500EFI Pulley question.....

JETJOCK

New member
Out running my Scarab today and heading back into port I have an enigne alarm sound....starboard engine getting hot...I killed it and noticed the serpetine belt loose! (500EFI Blue Merc Racing engines)

The belt was fine, which I thought was odd....so upon closer inspection I noticed the pulley on the water pump was about to come off! All four allen head screws (actually only 3 were left--one is MIA) were loose as a goose, causing the tension to become loose on the belt--leading to to come off completely.

So I need to get to a Hardware store tomorrow and get some Allen head bolts--does anyone know the correct size off hand? I have two in my hand with washers.

Anything I need to do special when I bolt the pulley back on and replace the belt?

Again thanks in advance-I learn a lot on this forum!
 
Out running my Scarab today and heading back into port I have an enigne alarm sound....starboard engine getting hot...I killed it and noticed the serpetine belt loose! (500EFI Blue Merc Racing engines)

The belt was fine, which I thought was odd....so upon closer inspection I noticed the pulley on the water pump was about to come off! All four allen head screws (actually only 3 were left--one is MIA) were loose as a goose, causing the tension to become loose on the belt--leading to to come off completely.

So I need to get to a Hardware store tomorrow and get some Allen head bolts--does anyone know the correct size off hand? I have two in my hand with washers.

Anything I need to do special when I bolt the pulley back on and replace the belt?

Again thanks in advance-I learn a lot on this forum!

Lets hope u did not break the crank..i did twice and it looks just like u described it !!!! :eek:

If its not broken,,something else is wrong to shake them loose...out of balance !!!!
 
We looked at the pulley real close and I do not think the crank is broke....at least I hope not---just seems like the bolts were lose, I did replace the water pumps recently...about 10 hours ago or so.
 
We looked at the pulley real close and I do not think the crank is broke....at least I hope not---just seems like the bolts were lose, I did replace the water pumps recently...about 10 hours ago or so.

But there has to be a reason for the bolts to come loose !!!!!!

maybe the balancer is shot..thats why my crank broke ..thebolts did not come loose,but my crank broke in half even we where still able to get in to the dock at WOT.lol
 
I have two in my hand with washers.

Anything I need to do special when I bolt the pulley back on and replace the belt?

Again thanks in advance-I learn a lot on this forum!

I think they are 5/16 24? or 3/8 but there way they are fine thread. You have two in your hand you should be able to match them. You should loctite them in .
 
ahhh locktite...


I know we didn't use locktite when I changed the Seapump.....is it possible they just "got" loose...or is this a deeper issue?

I have had a great season with ZERO issues.....off to the hardware store and see if I can't fix this..


Thanks again guys....KEEP it coming!
 
:iagree:

But still ,,they don't come loose with out a reason !!!???

uneven torque?? for us mechanics its easier to uniformally torque bolts by feel without a torque wrench. not that its really needed for a pulley but.... If your not really into wrenchen than mabey you overtightened 1 or 2 of the bolts and left the other ones to loose?
 
Ok--I replaced the missing bolt in the pulley--I think they worked loose becuase they were not tightened properly. I noticed the belt was loose so I replaced it and everything is BACK TO NORMAL!

Couple of runs out to the bay and back and she is 100% again....best part is I wrenched on it myself with a little guidance along the way.


Thanks again for all the help.....this was an easy fix.
 
Mercury used to safety wire them on HP engines.. Not sure why they stopped. They are not the easiest things to tighten. I have a strap type wrench to hold pulleys without damaging them.

I am happy to hear you got it going on short order.
 
I think I will add this to my "preflight" duties, checking all the bolts and hoses on a regular basis.

Anyone have a part number handy to order some replacement belts? I might replace the other one as long as I have this fresh in mind.

the last one was in a bag titled "Quicksilver" and the part nmber is a little smudged.
 
As long as I am asking....

Where can I find the Pulley Bolts (stainless Steal with washers) the have the allen head on them and bolt the pulley (4 of them) The bolt is 5/16 fine thread.

Is there a good place to order this other then Mercruiser?

I need to replace ONE of them since it is not stainless....

THANKS-IN-ADVANCE

Randy
 
As long as I am asking....

Where can I find the Pulley Bolts (stainless Steal with washers) the have the allen head on them and bolt the pulley (4 of them) The bolt is 5/16 fine thread.

Is there a good place to order this other then Mercruiser?

I need to replace ONE of them since it is not stainless....

THANKS-IN-ADVANCE

Randy

www.mcmaster.com !!!!!!!!! has everything u need ..EVER !!!!!!! :cheers2:
 
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