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Bike Carbs
davie h - 29/9/08 at 11:13 AM

I bought a set of bike carbs of e bay (drunken purchase) they are a set of yamaha yzf 750 they have the tps and look very clean. what i need to know is will they be ok for a 1.8 zetec. Also when looking into them they have a black plastic slider how does this move when the engine is running. there are two short plastic tubes and if i blow air into them the plastic sliders move as you can see i know nowt about carbs never mind bike carbs

thanks Davie


zilspeed - 29/9/08 at 11:31 AM

Could you do a quick pic ?

Initial reaction is that they should be fine.

Your 1.8 revs to 6,500 ish, the 750cc engine they came off made 125bhp ish at nearly 12,000 revs.


UncleFista - 29/9/08 at 11:31 AM

quote:
Originally posted by davie h
I bought a set of bike carbs of e bay (drunken purchase) they are a set of yamaha yzf 750 they have the tps and look very clean. what i need to know is will they be ok for a 1.8 zetec. Also when looking into them they have a black plastic slider how does this move when the engine is running. there are two short plastic tubes and if i blow air into them the plastic sliders move as you can see i know nowt about carbs never mind bike carbs

thanks Davie


We've used CBR600 carbs on the same engine, I just worked out what BHP I was expecting and bought carbs to match. Seemed to work

The slides open up with air pressure as the engine runs, you can see them pulsing when idling. It's normal


davie h - 29/9/08 at 11:36 AM

zil

pictures coming up will go into the garage and take them

thanks for the replies just didnt want to think i had paid good money for a donkey if you know what i mean

Davie


will121 - 29/9/08 at 12:03 PM

if they are about 38mm diameter, should be ok, for info on carb operation and jetting see http://www.motorcyclecarbs.com/carbs101.pdf


davie h - 29/9/08 at 12:07 PM

Zil here are some pictures of the carbs


bike carbs 3
bike carbs 3


you can see the two black plastic tubes i was talking about and the sliders



bike carbs 1
bike carbs 1




bike carbs 2
bike carbs 2


whitestu - 29/9/08 at 12:08 PM

I'm using ZX6R carbs [apptox 37.5mm] on a 1.8 Zetec [and will be putting them on a 2.0 soon. They work great on the 1.8.

Stu


zilspeed - 29/9/08 at 12:11 PM

Those look like they can be spaced if you want to which is great.
Bore sizes also look sensible too. Should make for torque in the mid range.

Hope they work out well.


BenB - 29/9/08 at 01:40 PM

They're constant velocity carbs similar to those used on most motorbikes.

In answer to "how to they work" the answer is "very nicely thank you "....

The short answer is the piston moves up / down accourding to the vacuum. The piston has the needle attached which dips it in and out of the primary jet...