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Bike carbs for crossflow
Norfolkluegojnr - 30/7/14 at 07:11 PM

Well, It appears as suspected my dellorto dhlas are in need of rebuilding, something well beyond my skill set.

After using fireblade carbs on snrs Luego, I'd like to go down this road. U2U already sent to dan, but what carbs would you all recommend?

Any experiences good or bad, feel free to share!

tul214 - 30/7/14 at 07:56 PM

These

[Edited on 30/7/14 by tul214]

Norfolkluegojnr - 30/7/14 at 07:58 PM

Link not working?

tul214 - 30/7/14 at 08:00 PM

Should do now, click on the bike carb link.

Norfolkluegojnr - 30/7/14 at 08:17 PM

Fantastic, thanks

whitestu - 31/7/14 at 07:53 AM

If you select the carbs carefully you can get away without the most expensive / difficult part of the job which is buying / making an inlet manifold.

If you re-space the carbs as tul214 has suggested you can just mount the original bike carbs rubbers to a flat piece of 5mm aluminium and mount this to the head.

This works a lot better than using bits of silicon hose to mount the carbs to a fabricated manifold.

Carb choice comes into it as some are designed to mount at at angle and some mount horizontally. With the ones mounted at an angle [like the ZX6 carbs I have] you need to alter the float height quite a lot to get it running right at tick over. With horizontal carbs this can be avoided.

For a crossflow I'd be looking at a set of Fazer FZS 600 carbs and rubbers. There are some on ebay now for £35. I think these are a bit smaller than ZX6 / CBR600 carbs but should be fine on a crossflow.

Stu

[Edited on 31/7/14 by whitestu]

Norfolkluegojnr - 31/7/14 at 07:57 AM

Thanks stu.

You've lost me a bit on the manifold though - do you mean respace and make a simple manifold similar to the link above?

Alfa145 - 31/7/14 at 08:57 AM

I had R1 carbs on my Crossflow. Worked beautifully once RR setup, smooth through the full range. Had a bogg brothers manifold, but cheaper are available.

whitestu - 31/7/14 at 09:16 AM

quote:

Thanks stu.

You've lost me a bit on the manifold though - do you mean respace and make a simple manifold similar to the link above?



Sorry - I meant like this:

[img] manifold
manifold [/img]



All you need to make is a plate to mount the original bike carb rubbers to, which is really easy to make and mounts the carbs better than any silicon hose ever will.

Stu

Norfolkluegojnr - 31/7/14 at 09:19 AM

quote:
Originally posted by whitestu
quote:

Thanks stu.

You've lost me a bit on the manifold though - do you mean respace and make a simple manifold similar to the link above?



Sorry - I meant like this:

[img] manifold
manifold [/img]



All you need to make is a plate to mount the original bike carb rubbers to, which is really easy to make and mounts the carbs better than any silicon hose ever will.

Stu


Ah, I see, the rubbers bolt on. That makes a lot more sense now.

Are these carbs a horizontal fit then?

whitestu - 31/7/14 at 10:03 AM

quote:

Ah, I see, the rubbers bolt on. That makes a lot more sense now.

Are these carbs a horizontal fit then?


Fazer carbs are pretty much horizontal fit. I think they are 32mm bore. Mine are ZX6R (37mm bore] and should be mounted at an angle.

Mine are horizontal and work perfectly but I had to change the float height quite a bit in each carb as the fuel level at standard float height was too high when mounted horizontally, allowing flue to bled though making the mixture far too rich at tick over and low engine speeds.

This is easy to do though so I wouldn't let it put you off a set of ZX6 carbs or other similar ones if they come up.

Bike carbs are really good and when set up reasonably well they work brilliantly. Mine starts and ticks over hot or cold and runs with no flat spots pulling from pretty much tick over in 5th and revving cleanly with great MPG.
Set up was pretty easy with a wideband AFR meter as well.

Stu

Norfolkluegojnr - 31/7/14 at 10:57 AM

great thanks.

i'm not great with manuacturing so will probably opt for a Fastdan manifold. Useful info on the carbs though, and I'll look at getting a Wideband too.

coozer - 31/7/14 at 01:47 PM

I found it easier because you dont need to get the tube size to match the carbs, just the port size..





redturner - 31/7/14 at 01:53 PM

I have a friend who fitted his bike carbs at the wrong angle because it was going to foul some body work, biggest mistake he ever made and never got them running properly. I have R1 carbs on my Zetec onto a DanSt manifold (cheap at half price) with the float chambers dead flat as intended and have never had a moments trouble or a leak of any sort.....Weber dgv jets fit straight in so no poncing about drilling them out...

Norfolkluegojnr - 31/7/14 at 01:54 PM

Thanks Coozer - interesting design.

Is it mounted to a twin side draught style manifold? if so that could work for me and save the need for a separate manifold to be purchased.....

coozer - 31/7/14 at 05:20 PM

No mate, its my manifold that I made from 5mm plate and tubes.