i have heard there was a recall from merc on the 502 mags serpentine pulley system, but of course, i never got a notice, and never had a problem until the end of last year. I have under 200 hours on the boat still, so its really looks like brand new condition still.

My serpentine belt on one motor keeps slipping rearward at the tensioner pulley and it keeps freying the serpentine belt. I replaced the tensioner pulley and got a new belt, & it still did it, then i replaced the tensioner bracket, and another tensioner pully & belt, & it still did it, and im still having this issue, and going thru belts, and cleaning the dust off my motors every time i use the boat which really sucks, cuz im kind of a clean freak. So who knows what the fix is cuz it's really annoying me. I've checked all the accesories, all the bearings are fine in all of the components. i run a straight edge across them, they all line up just fine... Now that i have heard this was a common issue and that there was a recall, i want to hear who knows something about it, and who i call, or what i need to buy to stop this once and for all.... Thanks in advance.
Rob

ttt

I have yet to see a serpentine belt that did not leave residue. On a boat it slings all over the engine compartment and in a car there is more air flowing through and open area that allows the residue to escape.

there is a bushing that i replaced in the wheel that stopped it on mine

i'm guessing you mean the bushing in the tensioner? i've replaced the entire tensioner bracket assembly, which included the new tensioner and the bushing? Still looking for an answer? I use the boat once, and the belt totally freys, and is about to lose one of the four bands in it... HELP!!

ttt again...

We had problems with the serp belt on the race boat but this was not a 496. Anyhow we checked the allignment and installed a spacer on the water pump pulley and started running a gator belt. No problems since. Check your allignment. Check for burrs or rust on the pulleys and switch to a gator belt. Dave

Ditto Dave!!

Julie

ahh finally some replies, thanks! It's a 502Mag EFI, but the point i'm at it leading me to think the tensioner pulley needs to go rearward about 1/8"-3/16" which means i need to take the bracket off and machine that much off of the back side of the bracket where it mounts to the block... the pulley doesnt have much clearance room to move rearward on the bracket by shortening the spacer, so i will have to modify the bracket.

What a P.I.T.A. this belt thing is!!!

ok, i got my answer... In January of 2000 Mercury put out a parts bulleten for all V6 & V8 sterndrive engines with a serpentine belt. It's Bulleten 98-1 that was for the power steering pulley to go from a 4 3/4"dia plastic pulley, to 5-3/4" dia. metal pulley. it says to order a belt/pulley kit... Bigger pulley, & a longer belt... Problem solved, and now some archive reference for the future...