Top end rebuild under way! Cleaning advice?

Hi guys,

So I dismantled the top end of my '81 Special on the weekend and was totally stoked with a) myself! and b) the condition of my engine.

The problems appear to be exactly what I assumed - a broken shift drum stopper spring, and an EXTREEEEEMLY filthy right-side piston, head and valves from a previous (and obviously long-standing) carburetor issue. We're talking a good 1-2 millimeter-thick buildup of carbon on the valve grooves on the piston head. Filthy.

So I hit it the piston with some steel wool and degreaser which got rid of most of it. I figured if I damaged the pistons, I'd just buy some new ones. I took my time and did it gently. It came out pretty well.

But before I go on to the heads and valves, I want to get some advice on cleaning products to use - I don't want to do any serious damage.

- First - is there anything i should get done professionally to clean the internals? - I'll get the externals soda-blasted later on, when everything else is done.
- For cleaning stuff myself - is steel wool and degreaser the way to go?
- I've also heard oven-cleaner can be good, but I'm worried it will be corrosive.
- Is there a special type of steel-wool that's best, or just regular old kitchen stuff?
- What about the exhaust ports in the head? It's kind hard to get in there.
- What about soaking the head in degreaser?
- Is it worth cleaning my filthy valves, or just drop the cash for new ones?

Thanks in advance guys.
I'm thinking of starting a thread for the build, we're going cafe and it's my first project bike! Stay tuned.


Cheers
-A

Starting one myself just waiting some tools from mikes!

You can clean all the carbon out the head, ports, and off the pistons using paint stripper. It may take a couple applications. What little remains will be softened up enough so you can easily gently scrape it off without damaging the surfaces. The valves are very hard steel and once removed can be wire wheeled clean. Soda blasting is another way to remove the carbon and really works well.

Ammonia removes carbon well, especially when you are able to soak the surface. We use it to remove coking in aircraft turbines, which is usually caused by small fuel and oil leaks. Everything burns away except the solids, which creates the coking/carbon residue.

Can I soak the head with the valves still in. Into carb cleaner? Will it do damage? There is a good build up in there and would be impossible with out pulling everything out.

Thanks first to respond

You can, but don't doit. Disassemble, then decoke...