I was looking through the owners manual of my 1999 M900 today and noticed that there should be a vacuum-operated fuel pump mounted on the right side of the frame, I don't have one! The feed line from the fuel tank goes directly into the carburetors. I bought the bike as a project bike about a week ago, I was able to ride it from the sellers place to my home (about 30 miles) with a few hiccups, but overall OK.
Anyone know the story on this? Was removing the fuel pump a mod for this bike? Based on what I've found thus far, the previous owner had no idea what he was doing and should not be allowed near a motorcycle.
If the fuel pump is eliminated you will have greatly reduced cruising range since the carb inlets are mounted higher than the bottom of the tank. There may be an electric pump mounted somewhere.
Is this what you are referring to?
(https://lh5.googleusercontent.com/-fGYz_KESfbY/Tv0b0yHQBFI/AAAAAAAAAIY/zDZNiRlQAEs/s400/vacfuelpump.JPG)
I know that replacing the vac petcock is a good mod, since they are prone to failure. But, the vacuum pump is supposed to be a pretty good piece.
So, you basically now have a gravity fed system...which means you can't use as much fuel out of your tank as if you had a pump. There might also be fuel starvation issues with high load on the engine.
The previous owner seemed to take the stance that if something broke or he didn't know how to fix something, remove it. Since the vacuum petcock is gone, I will be installing an inline fuel shut off valve in case I ever need to remove the tank. Also found out that my low fuel sensor had the wires ripped off, spent about 3 hours trying to find the cut wires, and have given up the fight. The PO was a MORON!
I've checked on eBay and Ducati forums and haven't been able to locate a frame mounted fuel pump, you guys have any ideas?
Howie, I like your idea of running an electric fuel pump instead of the OEM vacuum operated one. I've chedk on eBay and found 12V electric fuel pumps for about $40. The pump supplies 5-9 psi which should be plenty for my application, though I would prefer to lower the pressure to what the factory pump puts out so I don't blow any seals in the carburetors.
Regarding the fittings on the tank, I have a feed, drain, and bleed. Does anyone know what function the "bleed" fitting performs? If I am to use the electric fuel pump, my plan is to cap off the bleed fitting and use only the drain and feed fittings.
you might need a return.
Actually, I didn't recommend installing one, though it is a good idea. I said look and see if there is one in line. 5-9 PSI is high and could cause flooding. I think you would want 3 PSI, not sure.
Does the bottom of your tank look like this?
(http://i298.photobucket.com/albums/mm276/hlep2890/bike/IMG_0207-1.jpg)
The feed is clear. Where the factory got drain and bleed from is beyond me, but one is overflow and the other is vent, assuming your tank is stock. They can be joined, assuming your bike has no charcoal canister. Here is a thread on said canister http://www.ducatimonsterforum.org/index.php?topic=3446.0 (http://www.ducatimonsterforum.org/index.php?topic=3446.0)
If you go with a vacuum pump, the advantage being not needing to run electrics, you will need add a fuel shut off. The bike came from the factory with a vacuum operated shut off (circled)
May of us, including me went manual
(http://i298.photobucket.com/albums/mm276/hlep2890/bike/IMG_0422.jpg)
You can use an electric pump that delivers about 3-4 psi safely without a pressure regulator or return.
Howie, thanks for your post, it was very helpful. I have decided to abandon the electric fuel pump in favor of an aftermarket vacuum pump. I also don't understand what the "bleed" line is for, I will join the "bleed" and "drain" tubes as I have removed the charcoal canister.
Some searching on eBay lead me to this:
http://www.ebay.com/itm/Vacuum-Pulsed-Fuel-Pump-Clone-Go-Kart-Racing-/310362084226?pt=Go_Karts&vxp=mtr&hash=item4843059382 (http://www.ebay.com/itm/Vacuum-Pulsed-Fuel-Pump-Clone-Go-Kart-Racing-/310362084226?pt=Go_Karts&vxp=mtr&hash=item4843059382)
The way I look at it, the carburetors are expecting very low fuel pressure due to the float needles. They are probably not designed to handle more than 1 or 2 psi before they start leaking by. Since all vacuum pumps work on the same principle, I would mount this go-kart vacuum fuel pump somewhere on the frame and run it the way the OEM pump would have run which is off the vacuum ports on the intake manifolds.
$125 for a used Ducati pump, I THINK NOT!
Quote from: J-Speed Inc. on January 02, 2012, 06:23:47 PM
$125 for a used Ducati pump, I THINK NOT!
Psst...
http://www.ebay.com/itm/2000-Ducati-Monster-Dark-M-750-Vent-Valve-Vacuum-Breather-Second-Assy-/120799762785?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item1c203a1961#ht_500wt_717 (http://www.ebay.com/itm/2000-Ducati-Monster-Dark-M-750-Vent-Valve-Vacuum-Breather-Second-Assy-/120799762785?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item1c203a1961#ht_500wt_717)
Looks similar
Quote from: Dellikose on January 02, 2012, 07:29:16 PM
Psst...
http://www.ebay.com/itm/2000-Ducati-Monster-Dark-M-750-Vent-Valve-Vacuum-Breather-Second-Assy-/120799762785?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item1c203a1961#ht_500wt_717 (http://www.ebay.com/itm/2000-Ducati-Monster-Dark-M-750-Vent-Valve-Vacuum-Breather-Second-Assy-/120799762785?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item1c203a1961#ht_500wt_717)
Looks similar
Funny name for a fuel pump. Yes, that is the OEM pump.
What I found for $125 was the OEM fuel filter, petcock, and pump. I think my $16 go-kart vacuum fuel pump should work just as well as the OEM Ducati one, with half the price. Once I receive the pump and install it, I'll be sure to post the details for anyone else who may experience this problem.
I have had one Monster in the shop with an alternate fuel pump that suffered fuel starvation issues. It ran this pump:
(http://lh6.googleusercontent.com/public/QZ0dJGYtltKxtCSiy1wpRhiGBJG-Wm2cTAGJ5DmNOPDljZ-_vdst6n8_8UDZzQS5Pm1VUjtRwZMWDhH_IQIUm_K2jWaLBKEmNGsqx8Zcba0ybI2Ri9GjxjYhmdd858Vws0-Rku7mLV_0nbZds5H9j7IKyLFqUp9azqFxRXNIRqx7)
which is a commonly used alternative.
I've had best luck with rebuilding OE units (the kit is CHEAP from Sudco).
QuoteI've had best luck with rebuilding OE units (the kit is CHEAP from Sudco).
J Speed Inc. does not have one to rebuild.
Yep on the Sudco. It is a genuine Mikuni kit. DO NOT buy the Winderosa kit unless you would like to eventually turn your vertical cylinder into a giant fuel pump (requires removal of spark plug). Many have been successful with the rectangular pump. I wasn't, fuel starvation after a few weeks.
For my money I'm going with an electric when my factory pump fails.
http://www.yourautopartsstores.com/napa-auto-parts/product/carter-p74029-electric-fuel-pump/B000C01BAQ (http://www.yourautopartsstores.com/napa-auto-parts/product/carter-p74029-electric-fuel-pump/B000C01BAQ)
That will work...
On line reports have it at 2-3 psi on a car.
http://mgaguru.com/mgtech/fuel/fp201.htm (http://mgaguru.com/mgtech/fuel/fp201.htm)
That article lists several pumps that should work.
The OEM hex pump has excellent flow rates way above the rectangle pump's, (which you can witness with clear lines). I went back to it to supply pumper FCRs. I didn't measure it, I could see it. I'd use the rectangle pump in a 600 or 750 with CV carbs though.
It's interesting that even the stock electric pump in a carbed SS/SL has a return line. Though it didn't stop my Superlight's 39 FCRs flooding when crap got past the filter.. What PSI are they rated at, 3-4?
no pressure will be safe if the needle has junk holding it open.
I wonder what keeps the rectangle-shaped pump from not supplying enough fuel to the carbs. It must be a difference in the surface area of the diaphragm or maybe it's sensitivity to vacuum pressure. It could also be how it was mounted in the bike that had starvation issues, if it was installed with much longer fuel lines than factory, that could cause a drop in pressure and volume due to restriction.
Even at 2-3 psi, I can see an electric fuel pump easily overcoming the pressure of the floats holding the needle valve closed which would cause the carbs to flood fuel everywhere. All the pump has to do is supply enough fuel volume to keep the float bowls full of fuel, nothing else. Also, I'm sure Ducati had the technology to put an electric fuel pump in the bike if they wanted to, but chose a vacuum pump, I wonder why?
When I get the pump and the rest of the parts I'm waiting for to put the engine back together, I'll let everyone know how it goes.
The SS models had a low pressure electric pump.
I believe that vacuum pump was cheaper so Ducati used it on their entry level bike.
From experience 3 psi is not enough to overcome a float needle in good condition.
Quote from: J-Speed Inc. on January 04, 2012, 09:27:17 AM
Also, I'm sure Ducati had the technology to put an electric fuel pump in the bike if they wanted to, but chose a vacuum pump, I wonder why?
Quote from: ducpainter on January 04, 2012, 09:30:50 AM
The SS models had a low pressure electric pump.
I believe that vacuum pump was cheaper so Ducati used it on their entry level bike.
$$$ and the other issue that older Ducati's were overcoming was the electrical system on the bike was not sufficient for itself long term ( ie:regulator/rectifier units) so putting more items of electrical draw on a system that was on the verge of being taxed as it was would have raised that failure rate up a good bit...
On a similar thread, the comparative flow rates at 3 psi were something like, 60+ liters and 15-16 liters an hour (roughly from memory).
The rectangle pump theoretically should handle a stock 900 with CV carbs on a road bike. Thats a tank an hour, really honkin'.
There's theory, then there's practice. In practice I've personally worked on one bike, and have heard of several others, that starved for fuel with the rectangular pump, but worked fine with the OE unit. I don't know the cause, but I suspect upstream conditions didn't allow the pump to flow at an optimal rate....but regardless, it didn't work with the replacement!
Yeah, theory aside, thats also been my experience.The stock pump's flow rate appears much greater, so I went back to it.
Lots of folk ran their bikes with the pump successfully for years. Mine was fine for about a month. My guess is once in a while a pump sneaks through that is not ethanol resistant, possibly "new old stock" or for a different market.
UPDATE: SHE RUNS!
After installing a new float, DynoJet jet kit, new clutch cover, K&N pod filters, new fuel and vent lines, new fuel pump, new plugs, and oil + filter change, she roared to life last night about 10pm (doubt the neighbors were as thrilled as I was/am).
Some things I noticed when doing a few short test runs around the neighborhood is that there is a slight stumble at low throttle. This might be due to the bike needing a carb sync or the mixture screws adjusted.
Also, the combination of the Arrow exhaust, pos filters, and the open clutch cover make this bike LOUD!
The speedo wasn't working, but I believe that is due to an issue with the speedo cable routing.
Couple more hours of tinkering and she should be mechanically sound. There's a Ducati meet up in Ft. Lauderdale, gonna check that out with my sweet "new" ride!
Quote from: J-Speed Inc. on February 01, 2012, 08:23:25 AM
Also, the combination of the Arrow exhaust, pos filters, and the open clutch cover make this bike LOUD!
The filters aren't
that bad. ;)
I'm glad that you finally got her going again. Rack up the miles! [Dolph]
Haha typo, that should have read POD filters :)
Gonna spend a few hours doing more tweaking and checking before I take her on another long journey. I'm very excited to take my first Duc for a ride!
Ok, posts such as these require pics! ;)
Took her for a 22 mile ride through Downtown Ft. Lauderdale on Friday with my friend following me in his car (haha, you know exactly why). She did well, just a few bouts with randomly raised idle speed. I richened the idle speed mixture screws and dropped the idle down a bit. Also passed a rain test, which I wasn't planning to do
South FL forecast shows lots of rain this week. Hoping I can find an hour or two to take her for a ride. Don't worry d#vi@nt, I'll take pictures [thumbsup]
Quote from: J-Speed Inc. on February 05, 2012, 06:44:35 AM
Took her for a 22 mile ride through Downtown Ft. Lauderdale on Friday with my friend following me in his car (haha, you know exactly why). She did well, just a few bouts with randomly raised idle speed. I richened the idle speed mixture screws and dropped the idle down a bit. Also passed a rain test, which I wasn't planning to do
South FL forecast shows lots of rain this week. Hoping I can find an hour or two to take her for a ride. Don't worry d#vi@nt, I'll take pictures [thumbsup]
If the idle continues to hang and you have the idle speed down around 1100-1200 rpm check synch again. [thumbsup]
Will do! Taking her to a local Ducati meet, I'll snap some pictures and post them here.
ducpainter, PM'd you.