In Line Fuel Filter switch to Spin on style??

[clintedwards]

I have a 2003 22VE with a Mercruiser 350. I have used the boat 2 times this summer with no problems. On the third outing, it would bog down over 2800 RPMs after 20-25 seconds under power. I can start from dead stop and accelerate normally and boats performs flawlessly for 20-25 seconds and then it stammers like its needing fuel. My thought is that the fuel water separator fills with fuel at low rpm but uses more than is being replenished, therefore it bogs. When I back down the throttle to 2700RPM the boat does fine without issue. Twin batteries fully charged, 13+v on gauge. After replacing filters, I will check fuel rail pressure.

Starting with least expensive items first, I replaced the fuel water separator. But the in-line fuel filter, part number 35-864572, dealer wants $62!! Guy said it was a special filter and might help avoid vapor lock??

I then tried OReilly, AutoZone and Pepboys for the crossed filters ($8-12). Looks identical to auto in-line for 8.1 Chevy but the fittings are different. The Mercruiser uses metric threads?? Took the auto filters to Lowes for brass barb fittings and they don't fit?? Guy at Oreillys said to use inline with sight glass but I'm afraid the flow rate will be too low, also no way to solid mount. I'd like to make changes easier so that I don't have to take out the floor to change the filter.

Has anyone tried to add a spin-on style 10 micron fuel filter kit from West Marine?? Part number 9399478 "SIERRA 10 Micron Filter Kit for Fuel Injected Engines" The kit is only $42 with filter, replacements are $9. 3/8 in/out fittings should be plenty of flow. Your thoughts?

Are these the only two fuel filters for this motor? I have read that some boats have 3? Thanks for your help!

Clint

[whitlock87]

The filter that came with you engine does remove water, a stock filler from Auto zone will not.
If you are going to add an inline filter, I would still keep the stock filer / water separator installed. The new stock filter will help to catch dirt, the stock filler will still need to be changed out as the water separator part of it will go bad over time. Also did you try and find you stock filer on the net?

[clintedwards]

Talked to a guy who really sounds very knowledgeable about this subject. He said that the boat manufacturers always put an in-line filter coming out of the tank because they don't know which motor will be installed in the bay. Some engines do not have fuel/water separators therefore the in-line would be the only filter. Removing the in-line and using a barb splicer is his recommendation. He says that the 10 micron FWS is mounted before the fuel pumps and will catch everything. Thoughts?

[clintedwards]

Got out there to install the barb splicer...and what do you know? There is a pump before the FWS. Went to AutoZone and bought a universal 3/8" in/out clear filter. For $4 i bought 2. Now cant get fuel primed to start. The fuel pump makes a weird noise, it makes a humming noaise then a ' clunk, clunk, clunk' noise. Bled the fuel rail and little fuel seeped out. I see the new inline filter has some gas in it but its not full. Do I continue to turn the key on and off to get it primed? Any ideas?

[dingleberry]

Do I continue to turn the key on and off to get it primed? Any ideas?

Normally, when replacing a fuel filter, that is exactly what you should do. Turn the key to the "on" position, wait 5-10 seconds, then turn off. Repeat several times.