RYDLYMEMarine Biodegradable Descaler - 1 Gallon

This stuff worked so well! My 50hp Honda outboard was having cooling issues and I thought it was going to have to be rebuilt which would have cost a fortune. I set up a 5 gallon bucket with a 800gpm pond pump, removed lower unit and pushed a 1/2" hose from pump onto the cooling water tube sticking out bottom of engine. Also used a 3/16" barbed fitting to extend the tell tale hose to bucket. Removed thermostat. Then taped a trash bag with the bottom cut off onto the engine and draped into bucket. Mixed Rydlyme 50/50 with water, and ran the pump for 3 hours. The water almost turned gray there was so much salt and junk in it! When I dumped the bucket there was a thick sediment in the bottom too. Flushed the engine really well with fresh water right away. We just took the boat out and it's like a new outboard! So happy!!

Best descaler out in the market

I was having serious over heating issues with my Yamaha 50hp outboard engine and the mechanic said it was the worst lime/calcium buildup he had ever seen in an outboard motor. He cleaned as much as he could but to no avail...still getting very hot. I ordered the rydlyme in hopes that I could resolve this issue because a new motor at this point is not possible due to about a year back order. I ordered 2 gallons and mixed at a 1:1 ratio, removed lower unit and went directly into the main water intake. I was amazed at the amount of debris that came out. I flushed a second time and more came out than the first time. I flushed a third and final time...and not much came out. 2 hour flushes followed by 15 min fresh water rinse. Engine looks new on the inside and best of all, no overheating issues. Runs like a new motor again. I would recommend rydlyme for a great internal cleaning to resolve issues and as a yearly maintenence step for prevention. I will be buying more at the end of each season. Amazing stuff.

I bought this because I manage 100 apartments and do the remodeling. We go through a lot of tub spouts and shower heads because they get blocked with deposits. The stuff we all know about at the hardware store doesn't do anything to remove the scale... This stuff eats and bubbles like mad while cleaning it all out and does it quickly. It can put a dark stain on metal so what I do is use painters blue/ green tape to cover the metal to protect it then put the part into the solution.

Did the job but wish it wasnt so expensive. I need to flush my motor again as this worked at about 85% clean

It works as advertised. Recirculated 4 hours in 1999 90hp 2 stroke outboard, was very surprised at the sediment when completed.

Stuff works awesome , as good as acid without the harshness or environmental concern

The product seems to clean well. The problem is the hose popped out of the bucket and stained my gel coat and Seadek. Be careful if you use it