Hi All

i have been put your way as the best place to discuss bike carbs so here goes.

I am currently planning on running cbr900 carbs on my 924 2ltr n/a.

i am getting a manifold base made by short track and then plan to weld the inlet tubes to the base and match to the carbs,

first off will mild steel be acceptable for this application?

what is the ideal length on the inlet tubes to gain good torque power ect?

with regards to the carbs am i best off using the fuel pump that the original bike uses? or best to use a facet pump and filter king regulator?

what are the ideal jet sizes need to run the size of engine. mains and others?

also can you buy bigger jets or are they a drill out job?

and also what sort of gains are people seeing with this over the old injection or old carb ect?

cheers

Ben

Inlet length isn't a one size fits all parameter. It depends on lots of factors including whether you want a broad power range or a peaky (max BHP) power curve.

Best use the fuel pump from the bike the carbs came from.

Jet sizzing is also something that requires a trial+error approach.

Welded mild steel is fine for a manifold....

quote:

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Originally posted by benlg924
Hi All

i have been put your way as the best place to discuss bike carbs so here goes.

I am currently planning on running cbr900 carbs on my 924 2ltr n/a.

i am getting a manifold base made by short track and then plan to weld the inlet tubes to the base and match to the carbs,

first off will mild steel be acceptable for this application?

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quote:

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what is the ideal length on the inlet tubes to gain good torque power ect?

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quote:

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with regards to the carbs am i best off using the fuel pump that the original bike uses? or best to use a facet pump and filter king regulator?

---

quote:

---

what are the ideal jet sizes need to run the size of engine. mains and others?

---

quote:

---

also can you buy bigger jets or are they a drill out job?

---

quote:

---

[and also what sort of gains are people seeing with this over the old injection or old carb ect?

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quote:

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[cheers

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thanks for your quick replies.

mild steel it is then, did you treat it with anything or just leave it natural?

i will get some tiny drill bits then and maybe a few spare jets just in case.

did you have to build a supporting hanger/bracket to take the weight of the carbs?

are you using a air box or filter/sock option? i plan to use the original fireblade air box

ireblade fuel pump it is then although they are hard to find at the moment for some reason.

dont suppose you have any pics of your set up?

cheers

Ben

Paint your steel manifold on the outside to prevent rust and it looks better.

quote:

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Originally posted by benlg924


i will get some tiny drill bits then and maybe a few spare jets just in case.

did you have to build a supporting hanger/bracket to take the weight of the carbs?

are you using a air box or filter/sock option? i plan to use the original fireblade air box

ireblade fuel pump it is then although they are hard to find at the moment for some reason.

dont suppose you have any pics of your set up?

cheers

Ben

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Have a look in my photo archives under zx9r carbs & manifold
Jacko

I've recorded my experiences on my website - see 'www' button at the bottom of this post, & follow link for bike carbs.

Not saying that it's the way you should do it - just the way I did it!

quote:

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Originally posted by David Jenkins
I've recorded my experiences on my website - see 'www' button at the bottom of this post, & follow link for bike carbs.

Not saying that it's the way you should do it - just the way I did it!

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i plan to keep the original spacing and make the manifold match with bends in tubes. so will probably use the standard air box for a while until i can either make another or go down the sausage filter route.

i am now about to attack ebay on the hunt for a 900cc fuel pump

cheers for all your help so far

great images and information

Ben

Any pump for one of the larger bikes with carbs will do the job...

hi

found this pump

http://cgi.ebay.co.uk/Honda-CBR900-RRN-F....parms=72%3A1301|66%3A2|65%3A12|39%3A1|240%3A1318

just wondered where I would wire the wire into and also what is the other pipe coming from the bottom, I take it the two top ones are the inlet and outlet?

sorry for stupid questions just trying to get my head around it all.

the manifold is being made as we speak so nearly there!

also anyone know of a garage or rolling road that can set my car up i am in the west midlands area.

cheers

ben

got my fuel pump eventually just out of interest what colours are what on the wiring on pic below

just to let you know i have started a build thread at

http://retrorides.proboards86.com/index.cgi?board=readersrides&action=display&thread=54569&page=1

if you want to follow it online

little thursday update

these arrived through the post today,




they guys at short track motorsport knocked me iup two after my first one was lost in the post cracking guys so if you need any manifolds or metal work give jason a call they are ace.

now all i need to get is the tubing now in around 40mm internal diametre and i am away.

still need to get the chock and accelerator cables and then a little silcon to connect them together.

looking forward to getting cracking now

hi,

this is a bit off at a tangent , but there seem to be lots of bike carb experts on this thread- I have a fuel starvation problem with my r1 carbs through left hand bends on the track- i am running a competition spec facet solid state fuel pump- but the carbs run fine without any regulator- no fuel leaking. could this mean there is some other blockage or problem causing the starvation? from one of the posts- this pump should have fuel leaking everywhere?

LEs

hi all

my tubing should be here tomorrow to get cracking on the manifold and i was wondering if peopl ehave made the extra tube for the vacume?

do i just run 1 vacume feed from #4 or all 4 or is it not really needed?


all help would be great so i can get started

cheers

Ben