Still trying to get my head around these bike carbs... I've sort-of asked this question before, and had a few sort-of answers, but I'm still sort-of confused.

Will CBR600 carbs work if installed horizontally? Has anyone done it (and any pictures)? They are Keihin carbs, so are probably very similar to those found on other bikes.

I looked at the float chambers and thought that maybe it would be a good idea to angle them so that the join line to the main body is horizontal - this gives an angle of around 25 degrees above horizontal.

Then I looked at the pictures in a bike manual and realised that in their original location they were about 10 degrees off vertical!

Looking at the pictures of Jacko's and Tony Bond's work, they angle theirs up a bit (but different angles!).

I have a strong suspicion that it'll work in almost any angle, as long as the float chamber is approximately down a little bit, but I'd hate to put in a load of effort and find that it doesn't work!

All clues appreciated...
David


[Edited on 1/10/07 by David Jenkins]

As far as i have been led to believe the join in the float bowl should be vertical, the only other thing bogg bros say the R1 carbs should sit at 35 degrees from horizontal. I think if it is near enough that the join is horizontal it should be ok.

I just made my manifold so the float bowls were horizontal, I thought at the time that's how it had to be.

There's a picture of a Bogg manifold for a v8 with 2 sets of carbs, the carbs are no-where near horizontal, but must work (I'd imagine)



I'm not sure what carbs they are, but they look familiar

Presumably you could to an extent compensate for a new angle of float valve by twisting the tab but you could only do this to a certain extent as it would reduce the amount of float movement in one direction....

I am also using cbr600 carbs and am worrying about the mounting angle. I have read other posts and looked at many pictures in photo archives. On searching the net I have found that carb manufacturers offer both sidedraught and downdraught carbs fitted to different bikes. Unortunately the cbr 600 carbs [33mm Keihin] I have are classed as downdraught. So in theory they should be mounted with the chokes mounted vertically. Am I also worrying unnecessarily [img]http://locostbuilders.co.uk/upload/a625830-9008_1[1].jpg[/img]

quote:

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Originally posted by Bigheppy
I am also using cbr600 carbs and am worrying about the mounting angle. I have read other posts and looked at many pictures in photo archives. On searching the net I have found that carb manufacturers offer both sidedraught and downdraught carbs fitted to different bikes. Unortunately the cbr 600 carbs [33mm Keihin] I have are classed as downdraught. So in theory they should be mounted with the chokes mounted vertically. Am I also worrying unnecessarily

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I spoke to Bogg Bros the other day and was told the R6 carbs I am fitting will be fine at any angle. On the bike the intakes are almost vertical, I hope they are correct as mine will be horizontal, so they fit under the bonnet with no cut outs.

GSF Bandit carbs are almost sidedraught a set of a 600 would do better still a set from a 1200 bandit. I am using 1200 daytona carbs which are sidedraught.

Do these pics help? Not easy to get camera in at a good angle but you can see the float split line and also the angled line just above.
Rescued attachment 02102007263.jpg

i also spoke to Boggs about angles. I opted for a shallower angled manifold than normal to get the filter exitting in a good position. They were adamant that the angle wasnt too important as bikes rarely travel on level ground without corners (and also discussed the V8 installation which worked a treat).

Originally i thought the angled line was the marker, but float split line is probs more often used.
Rescued attachment 02102007264.jpg

Not sure about the "bikes never travel on level ground" bit, as the carbs go across the engine so would only tilt side to side. And that V8 installation almost has them at the correct angle (just off vertical!).

Be that as it may...

I had a play with them this afternoon - the float closes the valve at almost any angle, but who knows what fuel level would result?

The good news is that it looks like the carbs can be split apart - all that would be required are spacers (easy), extended fuel connectors (reasonably easy), extended throttle links (reasonably easy) and some mucking around with the SE gizmo operating mechanism (easy but fiddly).

Now if someone can convince me that the carbs would work horizontally, the manifold would be dead easy!



[Edited on 2/10/07 by David Jenkins]

Now im confused. I thought the V8 install had the floats at completely the wrong angle to a bike and that the aim was to have the float bowl split line somewhere near horizontal (or at least the line above to be horizontal).

Anyway mine work OK as in the pic which isnt far away to how Boggs would normally do the manifold (and others from what ive seen).

I used ZZR1100 carbs originally like Darren to make my manifold. I kept the float bowl split line fairly flat and have since switched to ZX9R carbs that look very similar.

The engine starts and runs very nicely....