Fuel tank and pump, advice needed.

utopia · 26-01-2011, 08:35 PM

My Y2K, carby M750 has a steel tank and an external, vacuum driven fuel pump.
I'm looking for a spare tank to paint, and while I'm at it I was wondering whether I could replace the vacuum fuel pump with an electric one fitted inside the tank. Just for tidiness sake and maybe improved rear cylinder cooling.
I don't want a plastic tank, for various reasons.
I believe some early injection models used steel tanks, but I don't think the later, injection-type pump will do as I suspect its overpowered for my carb engine (though maybe a control valve would sort that...? ....that would be my second question).
However, I've noticed that some Ducati SS models with carb engines have a different type of fuel pump fitted inside the tank. This pump is installed on internal clips through the filler neck rather than fitting to a circular hole on the base of the tank. According to my haynes manual early, steel tanked injection monsters used the same system and used a pump which is visually the same as the carbed SS models.

Does anyone know if a steel tank from one of the early injection monsters with this type of internal fuel pump would fit my bike, and if so, would I need to replace the pump with one rated for a carb engine...or could I fit a different control valve to the injection pump...or might the whole combo just drop straight in, even...??

Alternatively, can anyone tell me how to access Ducati parts lists/specs/assembly-drawings.

Ta, very much.

26-01-2011, 08:48 PM

ummmmmm why bother if it works - aestetics ~:?

you can get the exploded parts diagrams of the ducati website as far back as 2001 or something

http://www.ducati.com/services/maintenance/index.do (spare parts catalogue)

its a vacuum fuel tap rather than a pump and is just another way to stop the fuel pissing all over the floor when the motor isn't running

I don't see why you cant do it though, id copy the carbed SS fuel lines

Dukedesmo · 26-01-2011, 09:18 PM

I have an early (steel) injection tank for my carby monster. The pump and filter clip inside (as on the SS) and I plan to use the injection pump by fitting a loop with a 'T' to the carbs but no pressure regulator. That way there won't be any real pressure and the excess fuel will simply recycle to the tank and not (I hope) swamp the carbs.

If it causes a problem, I'll get a carby SS pump but I'm confident it'll be OK.

26-01-2011, 09:28 PM

Quote:

Originally Posted by Dukedesmo

I have an early (steel) injection tank for my carby monster. The pump and filter clip inside (as on the SS) and I plan to use the injection pump by fitting a loop with a 'T' to the carbs but no pressure regulator. That way there won't be any real pressure and the excess fuel will simply recycle to the tank and not (I hope) swamp the carbs.

If it causes a problem, I'll get a carby SS pump but I'm confident it'll be OK.

that's exactly how the carby SS seems to work

Dukedesmo · 26-01-2011, 09:29 PM

Quote:

Originally Posted by Scotty

that's exactly how the carby SS seems to work

Maybe the pump's the same?, it looks the same right down to the 'teabag' filter...

utopia · 27-01-2011, 01:06 AM

Wow, thanks.
Thats a top-hole, numero uno, first class response....
......and exactly what I hoped I'd hear.

I hadn't really thought the pressure thing through very much, cos I also thought it would be possible to swap to a carby-type pump from the SS. Your system sounds like it should deliver the goods though. The only thing I can think might happen would be that the pump would constantly run too fast due to having no pressure to work against, and overheat. But the carby pumps do look the same, don't they ?

Do you know exactly what year your tank was made ? ....The tanks I've seen have the date stamped on the rear hinge bracket, or maybe there's a sticker, or part number on it...?
Also, is it possible to see the pump clips through the filler hole.
....I've been searching ebay, but identification is sometimes difficult.

The reason I've ended up wanting to get rid of the external vacuum pump is partly for the sake of tidiness (both practical and aesthetic), but it came about after I bought some carbon airscoops. I'd got them for a mixture of reasons...part pure aesthetic, part to try to keep the rain off the electrics around there, and part because of a possible improvement to rear cylinder cooling. BUT when I look down the right hand scoop there's a thing like a can of tuna right in the firing line. Since I'm looking for a spare tank anyway, ........

Thanks for the parts catalogue link. I think the info I need may come in around 2001, and/or it may be slightly earlier,....I haven't checked yet.

Incidentally, I was still thinking of using the vacuum fuel tap thats fitted to my model.

Thanks again.
Its my round.

Dukedesmo · 27-01-2011, 10:53 AM

My tank was from a 2000 M900ie 'Metallic', here are some pics;

Underside;

Pump clip as seen through filler hole:

Pump, sender & filter;

AFAIK these tanks were made in 2000/2001 for M900ie and are easily spotted by the fact that they are metal, have the large filler cap hole (to get your hands in for servicing) and 4 fuel line connections underneath (flow, return, breather & overflow).

As for the pump overheating, I doubt it as they run constantly anyway using the fuel to cool/lubricate it, and with no pressure build-up I would think it should be less stressed.

Of course the fuel will be swirling around the tank, which it wouldn't with the vacuum pump but I can't see what problem that would cause other than noise - and I seriously doubt I'll be able to hear it when the engine's running.

Other than lack of pressure regulator this is exactly how my 916 works and I've never had any problems with the fuel system on that in 13yrs.

Using a fuel tap isn't a good idea because if it's closed and the pump is pumping that will damage something and with a pumped system when the pump isn't running the fuel won't come out anyway as the outlet from pump and filter sits high in the tank, so you don't need a shut-off valve for when the engine's not running - I'll probably fit some in-line push fit connectors to the fuel lines, the kind that seal when released to make tank removal easier for maintenance/tinkering though.

utopia · 28-01-2011, 02:21 AM

My cup runneth over with helpful info.
Thanks again.

I'm having a slow ponder about the pump issue.
Also the tap issue.

....to be continued.

28-01-2011, 09:54 AM

umm, also from memory the carb tank and the IE tank are ever so slightly different shapes so that the cut out where the seat joins 'isn't quite right' you might also want to look for a matching seat unit to go with the tank

also looking at my S4 tank (that's injection) the fuel pump clip is in the middle of the tank and the tea bag filter has the nozzle in the middle

utopia · 28-01-2011, 12:41 PM

Yes, I was aware that there might be an issue with the fit of tank to seat, but I'm not too sure how many variants there are, or which bits go with which.
I've looked at a tank from a slightly older carby monster ('98) and the tank/seat recess was a slightly different shape to my original parts......the front, pointy bit of the seat has a larger radius (about like a £2 coin) on my original, Y2K parts, whereas the earlier parts had a much smaller radius (more like a 1/2p coin).
From what I've seen so far, I think the injection tanks also had the larger radius, so I'm hoping that my seat is the same, but I have yet to confirm that.

ps....just looked again at Capo's recent 'fuel system tech' post and, lo and behold, there is a picture of the pump and tank internals in question.
Also, from the same post, the pump in the injection system delivers fuel to a pressurised chamber (in this case the fuel delivery line) at 3bar, from which excess fuel is discharged back to tank via a pressure control valve. Hence the injection pump operates against a pressure of 3bar the whole time, as opposed to the carby system which presumeably has no control valve and operates at 1bar, ie atmospheric pressure.
This was the reason I was wondering if the injection type pump would run too fast and overheat, though I guess the system should still work unless or until the pump burns out.
I dunno whether this would be the case or not, but either way the pump from a carby system should avoid the problem, I would expect.

I'm still pondering.

Kato · 28-01-2011, 12:55 PM

Quote:

Originally Posted by Dukedesmo

I have an early (steel) injection tank for my carby monster. The pump and filter clip inside (as on the SS) and I plan to use the injection pump by fitting a loop with a 'T' to the carbs but no pressure regulator. That way there won't be any real pressure and the excess fuel will simply recycle to the tank and not (I hope) swamp the carbs.

If it causes a problem, I'll get a carby SS pump but I'm confident it'll be OK.

You need to be carefull here as I know you have those nice new FCR's which don't like anything over 3 psi and a standard Efi pump is designed to run at 3.5 bar thats 49.3 psi, the same will apply to Utopia's problem if an injection pump is used its going to result in a big puddle of expensive fuel on the floor.

28-01-2011, 01:06 PM

Quote:

Originally Posted by Scotty

umm, also from memory the carb tank and the IE tank are ever so slightly different shapes so that the cut out where the seat joins 'isn't quite right' you might also want to look for a matching seat unit to go with the tank

Don't I know it!! It isn't just different between carb and IE tanks but not all carb tanks are the same.........

I'm living with "seat mismatch" issue as it's preferable to the "leak enough petrol to BBQ you" issue..........

It's usually only picked up by the anoraks / trainspotters amongst us though...........

gary tompkins · 28-01-2011, 01:20 PM

Quote:

Originally Posted by Gordon H

Don't I know it!! It isn't just different between carb and IE tanks but not all carb tanks are the same.........

I'm living with "seat mismatch" issue as it's preferable to the "leak enough petrol to BBQ you" issue..........

It's usually only picked up by the anoraks / trainspotters amongst us though...........

Oh I don't know Gordon - even a blind man in a sack would be able to spot that

Maybe you should stick a couple of these on the tank? Could avoid loosing any small children or pet dogs in there.

http://www.zazzle.co.uk/mind_the_gap...95099998901813

[engage anorak mode]

The seat and tank shape changed around year 2000, and effected any carbed or EFI monsters made after that date. Only easy way to avoid gap problems is to fit matched tank/seat combinations, however installing late seats to early frames isn't as straight forward as swapping tanks. The rear frame section and seat latching arrangement changed as well, so it'll need a fair bit of fettling to sort out. Later tanks are easily identified by the shape and size of the knee cut-outs. These are much more rounded on the post Y2K design, where as early monsters have a sharper straight edge at the top. Seat cut-out indent is the less obvious change between the two.

[anorak mode off]

Dukedesmo · 28-01-2011, 01:26 PM

Quote:

Originally Posted by Kato

You need to be carefull here as I know you have those nice new FCR's which don't like anything over 3 psi and a standard Efi pump is designed to run at 3.5 bar thats 49.3 psi, the same will apply to Utopia's problem if an injection pump is used its going to result in a big puddle of expensive fuel on the floor.

Yes I'm aware it might be a problem but I was hoping that by pumping fuel through a loop with no restrictive pressure regulator and with only a take-off for the carbs that I might be OK as the pressure would all go back to the tank.

If not I'll get a carby SS pump, which I believe should fit as it looks very similar.

I could probably run gravity feed as the carbs are much lower than the standard Mikunis but the tank feed isn't best setup for it, so might cause fuel starvation when the level gets low? and I'd prefer to keep the filter in the tank.

28-01-2011, 01:38 PM

Quote:

Originally Posted by gary tompkins

Oh I don't know Gordon - even a blind man in a sack would be able to spot that

The seat and tank shape changed around year 2000, and effected any carbed or EFI monsters made after that date. Only easy way to avoid miss-match is to fit matched tank/seat combinations, however installing late seats to early frames isn't as straight forward as swapping tanks. The rear frame section and seat latching arrangement changed as well, so it'll need a fair bit of fettling to sort out.

Jeeeez, everyones a critic!!!!! Yep already looked into changing the seat over but in the great scheme of things and working on the basis that not everyone has such a keen eye for detail as the Hants / Wilts lot...... I'll live with the gap (well, till I get round to sorting out the original tank anyways)

Now, I wonder if the cans off a 750ss can be fitted to the 900..........

26-01-2011, 08:35 PM	#1
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,561	Fuel tank and pump, advice needed. My Y2K, carby M750 has a steel tank and an external, vacuum driven fuel pump. I'm looking for a spare tank to paint, and while I'm at it I was wondering whether I could replace the vacuum fuel pump with an electric one fitted inside the tank. Just for tidiness sake and maybe improved rear cylinder cooling. I don't want a plastic tank, for various reasons. I believe some early injection models used steel tanks, but I don't think the later, injection-type pump will do as I suspect its overpowered for my carb engine (though maybe a control valve would sort that...? ....that would be my second question). However, I've noticed that some Ducati SS models with carb engines have a different type of fuel pump fitted inside the tank. This pump is installed on internal clips through the filler neck rather than fitting to a circular hole on the base of the tank. According to my haynes manual early, steel tanked injection monsters used the same system and used a pump which is visually the same as the carbed SS models. Does anyone know if a steel tank from one of the early injection monsters with this type of internal fuel pump would fit my bike, and if so, would I need to replace the pump with one rated for a carb engine...or could I fit a different control valve to the injection pump...or might the whole combo just drop straight in, even...?? Alternatively, can anyone tell me how to access Ducati parts lists/specs/assembly-drawings. Ta, very much.

26-01-2011, 09:18 PM	#3
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,898	I have an early (steel) injection tank for my carby monster. The pump and filter clip inside (as on the SS) and I plan to use the injection pump by fitting a loop with a 'T' to the carbs but no pressure regulator. That way there won't be any real pressure and the excess fuel will simply recycle to the tank and not (I hope) swamp the carbs. If it causes a problem, I'll get a carby SS pump but I'm confident it'll be OK. __________________ M900, 916, LeMans II.

27-01-2011, 10:53 AM	#7
Dukedesmo Registered User Join Date: Sep 2010 Location: Leics Bike: M900 Posts: 2,898	My tank was from a 2000 M900ie 'Metallic', here are some pics; Underside; Pump clip as seen through filler hole: Pump, sender & filter; AFAIK these tanks were made in 2000/2001 for M900ie and are easily spotted by the fact that they are metal, have the large filler cap hole (to get your hands in for servicing) and 4 fuel line connections underneath (flow, return, breather & overflow). As for the pump overheating, I doubt it as they run constantly anyway using the fuel to cool/lubricate it, and with no pressure build-up I would think it should be less stressed. Of course the fuel will be swirling around the tank, which it wouldn't with the vacuum pump but I can't see what problem that would cause other than noise - and I seriously doubt I'll be able to hear it when the engine's running. Other than lack of pressure regulator this is exactly how my 916 works and I've never had any problems with the fuel system on that in 13yrs. Using a fuel tap isn't a good idea because if it's closed and the pump is pumping that will damage something and with a pumped system when the pump isn't running the fuel won't come out anyway as the outlet from pump and filter sits high in the tank, so you don't need a shut-off valve for when the engine's not running - I'll probably fit some in-line push fit connectors to the fuel lines, the kind that seal when released to make tank removal easier for maintenance/tinkering though. __________________ M900, 916, LeMans II.

26-01-2011, 08:48 PM	#2
Scotty Guest Posts: n/a	ummmmmm why bother if it works - aestetics ~:? you can get the exploded parts diagrams of the ducati website as far back as 2001 or something http://www.ducati.com/services/maintenance/index.do (spare parts catalogue) its a vacuum fuel tap rather than a pump and is just another way to stop the fuel pissing all over the floor when the motor isn't running I don't see why you cant do it though, id copy the carbed SS fuel lines

27-01-2011, 01:06 AM	#6
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,561	Wow, thanks. Thats a top-hole, numero uno, first class response.... ......and exactly what I hoped I'd hear. I hadn't really thought the pressure thing through very much, cos I also thought it would be possible to swap to a carby-type pump from the SS. Your system sounds like it should deliver the goods though. The only thing I can think might happen would be that the pump would constantly run too fast due to having no pressure to work against, and overheat. But the carby pumps do look the same, don't they ? Do you know exactly what year your tank was made ? ....The tanks I've seen have the date stamped on the rear hinge bracket, or maybe there's a sticker, or part number on it...? Also, is it possible to see the pump clips through the filler hole. ....I've been searching ebay, but identification is sometimes difficult. The reason I've ended up wanting to get rid of the external vacuum pump is partly for the sake of tidiness (both practical and aesthetic), but it came about after I bought some carbon airscoops. I'd got them for a mixture of reasons...part pure aesthetic, part to try to keep the rain off the electrics around there, and part because of a possible improvement to rear cylinder cooling. BUT when I look down the right hand scoop there's a thing like a can of tuna right in the firing line. Since I'm looking for a spare tank anyway, ........ Thanks for the parts catalogue link. I think the info I need may come in around 2001, and/or it may be slightly earlier,....I haven't checked yet. Incidentally, I was still thinking of using the vacuum fuel tap thats fitted to my model. Thanks again. Its my round.

28-01-2011, 02:21 AM	#8
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,561	My cup runneth over with helpful info. Thanks again. I'm having a slow ponder about the pump issue. Also the tap issue. ....to be continued.

28-01-2011, 09:54 AM	#9
Scotty Guest Posts: n/a	umm, also from memory the carb tank and the IE tank are ever so slightly different shapes so that the cut out where the seat joins 'isn't quite right' you might also want to look for a matching seat unit to go with the tank also looking at my S4 tank (that's injection) the fuel pump clip is in the middle of the tank and the tea bag filter has the nozzle in the middle

28-01-2011, 12:41 PM	#10
utopia No turn left unstoned Join Date: Jun 2010 Location: leicester Bike: M750 Posts: 4,561	Yes, I was aware that there might be an issue with the fit of tank to seat, but I'm not too sure how many variants there are, or which bits go with which. I've looked at a tank from a slightly older carby monster ('98) and the tank/seat recess was a slightly different shape to my original parts......the front, pointy bit of the seat has a larger radius (about like a £2 coin) on my original, Y2K parts, whereas the earlier parts had a much smaller radius (more like a 1/2p coin). From what I've seen so far, I think the injection tanks also had the larger radius, so I'm hoping that my seat is the same, but I have yet to confirm that. ps....just looked again at Capo's recent 'fuel system tech' post and, lo and behold, there is a picture of the pump and tank internals in question. Also, from the same post, the pump in the injection system delivers fuel to a pressurised chamber (in this case the fuel delivery line) at 3bar, from which excess fuel is discharged back to tank via a pressure control valve. Hence the injection pump operates against a pressure of 3bar the whole time, as opposed to the carby system which presumeably has no control valve and operates at 1bar, ie atmospheric pressure. This was the reason I was wondering if the injection type pump would run too fast and overheat, though I guess the system should still work unless or until the pump burns out. I dunno whether this would be the case or not, but either way the pump from a carby system should avoid the problem, I would expect. I'm still pondering.