri Aug 8 03:54:37 PDT 2008


Instead of WD-40, these days I use an unlit propane torch with the valve 
cracked open. That way you can direct the propane right at the various 
points around the manifold and the carburetor. In addition to warping, 
look for pinholes in the casting and gaskets that aren't sealed 
completely. You need to cover the entire area of the intake from the 
head to the carburetor, including the throttle shaft itself. A worn 
throttle shaft/bushings will allow air to get past and cause a lean mixture.

Mike

Lew Best wrote:
> Don't know if it'll still work as I'm told that WD40 has been
> re-formulated but in the old days you could spray it around the manifold
> contact places, etc. with an engine running & any vacuum leak would make
> an engine speed up quite noticeably.  Ether starting fluid should do the
> same but would have to be kept plenty far from the carb intake to avoid
> a "false alarm."
> 
> Lew
>  
> 
> -----Original Message-----
>  
> Thanks for the replies.  It is good to know that at least it is the
> right 
> one.  I have cleaned with carb cleaner and blown out several times over
> the 
> 15 years I have owned it.. I took it to the place that Dennis Polk uses,
> and 
> had it boiled and new jets, still same thing.  I had heard of the place
> in 
> IA and was thinking of trying them.  About a vacuum leak, I did a ring
> job 2 
> years ago, and used all new gaskets, so it should not be leaking air. I
> did 
> use the same manifold, so if it is wrapped, then I would have the same 
> problem.
> 
> I will keep plugging away, thanks again
> 
> 
> 
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