I am in need of Help!! I have a champion blower 400 and one over the gears snapped into 5 pieces and I haven't had any luck findings a replacement. It is roughly 4.5 inches across. Someone plz help me!!

Edited September 4, 20187 yr by Mod34
Moved to proper section

Ouch!  That one hurts to see.  That appears to be one of the straight-cut gears rather than the bronze worm driver so there is a very slight possibility that you can get a replacement.  

Gear specification can get really complicated---you have to determine "diametral pitch" and tooth count from the existing gear. Also pressure angle but that's not as hard a deal. There are sites online that will help you understand diametral pitch and how to figure that so I won't go into a long diatribe on the method.  Once you pin that down, you can search something like the catalogs of Boston Gear to see if such a thing even still exists.

Note also that in the past some odd gear pitches were sometimes used-- the world standardized on fewer options in more modern times.  That might make it a much more difficult project to find a matching gear from modern stocks.  

Obviously the best bet is to have a donor blower with one of the other gears bad to steal this one from.  Buying a new gear (if one can be had) is likely more costly than the blower is worth in the first place.  This one might be best as a donor for someone else's project at this point.

Is this your first experience working with old cast iron machinery?

Thomas Powers yes this is my first time working with old cast iron machinery.

Thanks for the advice kozzy 

I generally start by soaking the item(s) in a good penetrating oil---one better for rust than WD40---for at least a week.  I like to set them out in the NM sun so there is a heat cool cycle of 80 deg F or so and keep adding penetrating oil every day or two. Then for an item like that I would try a gear puller. If that doesn't shift it any under a REASONABLE amount of umph; I would try a second week. if after a second week no luck I would start thinking of gently and evenly applying heat.

Last visit to my shop I had a friend trying to remove a thoroughly rusted on nut from a trailer hitch ball---NOT CAST IRON and NOT PLATED (hence the rust).  Not having to baby it; after he couldn't get it to shift in the 6+" postvise with the large wrench; we popped it into the opening to a cave fire in the forge and a few minutes later he twirled it off with a small wrench.  Again NOT CAST IRON.

Cast iron can be amazingly fragile and in machinery; very hard to fix or replace 

Definitely not conducive to percussive maintenance.