Cool Fuel 2
 

1999 502 MPI Mag, I found the black plastic cover for the cool fuel laying in the bilge and was able to reach it, question is where is this located on the engine ? Can boat be run with out this cover?

Under the port side motor mount, good luck......:D

Seems to be an impossible task, what about running with out the cover on, will the fuel heat to much or does the cover not insulate much?

It just snaps on if the clips are not broke, not sure what boat you have but Im sure it could be done, small guy 20 bucks, Im sure there's plenty running around without them but Merc put it on for a reason

No issue with it not being there

The boat is a 1999 Donzi 33ZX with 502"s, Cover looks ok don't see any broke on it. I sure can't get my big butt in that area so I'll try to find someone that might be able to reach it.
It's just weird that I found it after removing shrink wrap and de-winterizing boat unless mechanic that pulled the blue plugs for winterizing the motors knocked it somehow. Mercruiser
lists the part as an insulator cover but its just plastic but it must insulate a little some how?

It sets real close to the block drain on the port side so it could of been knocked off........starboard side is more difficult than port

Mechanic pulled it off to drain cool fuel , blue plug. Probably didn't get it snapped back on correctly

I'll give the mechanic a call to see if he remembers and could come by and re-install it. Thanks for that information about drain plug on the cool fuel, I didn't know that.
So it should be ok to run the boat with out it for now, till weather gets real hot?

I had a 2000 33 outlaw 502 mag cool fuel and it didnt have a blue drain plugs

If it doesn't have the drain plug not sure why it would fall off after being winterized?

Item 11 it blue plug and the black box is decoration, has no functional purpose
https://www.mercruiserparts.com/bam/...1912/4854/100\

I wouldn’t even worry about it! I run mine without the cover and no issues whatsoever!

If we can reattach it we will, if not I'll run it with out it. Plan on pulling motors next year so it might have to wait till then for it to be put back on.
Thank for the help on this it was driving me nuts.

As stated, imo the cover is just a decoration. I ran my 2000 MPI's for 20 years w/o the covers till I upgraded the pumps when I did a full rebuild.

Finally ran the boat a few days ago and boat ran good for the first 40 minutes then starboard motor started stuttering and didn't want to go over 2500 rpm's, slowed down to idle to check everything'
all gauges were fine motor idled ok nothing visibly wrong. Got back on plane and all was good for about 10 minutes the it started acting up again' keep boat at 2500 rpm's and it ran fine, I don't think
this has anything to do with the cover so I'll have to start checking I guess for fuel or electronic issue?

Getting hot your fuel pump may act and give less pressure
had that problem years ago.

Weak fuel pump or restriction in fuel line Fuel line collapsing, antisiphone valve, fuel filter
Put a fuel pressure gauge on the rail and watch

Definitely will check fuel pressure and also going to do tune up on both motors hopefully this week if work doesn't get in the way , and see what happens.

Exactly what my 99 500EFI's would do until I quit running fuel with ethanol and kept the blower on when the engines were running. That was three years ago when I bought the boat. Been running rec fuel since then without any issues.

Wow, I ran non ethanol fuel all last year with no issues till near the end of the season and put about 50 gallons of ethanol fuel in and my wife just reminded me that the last run of the year we thought it was sputtering then. I did treat the fuel before winterization.
Only 1 motor seems to be sputtering though, but something else to look into.

Id pull all the injectors and send them to ( Articfreinds ) Smitty on here, he'll get them tuned up and flowing correctly

Definitely something to look into, not sure how to remove them though? Would plenum have to be removed?

Yes, remove plenum to gain access to rail.
In most cases but not ll, the rail is removed from injectors from the rail on one side first before rail lifts off. To go back in install injectors in intake on one side and rail on other. It's in the manual

Finally got around to do basic tune up, plugs and wires, distributor caps and rotors, coils, IAC and new gasket sets for plenum. Started both engines ran a computer scan check no codes all seemed fine except 1 engines sounded like it was sucking a lot more air than the other
engine, Took boat out for test run and it ran very good thru idle and up on plane, stopped and opened hatch to check things out all looked good just the 1 engine with the air sucking sound, Any ideas as to what to look at?

Finally got around to do basic tune up, plugs and wires, distributor caps and rotors, coils, IAC and new gasket sets for plenum. Started both engines ran a computer scan check no codes all seemed fine except 1 engines sounded like it was sucking a lot more air than the other
engine, Took boat out for test run and it ran very good thru idle and up on plane, stopped and opened hatch to check things out all looked good just the 1 engine with the air sucking sound, Any ideas as to what to look at?