cool fuel III interesting trouble

[Bt Doctur]

Got my hands on a unit that a shop had replaced because of a fuel problem. The unit was not cooling the fuel leading to some issues, running ,vapor lock, etc.
Shop replaced the cool fuel unit to restore service to the customer. I got it wanting to dissect it to see how it worked, What I found.
Filter was clean ,no debris
both the hi and low pressure pumps work correctly
upon checking the water cooling passages, they were blocked with sand/debris completely
Rodded with a control core cable, hose flow tested ,full flow thru the unit and the drain port restored
So, should you be experiencing a issue with your unit ,before spending that kind of cash to replace it ,try cleaning the water cooling passage out first and periodically remove the drain plug and let any accumulating things get flushed out
Have a Nice Day
Bt Doctur

 

[Bondo]

Ayuh,..... As always, Great info BD,.....

 

[Lou C]

I’d think that’s common on boats that often run in shallow water and here in the salt pond I wound not be surprised to find crud growing in there, as is common with moored boats with outdrives here. Every year you have to rod out the water intakes or else you’ll have a low water flow problem. In fact I had to remove the plastic screen in the lower unit that OMC used because I constantly had barnacles growing on it.

 

[muc]

The Cool Fuel III and Single Point Drain system have a bad reputation on the internet. I could never understand why, I worked for dealers that sold/serviced many of these and we had almost no problems. So I started asking other techs around the country and found that the ones that were seeing issues were also the ones that didn't winterize per MerCruisers requirements. They skipped either the flush and leave full PG antifreeze or running the Fuel Storage Mixture, sometimes both.
Makes me think that a lot of issues could be solved with normal maintenance.
And, yes boating in sandy, silty and dirty water needs maintenance more often.

 

[alldodge]

As Bondo says, air don't freeze

 

[muc]

As Bondo says, air don't freeze

Can't argue that on the older product. I winterized 100s of I/Os for $99.95 fog, drain, oil+filter, lower unit lube and grease. No antifreeze. No problems. Heck, we used compressed air to blow the sink water lines.
Then it the late 80s early 90s engines started to get more complicated and we had to adapt.

 

[alldodge]

Can't argue that on the older product. I winterized 100s of I/Os for $99.95 fog, drain, oil+filter, lower unit lube and grease. No antifreeze. No problems. Heck, we used compressed air to blow the sink water lines.
Then it the late 80s early 90s engines started to get more complicated and we had to adapt.

I honestly think your the smartest guy here, but if the average boater wants easy winterization yank the single point out by the roots and go back to 7 point

If you have a Gen 3 cool fuel and want to do easy fix prior to yaking the whole thing out, install a 10 mic canister filter prior to the Gen 3 and don't bother with the internal Gen 3 filter.