I purchased a Gravely 1238g which had been sitting inside for several years and had siezed engine.
Upon removing the muffler and head, I found quite a bit of corrosion around the valve and in the cylinder. Before I try to turn the engine, what should I do? Can the deposits be cleaned off, and how?The cylinder wall is covered with what appears to be something other than rust, and there is quite a bit of powder (like corrosion from battery posts) also.
Thanks,
Vic
I can't tell in the pics I looked up if it is an aluminum or cast block.
Is the powder white or steel rust color?
Either way, to start i usually dunk the block into some good ol fashion hot water and soap with a steel brush for bulky oxidation.
Dry it out and check the cylinder for pitting
Check the top of the cylinder for a ridge. If it does have one and its not too pronounced you can hone it. If not, a reaming the ridge or getting it bored my have to be the option. There's no need to get the cylinder bored out if it meets dia specs and there is no pitting. If there is any staining in the cylinder after you've cleaned it don't worry, it won't effect the operation and you should to crosshatch/hone it anyway so the stain will be gone.
The valves might be a bit trickier. Clean the valves using a wire wheel on bench grinder. Check both valves for pitting on the valve face and especially on the stem of the exhaust valve. The exhust valve takes a pile of heat and can deterioate pending how much the engine was run.
If the valves pass intitial inspection, take a look at the valve seats and look for pitting as well. Any pitting means replace the seats or service ( cutting or grinding) them. If the seats pass inspection, lap them with the valves (but make sure you check your tappet clearance when you reassemble).
Lets us know how you make out.
Rob