f7r on throttle bodies

[cindral]

Hey guys,

Just a few questions about putting my 340 onto bike carbs.

I have recently installed the f7r into my 340 and am considering fitting some bike carbs on there. i have been offered a set with manifold.

Can someone tell me how they have set them up as they are gravity fed. My mate who had them on his clio said he was running two facet pumps one to send and one to return, and even then he said it was very temperamental and either worked very well or not at all!

I will be using my ally fuel tank, facet pump, and a fuel pressure regulator before the carbs themselves does this setup sound right?

All help would be much appreciated.

Cheers

Ross

[kaos]

think you might be wanting a swirl pot as well in there somewhere really

[filthyjohn]

It should be ok without a swirl pot, a low pressure pump will keep the carbs constantly fed without worrying about fuel starvation. I use a facet 1-4psi electric pump and Filter King fuel pressure regulator supplying 1.5psi. The bike carbs will be good at a simlar pressure. Don't worry about them being gravity fed, bikes go to all sorts of angles when wheelying, so they're always fed fuel under pressure to avoid feed problems.
You shouldn't need a return line to the tank, unless your carbs are from a bike that has one (can't imagine why a carb engine would need a return). One thing to watch out for is that the carbs like to be mounted at the same angle as they would be on the bike. If it's a bit off, it'll mess up the floats. This may explain your buddy's tempramental running.
Hope this helps.

[cindral]

Cheers guys for the info. John i think you might be right there! can anyone point me in the right direction for a manifold? i would make one myself but iam having trouble accessing the tools required.

[cindral]

It should be ok without a swirl pot, a low pressure pump will keep the carbs constantly fed without worrying about fuel starvation. I use a facet 1-4psi electric pump and Filter King fuel pressure regulator supplying 1.5psi. The bike carbs will be good at a simlar pressure. Don't worry about them being gravity fed, bikes go to all sorts of angles when wheelying, so they're always fed fuel under pressure to avoid feed problems.
You shouldn't need a return line to the tank, unless your carbs are from a bike that has one (can't imagine why a carb engine would need a return). One thing to watch out for is that the carbs like to be mounted at the same angle as they would be on the bike. If it's a bit off, it'll mess up the floats. This may explain your buddy's tempramental running.
Hope this helps.

John did you drill out the jets at all?

Cheers Ross

[filthyjohn]

No but mine are Dell'orto car carbs, so I can just buy whatever jets I need. I heard that R1 carbs will accept weber jets, but can't say for certain. What exact carbs were you looking at? Bogg brothers near York make manifolds all day, charge about £175 or a one-off.
As a rule of thumb, get a set from a bike with half the engine size. They rev twice as high so the jetting is in the right ballpark.

[cindral]

by filthyjohn » 29 Apr 2009 12:50 am

No but mine are Dell'orto car carbs, so I can just buy whatever jets I need. I heard that R1 carbs will accept weber jets, but can't say for certain. What exact carbs were you looking at? Bogg brothers near York make manifolds all day, charge about £175 or a one-off.
As a rule of thumb, get a set from a bike with half the engine size. They rev twice as high so the jetting is in the right ballpark.
No but mine are Dell'orto car carbs, so I can just buy whatever jets I need. I heard that R1 carbs will accept weber jets, but can't say for certain. What exact carbs were you looking at? Bogg brothers near York make manifolds all day, charge about £175 or a one-off.
As a rule of thumb, get a set from a bike with half the engine size. They rev twice as high so the jetting is in the right ballpark.

I will be using R1 carbs. I was going to make my own manifold but for a piece of mind i may contact the bogg bros.

[filthyjohn]

R1 carbs should be roughly correct, and once set up should net 170-180hp on an F7R I'd have thought.

[cindral]

lol, 170-180bhp omg thats gonna shift! been on phone to bogg bros today got a quote off them! roll on payday! lol

[filthyjohn]

It certainly will shift. That's some really serious power:weight ratio, but you'll have to be careful with the prop and diff.

[xtrmjks]

No but mine are Dell'orto car carbs, so I can just buy whatever jets I need. I heard that R1 carbs will accept weber jets, but can't say for certain. What exact carbs were you looking at? Bogg brothers near York make manifolds all day, charge about £175 or a one-off.
As a rule of thumb, get a set from a bike with half the engine size. They rev twice as high so the jetting is in the right ballpark.

Dellorto don't make carbs anymore, still makes parts. I can get hold of any jets for Dellorto's, next day!
You can use weber jets on most bike carbs. No need for return line, as carbs are high flow, not pressure.

[Fuse]

You shouldn't need a return line to the tank, unless your carbs are from a bike that has one (can't imagine why a carb engine would need a return).
Hope this helps.

One situation I can think is carbs+turbo and enough boost and you would need a return line. That's because you'll need to raise the fuel pressure the same amount there is boost present and if you got 1 bar or more boost, not many carb pumps can give that much of pressure and enough flow, so it's usually EFI pump+fuel pressure controller in those setups.