Yep, standard 'Finish' detergent is the go. Good to hear you didn't blast the inner surfaces. Remember gloved hands when handling after washing. Apply paint as soon as possible after drying, no need to prepsol or solvent wash, just mask off the bearing and gasket surfaces and go.
Before you wash it, run a tap down all the threaded holes and blow out any caked in grit, grease, dirt and or remnants of silastic sealant etc as this crap will certainly not come out until you hit it with paint - Murphys law.
Use some expendable clean case screws (assuming M6) to dummy assemble the bare cases. I use a handful of cheap screws I bought from the local bolt barn for this job. Once dry, remove all the dummy fasteners and away you go putting Humpty back together again with your OEM fasteners.
It will also help to low oven bake the cases to harden the paint by evaporating the free solvents in the paint. Pre heat the oven to 100 C and suspend the cases from the oven racks for an hour or so (it might get a bit stinky in the kitchen). Avoid using a Gas oven for safety reasons, electric is best. Even hang the cases in the Sun for a day or so if you don't want to oven bake. Allow 8 hours of natural drying time before you bake or touch dry before you hang in the sun.
It is best to leave the painted parts a week to fully cure before you assemble if you can wait, this will ensure the paint will be fully cured to avoid damage when you assemble the cases.
In the meantime you could screw some dowels to a piece of ply or MDF which match to your engine mount holes to make a stand so the cases don't roll around the bench while you are installing the innards (use the case or a gasket to mark out the positions for the dowels).
Select dowel that fits nicely into the engine mount holes, cut the dowels to length so the case you are installing the gears and crank into is leveled and there is sufficient clearance for the crank spindle and selector shaft/ gear shafts etc to be fitted without bottoming on the base board.
Next use a few pieces of pipe or electrical conduit cut to length to slide over the dowels to create a shoulder that the case will be supported on (you can slip a large o/d washer over the posts you have made from the dowel to add extra support if need be). The material you choose for this should also be cut at the desired length to level the case as often the mounting bosses are at different levels - so a longer tube where the cases are narrow in the frame and shorter ones at the wider points if you dig me.
Surgically clean is the way to go, shout yourself some disposable nitrile gloves or food handling gloves for handling bearings and gears. Be patient and you will get great results plus most of the bits you need to put together a trick stand are cheap bunnings items or perhaps scraps you can salvage from home or work. Sing out if you want me post a few pics of my home built stand for ideas.
Cheers Jason
