Ducati Monster Forum

Moto Board => Tech => Topic started by: electricpete on July 25, 2014, 02:08:11 PM

Title: 04 Monster 620 fuel pump- IT RUNS!! Part II
Post by: electricpete on July 25, 2014, 02:08:11 PM
For anyone who is curious, I'm pretty much answering my own questions, and this is what I found:
First, on the four-pin connector under the tank, the adjacent red and black wires are the pump leads.
Initially, when the pump wouldn't run, the resistance between them was unsteady but in the k -M ranges, obviously too high.
So, I pulled the pump (Jeeez! what a PITA!), took the screen off, sprayed a little SeaFoam Deep Creep into the inlet, and then, VERY GENTLY, with a small pick, reached in and turned the impeller.  I repeated this a couple of times, connected it to a 12Vdc source and, voila! it started.  I repeated this several times, only running it for 10-sec or so at a time, and watched its running current drop from about 2.5A to around 1.8A.  At the same time, it's static resistance dropped to a little over 1-ohm to under 1-ohm. Happy, happy, happy...
Went to NAPA to get some 30R10 hose. Yipes!! a one foot pre-cut length was $31!! Even the counter guy was shocked...
Anyway, I put everything back together (including a new 3032 filter), the bike started, and I'm a happy camper.
I can't account for the change in resistance unless this thing has an old-fashioned brushed DC motor and the commutator was dirty/oxidized...has anyone had one of these apart? Is that what it has, brushes and a commutator strip, or something else?
That's my story...hope someone finds this of use...

Peter
Title: Re: 04 Monster 620 fuel pump- IT RUNS!! Part II
Post by: tuxicle on July 25, 2014, 08:45:39 PM
It's possible that the plug through the flange that carries the wires has an intermittent failure. That would explain the high resistance which "fixed itself" afterwards. Mine was this way, got stranded a couple of times when the fuel pump quit on me while riding. At the time, Chris at CA-Cycleworks had a plug assembly for sale that would replace the stock one. Apparently this is no longer the case, but you might be able to find one used.

Here are a couple of relevant threads:

http://www.ducatimonsterforum.org/index.php?topic=61488.msg1136635 (http://www.ducatimonsterforum.org/index.php?topic=61488.msg1136635)

http://www.ducatimonsterforum.org/index.php?topic=60239.msg1117644 (http://www.ducatimonsterforum.org/index.php?topic=60239.msg1117644)

http://www.ducatimonsterforum.org/index.php?topic=61306.msg1131869 (http://www.ducatimonsterforum.org/index.php?topic=61306.msg1131869)
Title: Re: 04 Monster 620 fuel pump- IT RUNS!! Part II
Post by: electricpete on July 25, 2014, 09:30:34 PM
I measured the resistance at both the connector and right at the motor terminals and the readings agreed with each other, at least in magnitude.
Anyhow, thanks for the comments- this bike only has 88 miles on it and I'm pretty sure that just sitting has provided a breeding ground for various gremlins...

Peter
Title: Re: 04 Monster 620 fuel pump- IT RUNS!! Part II
Post by: CannedIce on September 17, 2014, 04:17:45 PM
I know this is a bit late, but Chris says there is a Ducati part number 51020032A that replaces just the wires and plug for about $139! Call your local Ducati dealer and order. Not much online when you search via Google :)