I have a Rochester RP 1 barrel carb I'm trying to rebuild. It was removed about 25 years ago from a running vehicle. It has a lot of varnish inside and a black colored "coating" for lack of a better word in part of the bowl. The black coating flakes off but not easily. What should I use to clean this stuff out? Carb cleaner barely made a dent in it.
I soak mine for a week in lacqer thinner and then use Gumout carb cleaner in the aeosol can with the little red stick you stick in the aspirant. You may have to do it a few times but it will eventually all come out.
I use an old crock pot with about a 50% solution of Simple Green to clean motorcycle carb parts. Cleans like nothing I've ever seen. For a larger body carb I'd just use a big old covered kitchen pot and boil it on the stove on low. If your ol' lady objects just use a camp stove outside.
soda blasting works very well if carb cleaner will not do the job, info here: http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/
I use McKays. I find it stronger than Berrymans. You have to be careful with carb dip. It contains mostly water with a strong Base soap. Kinda like Draino. The water in the dip can corrode the aluminum alloy in the carb. Plus the base factor in the soap its self is caustic to the alloy. I left a single bbl Onan generator carb in parts dip and forgot it for the weekend. It not only opened up some small pits in the bottom of the float bowl but, the sides and outside as well were now pitted. It was just totally ruined. My teacher in trade school was a retired GM engineer and told us no more than 1 hour with new dip on a normal use carb and for sure no more than 24 with even real dirty dip and a problematic carb. Parts Dip should soften varnish, even in the passage ways in an old carb in a few hours. Remember to check all the passage ways with air. Use a full face mask, compressed air will blow parts dip and varnish out in a blast and you'll have a good splatter which ever the way the opening is pointed!
The Jalopy Journal
