I recently took my beta-14 on a shakedown cruise and had erratic running issues, with symptoms of fuel-starvation/air infiltration.
I was suspicious of my Racor filter, as it had suffered from some corrosion from salt water, and I suspected that there was a small leak somewhere (no evidence of fuel leakage from the filter, or elsewhere, but it is my understanding that air can get in even when fuel cannot get out).
Symptoms: typically, a slight drop in RPM, then a greater drop, often running through a sequence of RPM oscillations, sometimes culminating in stalling. Frequency and severity of the problem increased over several days.
I completely disassembled the filter unit in the field, put new teflon tape on the hose couplings, all to no avail. Finally, at the end of the trip, I took the filter out of the fuel loop entirely, and the engine ran fine for 5-6 hours, and then started in on a similar cycle.
Now home, I will replace the Racor filter unit, replace the engine-block fuel filter, and hook it all back together.
The length of the fuel line (all flexible 5/16 ID, fuel rated hose, properly supported) is 6 feet or less from tank to Racor.
The length of the fuel line from Racor to engine fuel lift pump is 2 feet
The bottom of the fuel tank is approximately 12 inches above the lift pump, and the top of the tank draw tube is about 24 inches above the lift pump.
My questions are:
1. What size/capacity should my new Racor filter unit be?
2. Am I likely to have issues with possible fuel starvation issues because of the additional resistance in the fuel line of the Racor filter unit, and what are your recommendations for remedying them?
3. Do you recommend installation of a vacuum gauge to monitor filter resistance, and if so, where should it be installed in the fuel line?
thanks for your help
stu
PS: the size of the filter in use is 10 microns... would a 30 micron filter reduce the resistance in the fuel line?
-- Edited by StuartWeibel on Wednesday 23rd of August 2017 08:11:57 PM
You are fine with either a 10 or a 30 micron element in the Racor.
Although the smallest Racor is more than adequate for your engine, I would recommend going up to the 500FG. This unit is a bit more expensive than the R12 but is very easy to service as the elements load from the top. Thus, if you have a shut off valve, you can open the top, change the element and refit the top without losing any prime or needing to re-bleed the system. This makes for a very quick filter change and the elements are very cheap compared to the spin on elements used for the R12.
I think I found the problem... an intermittently clogged pickup tube. Cleaned the tank, and all seems to run fine now.
I took your advice and installed a 500 FG... I'm happy to have the additional margin of protection, and yes, the filters are very much easier to replace.
Thanks again for your assistance. I am cautiously optimistic that all the installation issues for my Beta-14 are now resolved.
