I had a Lectron 44hp from mr HP didn't like the carb suck sold it on ebay what other carbs are out their that would work nice on my DFS you can see the spec of what I have on the mods, thanks for the input as well let me know were the carb can be located and what I can expect to pay for it.

 

Well you have the other Lectron carbs, diff size ones, you could get dual 39mm ones, or the Mikuni 45mm carb

 

I got a EFI and im lovin it alot. Get one of thoes $1500

 

The other day I was flowing the intake between the head and carb. With the head off I checked the port sizes of the intake side of the intake and the port sizes going to the head.

If you work out the surface area of the stock carb and the intakes intake it comes to just under 42mm. This give you a surface area of 2.14". The intake has two outlets, both reading around 34mm each. Two 34mm intakes have a combined surface area of 2.82"
Now the intake needs to be flowed correctly to allow the 44mm of the new carb to make any difference. If the inside of the single intake is still around 42mm you are not flowing more air than what the 42mm carb will flow. The restriction is on the intake side not the carb.

You need to measure and grind the whole intake to match it to the larger carb. Maybe you have done it, maybe not.

Now, having bigger intakes to the head than what the carb can flow is not a good setup. You are loosing intake velocity. The two 34mm intakes to the head actually need a minimum of a 48mm carb. The surface area of a 48mm carb is 2.81" Now the stock intake will never allow a 48mm carb. I don't think it has enough metal to handle that sort of grinding and modification.

In all my studies, it is better to decrease intake port size as it gets closer to the valve opening. This means you actually need a bigger carb than a 48mm to create a high velocity intake port. Having a smaller carb as what the intake can flow will loose you intake velocity and in the end HP.

The older BMW F650's 97-99 models had a duel carb setup that matched the intake port sizes to the head much closer. It came with 2 x 36mm carbs. The two 36mm carbs had a combines surface area of 3.17" This is the same surface area as a 51mm carb. It is the same engine as the one in the DS and it made stacks more power with those carbs.

If I was you, I would see I could get an old F650's carbs and intake and maybe the airbox. It should bolt right on and you should only have to worry about getting air cleaners on them. Maybe even modify a F650 intake to work in the DS frame.

You will outflow any other single carb on the market and wake up that DS motor the way BMW did years ago.

People always try to invent new things. They never look back and see if someone has not figured this thing out a long time ago. BMW did, so use what parts they have. It might even be much cheaper than getting a brand new single carb.

 

Thx for all the suggestions, freez your an animal...I can see your a hardcore DS guy...good thing, I will look into this and appreicate all suggestions from everyone.

 

How long have you had your EFI? Is it the self adjusting third generatrion setup with wideband O2? When I e-mailed them a few weeks ago on pricing they quoted my $2000 for the EFI. I have yet to hear of anyone actually paying that much for the setup.

 

Freez the stock intake will open to 48mm without any problems. Been doing it for about two years now.

 

I got my for $1500 at KMS and I am getting NOS. I like the EFI its great and it is self adjusting.

 

Hey Freez, someone on the board already runs the twin Mikunis, can't remember who.. PAMI has a kit for them on their website. 36mm Mikunis

 

Thanks MisterHP. I did not know it was possibleto open the stock intake to 48mm. Do you use a new rubber boot with it, or does the stock boot also work?