Good afternoon,

First time posting on this forum, hopefuuly someone can answer some questions for me. I have an older 502, 29 scarab. have had this for 24 years. Most of that time I had a marina servicing the boat, only to find out they were not doing everything they should. So now, as the saying goes " if u want it done right, learn to do it yourself". My problem is, my mechanical pump that fed the vst had to be eliminated due to a broken drive lobe on the seawater pump. So i installed an inline electric pump and all new fuel lines and filters. The pump I installed was supposed to produce up to 75psi, but the gauge only reads max of 30psi Chinese Junk! I need about 37+- to run properly. The new pressure gauge is installed in the main fuel line after the pump & just before the fuel rail. At low speed, low rpm the boat will run ok. Once I get to about 300orpm the engine drops down in speed and rpm. it does not stall and once the throtte is pulled back it will recover and run at low speed. Feels as though it is starving for fuel. My first question is, the regulator on the end of the fuel rail, is it a fuel pressure reg or a pressure dampner, I have seen it described both ways. it is integral to the fuel rail so it cannot be eliminated. 2nd question, If it is a fuel press reg, can I install an adjustable regulator after the pump but ahead of the fuel rial. 3rd question, can anyone point me towards a good, reliable american made inline pump capable of 50+- psi and 40+gph. I have researched what I can find and all seem to have issues. Areomotive A1000 says it is made in china.

The vs tank has been removed and all new fuel lines installed with 100 micron prefilter and 10 micron post filter. New spark plugs and wires. new distributor cap and rotor. New quicksilver regulator on the end of the fuel rail w/ new vacumm line. New return line back to tank from return port on fuel rail. New fuel pump relay and several new sensors over the last couple of years. Any and all help will be appreciated.

I think the 10 micron is supposed to go before the fuel pump. The 100 micron is too restrictive it hurts the pump. Someone with more knowledge will chime in and verify but that's what I've heard.

Thanks for the input, but everything I have read and researched says the 100 should go before the pump. I will wait to see if anyone else has input. I have been known to be wrong before. Thanks for the help.

Not sure how or where you installed the new pump. My understanding about most electric inline fuel pumps is that they don't like to "lift" fuel out from the tank. Gravity fed is preferred or required. Factory fuel tanks draw from the bottom of the tank but through a line where the "out" is at the top of the tank. This way if there is a problem the fuel tank doesn't drain into the bilge. The pump you installed may not like the 18 to 24" vertical draw in your existing tank which may be the limiting factor.

Id get rid of the stock regulator and get an Aeromotive mount the gauge on it at the end of the fuel rail then your return comes off the reg back to the filter head or tank..... Ive been running their pumps and regulators for years without any issues, their office is about 30 min from me here in KC

Thanks for the input. The pump is mounted below the fuel tank so it is gravity fed. I just again researched several places for positioning the filters and all recommend between 75 and 150 micron prefilters. The problem is not fuel getting to the pump it is fuel & pressure getting from the pump to the rail.

ax I said in my original post, the oem reg is an integral part of the fuel rail. Due it s design it cannot be removed or blocked off. The design of this rail is is with the return port on top and the feed port on the bottom. if this regulator was removed there would be no path for fuel flow as far as I can see. If some one has done this I would be interested how it was done. I had tried this originally and found it stop fuel flow. From what I have seen so far, it appears that I my just have a pump that does not put out what the information says, but then again, it is from china. I always though chinese junk was the name of the type of boats they use, now i know it is most everything that comes from china. Thanks for the input, we can all learn from each other.

I have poor math skills....

Boy was I completely off on that. You have those filters correct. I'll just stay in my lane from now on. Good luck with your project

Quick heads up: You have your microns vs restriction backwards.
100 micron is much larger than 10, therefore 10 micron more restrictive then 100, assuming all else same between filters.

100 micron before pump is usually suggested.