Re: Best Solvent For Carb Rebuild
I've done carbs off small power tools, motorcycles, cars and boats.
I like using soak type cleaners, but you have to be careful not to overdo it. By soak type, I mean the gallon sized paint can kit with the lift out basket that almost all auto parts stores carry. This is water soluble stuff and smells like bug killer. It does a great job stripping off paint and cutting through varnish and light corrosion. Use appropriate personal protection equipment - you don't want to contact this stuff.
After soaking
metal only parts for a half hour at room temperature, remove the parts and give them a good blast with water. This washes off the solvent and loose junk.
From there, I blow dry with compressed air and pay attention to all the passages. I like to use fishing monofilament to snake out each and every passage, then hit them with canned carb cleaner spray (the kind with a straw). Berryman B12 is the best IMHO.
Fishing line is soft enough to prevent damaging passages, but it is firm enough to push out any crud. I have 10 to 80 lb line in my tackleboxes, so I can easily choose the size that barely fits. That makes it easy. Start with the largest passages first, since crud may be pushed into the smaller passages that intersect them.
Dry again with compressed air and use good lighting to see if recleaning is required.
Be careful with the soak type cleaners, as some carburetors have had resin impregnation for potential casting porosity. The soak cleaners can cut the resin and expose porosity which was previously sealed by the resin. 20-30 minutes is sufficient to cut through most varnish, gum and crud. Too much longer and you may remove impregnation resin.
If you have surface crud in the carb bowl(s) or exterior, you can rig up a homemade soda blaster. Basically, use a compressed air nozzle to draw baking soda through a flexible tube, like a sandblaster. When done, wash with hot water and blow dry with compressed air.
Here's a link to how to make a home made soda blaster for small parts.
http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/
For the rubber parts, use hot soapy water. It's always best to replace them, but you can get by reusing them in a pinch if they are in good shape.
