Had the boat sitting at a marina for 5 weeks awaiting an engine rebuild and they must have left the cover off. It appears that vinyl is stained with small spots that on initial inspection look to be tar like. I have tried almost every product mentioned on here. The stains now appear to be a left over orange residue. Any and all ideas will be tried. Products tried so far include:

simple green
soft scrub
isopropyl alcohol
westleys bleach white
clorox scrub
Maguire vinyl cleaner
scrubbing bubbles
more that I can't recall!

HELP HELP HELP HELP!

Goof Off worked great for me. After you use it use a high grade vinyl protectant.

26ZX Donzi, I had the same problem at LOTO last year after I blew a head gasket and the boat sat around for 5 days with the cover on. It was bugs that crawled under the cover that got cooked when the sun hit it. I still have a few little left over orange residue spots that I wasn't able to get out, but I didn't try Goof Off like steelware is recommending.
Good luck, I hope it works!

Believe it or not, I've had great success using Sea Power Cleaner Wax for the really tough spots. Like steelware said, be sure to go back with a good vinyl protectant after using it.

Hey, Macklin and steelware.
What is a good vinyl protectant to use?

I really like the mequires cleaner/protector for protection. Some people swear by 303.

Heres what I have done with success. Use soft scub with bleach, dab it on the spots and let it sit for a while, use a small brush. You may have to do it a few times. And last, if everything else fails, use can use MEK, but remember, you can destroy it as easy as you can clean it with MEK. It is a solvent and actually melts the vinyl so you have to use a clean white cloth and just hit the stain lightly, one pass.

Good Luck

I've got the same problem but my spots were caused by someone leaving a rusty tool on the seat for awhile (my best guess). Nothing severe but they won't come out either. Any suggestions for that?

spray nine . diluted with water , i have been told that those small dots are spider's ****!

small dots are spider ****. at least that's what we think. i like to use soft scrub with bleach diluted with water to make a paste, i let it sit and do its work, then reapply as necessary. then 303 like hell. i use this same mixture on the deck (non-skid) of the scarab.

some times you can actually clean it with a orange the acid breaks dirt and grime.