I saw this: http://www.mercurypartsexpress.com/us/rejuvenate-oil-473-ml-16-fl-oz-p240482.html I wonder if it would do more to clean the combustion chamber, rings, and valves of a 4 stroke engine when mixed with the fuel? [img]http://www.mercurypartsexpress.com/us/image.php?object_type=detailed&image_id=1001[/img] Rejuvenate Oil (473 mL 16 fl oz) * Price : $8.28 Rejuvenate was designed for military applications – to compensate for poor grade or mixed grade fuels. Its formulation includes a detergent that removes carbon build-up for easier starts, improved compression and restored horsepower. Superior lubrication and film strength protects against piston scuffing and extends engine life. Results can be realized within the first 2 to 10 engine hours, on your first tank. Rejuvenate is the ideal oil for any 2-cycle engine that has extended down time. Rejuvenate stabilizes fuel in premix applications**, and prevents rust from forming on internal engine components. Use Rejuvenate in all your 2-cycle engines: Outboard marine engines, ATVs, Go Karts, snowmobiles, personal watercraft (PWC), motorcycles, etc. It is recommended for use in air-cooled or liquid-cooled 2-cycle engines with oil injection systems or for pre-mix. **Rejuvenate stabilizes fuel in premix applications. Quicksilver Fuel System Treatment & Stabilizer - 858027K01 is recommended for engines where oil and gas are separate. Rejuvenate is recommended for classic carb and EFI 2-stroke outboards, and is not recommended for OptiMax.