This risks turning into an oil (opinion) thread so I will offer information and NO opinions. I assume in this that you are seeing some deposits and are wondering about cleaning products for that. I work at an oil change center and work with this stuff all day. I'd also like to think I'm well read on the subject. There are a variety of cleaners out there (specific products and do it alls like Seafoam) but they basically fall into two categories.
The lighter ones that are used at the store (at a healthy markup of course) are basically light base oil mixed with a larger portion of the regular oil detergent additives and work to dissolve sludge and deposits. We dump a 1\2 quart of this stuff in with the old oil and let it idle for 3 minutes. The oil is then drained and comes out noticeably darker than the initial oil on the dipstick. The bottle itself suggests allowing it to idle for 3-15 minutes. Next you have heavy kerosene based cleaners (diesel fuel ect.) these are much more aggressive will tend to loosen big chunks and send them floating around in the engine. There were quite a few older heavily sludged engines that seized because of this happening. Others had high mileage engines that without deposits lost compression and began to consume oil rapidly (needless to say their clueless owners ran them out of oil). We used these heavy cleaners in 80s-90s before corporate finally got tired of paying for new engines and switched to light duty cleaners. Flushing oil (SAE 0 weight) sold at auto parts stores are similar to the light cleaners except you replace the entire oil supply with this stuff and let it idle for 10-15 minutes and the effect is similar to a heavy cleaner. Seafoam is technically naphtha based but falls into this category as well. Keep in mind these things only tended to happen to heavily sludged or high mileage engines. If a motor only has a light sheen of deposits this can be a good option. But for motors like this http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1709990 and things somewhat less sludgy :) the only fail safe option is to open it up and clean it by hand. I hope this was helpful, Matt -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
