Fuel Filter Troubleshooting: Advice needed

[CTsalt12]

Ok so as you might've seen in  previous thread, I'm having a fuel flow issue.  Bulb is being sucked flat at higher RPM's, fuel vent is NOT the issue, next thing to check seems to be fuel filter (thank you Saltfly for order of operations suggestion).  It's a Sierra / Moeller type, no water bowl on the bottom, and the canister itself is Mercury brand, I haven't been able to find Mercury filter canisters to replace anywhere..

-Beyond checking contents of fuel filter canister for debris / water, how else can I check if the filter is halting flow of gas?  
It's probably time to replace the filter regardless, but do I have to replace the whole head unit, or just the canister?  

Additionally, Are there any tricks / Mcguyver methods for removing the filter canister without buying the special filter removal tool?  It's really stuck on there, I was going at it and couldn't get it to budge.

[mainefinn05]

You should only have to replace the filter.  You can try a belt/strap/rope and take a couple wraps around the filter then pull.  Imitates a filter wrench.  Something tacky would work best or maybe your local autoparts store loans out these kinds of tools.  Sounds to me like a partially plugged filter, allows draw at slower speeds but can't keep up with demands.  You can also lightly tap where the filter threads into the head unit at the same time you are trying to loosen it, this may help to break it free.

[Capt. Bob]

Here's what you need.
http://www.motorcycle-superstore.com/1/ ... =42469&kw={keyword}&gclid=CLvfyerN-7ECFeUWMgodKicAEg

[flounderpounder225]

these are at autozone, pretty versatile, and cheap.  http://www.autozone.com/autozone/access ... 72843_0_0_

those filters if not changed for a long time, will rust from the inside out, I have seen them develop a hole in the bottom from the rust inside, could very well be clogged.

[John Jones]

those filters if not changed for a long time, will rust from the inside out, I have seen them develop a hole in the bottom from the rust inside, could very well be clogged.

Just like this.

[flounderpounder225]

those filters if not changed for a long time, will rust from the inside out, I have seen them develop a hole in the bottom from the rust inside, could very well be clogged.

Just like this.

Nice training aids John...

[saltfly]

I reread your post. I don’t recommend doing this for more then a few min. But to check to see if the filter is the problem. Unhook the hoses from the filter head and put a double end barb connector in place of the filter and see if it runs ok. Also if you line from your tank is long enough. You can just hook it to the primer bulb.



Those pic's will show you what the in side can look like. So don’t even try to save the old filter. there are a number of companies that make filters that fit the merc. Head. Sierra, sea choice, quicksilver and  parker racor.  Are four. But just to point you in the right direction. The threaded whole in the Merc filter is smaller then the one on say Johnson. So you only have to read on the box of a new filter to find one that will fit your head or just open two boxes for different motors and look at the two holes. Also while you have the filter off. Remove the hoses on both ends of the head and blow air through the fitting. That will make sure their is nothing clogged in the head. It should be straight thru. This is also the time to blow air down the line back to the tank. Also make sure that when hooking up the hoses. You look on the top of your head. there are arrows pointing in the direction of flow. Also for the filter, make sure you get one that is a 10 micron filter and the flow rate is the right flow rate for your motor. I like a flow rate of 60 gph. To low a flow rate in the filter will cause a motor to loss gas on the high end. Motor will run but not at high rpms.

[John Jones]

Nice training aids John...

Yeah, sadly that was my filter on my flats boat.  Forgot to drain the filter and then let it sit for a couple of months.  That was never a problem with real gasoline but it doesn't work with ethanol.  The bad thing is that is a Racor with the water bowl.  There was a ton of water in there.

[saltfly]

I know this may sound a little excessive, but during the summer. I drain my racor filter , 2 times a month. During the winter, when the boat just sits. I take my racor off the head and put plastic over the head and tape it shut. Then in the spring I replace the filter. I don’t give rust time to build up. My head is sst. I know it’s a ouch, but  I think in the long run, its worth the money. When living in a humid area. You have to do everything you can because of that $%$# ethanol gas.

[Capt. Bob]

I know this may sound a little excessive, but during the summer. I drain my racor filter , 2 times a month. During the winter, when the boat just sits. I take my racor off the head and put plastic over the head and tape it shut. Then in the spring I replace the filter. I don’t give rust time to build up. My head is sst. I know it’s a ouch, but  I think in the long run, its worth the money. When living in a humid area. You have to do everything you can because of that $%$# ethanol gas.

Ethanol or not, they will rust and become wickedly hard to remove the longer they stay in place. This will also affect the clear bowl types so now you're fighting two items to remove. The procedure above sounds very familiar to me. Not bad at all if your boat sits for an extended period.  

JJ's photos, though extremely graphic and disturbing are reality at its ugliest.