Loss of RPM

glennd3 · May 18, 2019, 02:11:15 PM

Quote from: Ron Hill on May 18, 2019, 01:43:14 PM
Guys : I ran my M25XP engine with out a lift pump for over a year. I had wired the electric fuel pump to the blower instead of the ON pole of the ignition switch. We traveled from the Potomac to Key West and back like that - we did not travel like that with the engine in idle!!
I would periodically turn ON the blower and note if the RPM increased. It usually didn't - if it did I changed out the Racor filter and then the RPM remained the SAME!!

Jeff : If you have the Racor filter before the fuel pump you do not need the cylindrical fuel pump (with its filter in the cylinder). Buy the cube!!

A few thoughts

Ron that is a good story!

Jon W · May 18, 2019, 03:09:59 PM

The fuel system with a remote electric fuel pump should be tank -> inline shut-off -> Racor -> electric pump -> on engine filter -> engine regardless of type of remote electric fuel pump. FWIW the filter/strainer inside the cylindrical pump is 74U, AKA a rock catcher.

From my point of view if changing from cylindrical series to cube series, the important questions are do you have room for the different hose routing, do you want to do the work to make those changes, and if you carry a spare is it the cube series?

Jeff Tancock · May 18, 2019, 04:01:50 PM

I'm not set on the cube. I just want a reliable pump.
The local napa store has the posi- flow (610-1051) which I think is cylindrical in stock so leaning that way but am open to suggestions.

Stu Jackson · May 18, 2019, 09:03:51 PM

Quote from: Jeff Tancock on May 18, 2019, 04:01:50 PM
I'm not set on the cube. I just want a reliable pump.
The local napa store has the posi- flow (610-1051) which I think is cylindrical in stock so leaning that way but am open to suggestions.

The Napa plastic we"offered" on the forum was as a backup and an inexpensive choice; not necessarily a full time replacement. That may have not been clear on that thread from a decade ago. If you can get a cylindrical Facet, that's what I'd buy.

Roland Gendreau · May 19, 2019, 07:21:17 AM

See my post here

https://c34.org/bbs/index.php/topic,9874.msg75960.html#msg75960

The cheap pump lasted 3 years, then failed with the click, click still clicking.

I spent the money on the more expensive pump to replace it.

Jeff Tancock · May 20, 2019, 09:33:14 AM

So the more expensive would be the gold flow?
I read all those posts but its confusing as the different pumps are often referred to as "these pumps"or"those pumps".

Jon W · May 20, 2019, 11:50:15 AM

Hi Jeff, it is confusing. The best I've been able to figure out, there are three types of Facet electric fuels pumps talked about on this forum. The prices I give below are from an online supplier called Aircraft Spruce. NAPA and others prices are different and generally higher.

The cylindrical body version was originally called the "Facet Interruptor" and has been replaced by the one called "Facet Gold Flo Interruptor Type". "Facet Gold Flo Interruptor Type" PN's are either 476087E or 476459E. NAPA cross reference PN's are either 610-1074 or 610-1076 respectively. By the looks of mine, this is what was originally installed on my 1987 MK1 boat. It is the highest price at $79.95.

The plastic version is called the "Facet Posi Flo", NAPA PN 610-1051. It is not the same as the cylindrical body version above. The "Facet Posi-Flo" version is the lowest price at ~$34-$38, but apparently has limited durability.

The cube version is called the "Facet Cube". I think this is the version Ron Hill was referring to. It is the in between price at ~$40-$50. One example "Facet Cube" PN is 40100N for you to look up. This PN is for reference only, I haven't looked into the specifications to verify which "Facet Cube" PN is the right fit for our application.

Hope this helps.

kurt · May 20, 2019, 02:03:10 PM

I had a similar loss of RPM issue on my '88. I noticed that it was dumping unburnt fuel out of the exhaust which led me to believe that back pressure might be the issue and it was. The exhaust elbow had narrowed. Replaced the elbow and problem solved. I didn't see this ticked off as a check in thread so thought I'd bring it up.

Kurt

Ron Hill · May 20, 2019, 04:47:30 PM

Guys : I wrote a Mainsheet tech note article a few years back on the Facet electric fuel pumps. I had tracked down the manufacturer and talked to one of their engineers. Don't remember the part #s, but what was surprising is that the new cylindrical pump and one of the cube pumps had a major internal redesign - to digital.
Instead of contact points that opened and closed there was a circuit board that did that function, which was a vast improvement. The "ticking" heard in that new pump design was the mechanical pump working not the contacts opening & closing.

A few thoughts

Roland Gendreau · May 20, 2019, 06:23:08 PM

Jeff

Yes the more expensive pump referenced in my post link is the gold flow model, about $150.
That's the one I bought to replace the 610-6051 model that failed in 3 years.

Jon W · May 20, 2019, 06:33:55 PM

or you can buy it for $79.95 plus tax and shipping from Aircraft Spruce.

britinusa · May 21, 2019, 06:59:54 AM

Having read this I did not see the start sequence (although starting is not the only issue)

Anyhooo, our start procedure is:
Check / clean out - Raw Water filter
Raw Water valve open (we close it when we get back to the the dock)
Ignition Switch On
Blower On 30 seconds - Blower Off.
Throttle minimum - Gear Shift Neutral - Stop lever down
Glow Plug 20 seconds
Start Button - normally 2 seconds max

Did a complete engine harness rebuild in 2017/18 including all new Gauges (Tach, Temp, Fuel, Voltage and new Injectors, Tubes & Rebuilt Injector Pump.
We hit 6.4knots at 2100 rpm in still water if the prop and shaft are clean (cleaned every month by divers)

Paul

Stu Jackson · May 21, 2019, 05:10:40 PM

Jeff,

IIRC the Napa Replacement thread has a link to this helpful Facet pump discussion from Fleet 1 in San Francisco:

http://c34.org/bbs/index.php/topic,2515.0.html

See reply #11. I haven't compared this to what anyone else wrote in this thread.

Jeff Tancock · May 21, 2019, 09:04:12 PM

I found the Facet Gold Flo FEP 87SV at a local automotive supply chain (Princess Auto) today at a good price after struggling to find one online that was in stock in Canada. They had 2 on the shelf!
Go figure!
Will try the install tomorrow.
Fingers crossed after the boat really struggled to make it back to the dock Sunday

Jeff Tancock · May 22, 2019, 06:59:38 PM

Bought and installed the new fuel pump.
No change! Waste of time and money.
Thought I had the fix. Crap!!!
Pulled the air intake/filter thing and tried the engine. No Change.
Changed the Racor again. No change.
I also opened up the bleed valve on the engine at full throttle to make sure there was excess fuel. There was.
I can't think of what next. Only thing that I haven't done is checked the exhaust riser.
The exhaust water blows out vigorously so I doubt that is restricted. Any suggestions on how to check the riser given how awkward that would be?
Any other thoughts?
I'm desperate!