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Discussion Starter · #1 ·
Hello,

I'm rebuilding a salvage '95 Ducati 900SS/CR. Its never run since salvaged and was in pretty bad shape. I've rebuilt the engine and put in high compression pistons. I also pulled out the stock fuel pump and put on an external pump. I hate those internal things. It has stock headers, but some funky slip ons that I can't figure out the make. I pulled off the air box and stuck foam filters on the stock Mikuni's. When I ran fuel to the carbs for the first time, they overflowed badly...not too surprising.

Anyway, I went to take the carbs off and I snapped the cheap plastic fuel line connector on the fuel line rail on the carbs. Ugh! I don't think that part is replaceable, but I'm going to check. I suspect it will be expensive, plus I need to get a rebuild kit for the carbs for a couple hundred.

So, this is my very long story about how I'm now thinking about just getting Keihin 41's. I suspect it won't be too much more, plus it sounds like a good idea with the open airfilters and high-compression pistons. I have a couple questions:

1. Do I still need the fuel pump, or do the carbs pull the gas? I've heard both.
2. Do you think I'm on the right path with the Keihins? That is, do you think I'm on the right path for the bike and for the money?

I don't have any specific plans for the bike, and I have other nicer Ducati's. I am thinking this could be an excellent track bike.

Thank you very much!
 

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yes you should.yes you do.(fuel pump)what external pump did you use? where did you mount it?
 

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Hello,

I'm rebuilding a salvage '95 Ducati 900SS/CR. Its never run since salvaged and was in pretty bad shape. I've rebuilt the engine and put in high compression pistons. I also pulled out the stock fuel pump and put on an external pump. I hate those internal things. It has stock headers, but some funky slip ons that I can't figure out the make. I pulled off the air box and stuck foam filters on the stock Mikuni's. When I ran fuel to the carbs for the first time, they overflowed badly...not too surprising.

Anyway, I went to take the carbs off and I snapped the cheap plastic fuel line connector on the fuel line rail on the carbs. Ugh! I don't think that part is replaceable, but I'm going to check. I suspect it will be expensive, plus I need to get a rebuild kit for the carbs for a couple hundred.

So, this is my very long story about how I'm now thinking about just getting Keihin 41's. I suspect it won't be too much more, plus it sounds like a good idea with the open airfilters and high-compression pistons. I have a couple questions:

1. Do I still need the fuel pump, or do the carbs pull the gas? I've heard both.
2. Do you think I'm on the right path with the Keihins? That is, do you think I'm on the right path for the bike and for the money?

I don't have any specific plans for the bike, and I have other nicer Ducati's. I am thinking this could be an excellent track bike.

Thank you very much!
The Keihin's are a good upgrade, particularly if you're going to keep the bike for some time, they work well and you'll find plenty of happy converts on here. On the down side they are a bit pricey at around $900 last time I looked and can be a bit abrupt in operation which doesn't make them ideal for around town use. Ultimately how you decide to use the bike will play a part in your final decision whether to go the Keihin way or not I imagine.

However, your Mikuni's aren't quite trash material yet - for less than $100 you can get them running OK, spend a little more (if required) and you can get them running sweetly.
The fuel inlet tee can be purchased from a Yamaha dealer or numerous online parts sites, I recently bought one from Wemoto in The UK (< link to their website, OEM part # search at bottom right of page) and along with two rubber seals that seal it to the carbs, all up they cost £21.00 including shipping to New Zealand for all 3 pieces!

Part numbers and Yamaha speak descriptions:
Tee: 3EN-14988-00-00 "Pipe, Starter Connecting"
Seals: 3EN-14997-00-00 "Seal"

Carb kits can be purchased off EBay or online parts sellers such as: Carb Kit Capital - Motorcycle Carb Parts (middle of page) for $20 upwards.

Your carbs are basically the same as fitted to early model Yamaha TDM850, XTZ750 and FZR1000. Obviously jets and needles etc are different but most everything else will fit including the float needle.
If you need the tiny o-rings on the pilot screws which are often damaged, worn out or missing, these don't seem to come with any of the kits I've seen, so it's either a trip to your local engineering supplier and search through their o-rings (remembering to get fuel resistant ones!) or you can buy them from Yamaha as a complete pilot screw set which gives you the pilot screw, spring, washer and o-ring. part number for that is 12R-14105-00-00, usually around $20 each.

If you need jet needles and/or emulsion tubes then Factory Pro is the place to go as they have uprated parts that don't wear like the standard Mikuni items:prodd09.html, Ducati 900ss/cr/sp Test Data by EC997a Eddy Current Dynamometer

Note that CV carburetors like those Mikuni's don't particularly like foam/pod filters and tend to run much better with an air box and panel filter (open top if you want a tiny bit more performance and much nicer intake noise).

Hope that helps with the decision making :D
 

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The Keihin 41s on individual Malossi short stacks is the way to go. Stronger performance than mounted together and you can then eliminate the fuel pump because the new position will result in a gravity feed setup. It worked really well on my '06 SS/SP.
 

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get the kit from Ca-cycle works has everything with it.
You wont regret the change and you dont need the elec fuel pump.
The FCR's have a throttle pump. :)

Keihin FCR 41 Carburetor Kit for Ducati SS | Fueling EFI / Carbs | Products | ca-cycleworks.com

Keihin FCR FAQ

BikeBoy.org - Ducati 900SS Carb model with Keihin FCR 39 and 41mm carbs
Ha ha, wrong! You will need a fuel pump if co joined on stock manifolds. "Throttle pump" is the accelerator pump function of the carbs which needs to be firstly feed by fuel via the fuel pump.
 

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My understanding is the stock carb position will only gravity feed about half the gas tank.

It requires a fuel pump to consume the remainder.

Bob
 

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Discussion Starter · #8 ·
Thank you all. Great information CS363! You've opened the idea of keeping the Mikuni's. I'll check into the parts and cost and then decide. I'll probably do the Keihins eventually, but I might make the mikuni's work just to get the darn bike running. I'll have to look for the fuel pump brand. I just did a search for the right flow and mounted it under the battery. My bike is turning into a bit of a frankenstein, but I'm hoping in the end it's a bit cleaner. I'm having a lot of fun with it. Thanks again...Ken
 

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Keihins are great, especially with HC pistons. Really wakes the bike up throughout the RPMs! Racked on stock manifolds do need fuel pump. Split single Keihins on short (Malossi) manifolds do not need a fuel pump. Stick with stock airbox (no pod filters) unless you go split single Keihins on short manifolds. It will run better.
 

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I think the stock header will need to be replaced if you want this to be an "excellent track bike". Lean angle/ground clearance is quite limited otherwise.
 

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The Keihin 41s on individual Malossi short stacks is the way to go. Stronger performance than mounted together and you can then eliminate the fuel pump because the new position will result in a gravity feed setup. It worked really well on my '06 SS/SP.
Ive been trying to find the Malossi manifolds for a while, as Ive been agonizing on whether to buy split or racked FCRs.

Anyone know where they are available? Are there other options?

Should I just buy the racked kit?

Thanks.
 

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My shop is installing my set of FCRs this week. He said racked FCRs do need a pump to feed from the whole tank.
The doesn't provide positive pressure just feed, and there's a return line for unused fuel.



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I think the stock header will need to be replaced if you want this to be an "excellent track bike". Lean angle/ground clearance is quite limited otherwise.
I know we're on the topic of Keihins, but since you brought this up...

Another option is to remove the stock header, cut out 3/4" of pipe on each side, and have the header re-welded.

I did this with my 944cc 900ss, and it worked well. Over 90hp with a basically stock header.
 

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Keihins are great, especially with HC pistons. Really wakes the bike up throughout the RPMs! Racked on stock manifolds do need fuel pump. Split single Keihins on short (Malossi) manifolds do not need a fuel pump. Stick with stock airbox (no pod filters) unless you go split single Keihins on short manifolds. It will run better.
This is exactly what I did including pod filters with the SS/SP pictured in my last post. It also had HC pistons, 944 kit, lightened flywheel, and mildly ported heads. Not done by BCM but lots of helpful advice and bought the parts there. Bruce and I had a discussion about the results (always dangerous having two Bruces (Bruci?) in a room) and he guessed it would make close to 90 hp at the rear wheel. In the end it was pretty damned quick, reliable and got great mpg. Only sold it because of a divorce.
 

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Ive been trying to find the Malossi manifolds for a while, as Ive been agonizing on whether to buy split or racked FCRs.

Anyone know where they are available? Are there other options?

Should I just buy the racked kit?

Thanks.
My friend Ben got the Malossi's but it was about 10 yrs. ago. You could give him a try at his shop...Motoconsult - Mansfield, CT
 

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Just to play devil's advocate, te stock mikunis can be super reliable as well. If you can find that little piece, properly tuned they can e a wonder.
Mine starts IMMEDIATELY when I hit the start button. I mean no cough sputter or rev instability whatsoever. Ever. It's like having an injected bike...


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presently running racked fcr's. saw a dyno chart somewhere for the individual setup and they made more power through the entire rpm range. very impressive!the problem for me is sourcing all the parts as no one sells the complete kit anymore.2 rear manifolds dual throttle cables and i believe different carbs.can anyone elaborate? ok bruce?
 
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