I recieved a piston for my Husky 55 today and am going to replace the old one because it was ran lean. Piston is shot but the cylinder is only very lightly scored. How should I prep the cylinder for the new piston and rings? Or do I even have to?
Most of the time the scoring that you feel is aluminum transfer from the piston. I use muriatic acid to remove the aluminum from the cylinder wall. I apply it with a Qtip only to the area that is scored and let it sit for a few minutes. Then rinse it with a spray bottle of warm soapy water. Wet sand with 340 grit and re-apply the acid if needed, sometimes it takes 3 or 4 attempts to get it all removed. Some folks here have had success with oven cleaner as it will eat aluminum also but muriatic acid can be had pretty easy. I buy mine at my local Ace Hardware as it's used for cleaning concrete, etc.
You should be able to get it at Lowe's. i had a friend that had a pressure washing business, he used it to clean concrete as well, and this is where he would get it.
Any Hardware store should stock hydrochloric acid/HCl (muriatic acid in the US)
They all do here.
Don't spray anything caustic or acidic around if you want the rest of the cylinder to stay as is, as Steve said use a cotton bud where it's needed.
I wouldn't hone either, Nikasil and chrome cylinders need specific stones, all you'll do with the common type ball hone is knock the top off the already honed surface and you stand a good chance at buggering the oil retaining ability of it.
Any Hardware store should stock hydrochloric acid/HCl (muriatic acid in the US)
They all do here.
Don't spray anything caustic or acidic around if you want the rest of the cylinder to stay as is, as Steve said use a cotton bud where it's needed.
I wouldn't hone either, Nikasil and chrome cylinders need specific stones, all you'll do with the common type ball hone is knock the top off the already honed surface and you stand a good chance at buggering the oil retaining ability of it.
I wouldn't hone either, Nikasil and chrome cylinders need specific stones, all you'll do with the common type ball hone is knock the top off the already honed surface and you stand a good chance at buggering the oil retaining ability of it.
don't use muriatic acid anywhere close to aluminum. it will destroy aluminum in a hurry. muriatic acid is gentle on steel and will take off rust nicely. but will destroy aluminum.
Sorry to threadjack, but this is very timely as I about to put new rings in a MS390 (no scoring, just tired). Does the above advice apply?
Also, many mechanics use a ball hone on cylinders before reassembling during a top-end rebuild. Ball hones are used to create fine oil retention paths on cast iron cylinders. On Nikasil cylinders, however, a ball hone won't do this. Instead, a ball hone will knock the Silicon Carbide peaks from the coating which wrecks the surface's oil retention capability. Ball hones are a bad idea for use on Nikasil coatings.
Which is why you use it to remove aluminium piston pickup from the bore, and why i said not to spray it around.
why use muriatic acid at all?
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