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Mikuni 33 smoothbores

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FOZ1A
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Mikuni 33 smoothbores

#1 PostAuthor: FOZ1A » Mon Dec 17, 2018 2:16 pm

Just got a set of these and would like some advice on base settings. The motor is 1075, flowed head with oversized valves, possibly a set of cams to follow. Just upgrading from 29 smoothies.

Cheers

foz
Rickman CR1000, Ducati Diavel, Gilera Nordwest.

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KWACKERZ1
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Re: Mikuni 33 smoothbores

#2 PostAuthor: KWACKERZ1 » Tue Dec 18, 2018 4:10 pm

This may help,
From and old tuning article
Mikuni 33mm Smoothbores
For those of you who still own these carburetors a little jetting trick. In order to get better throttle response install 0.6 air correction jets. This allows you to run a smaller main jet while still giving you approximately the same air fuel ratio as before. Good starting point is 4 main jet sizes smaller than you previously had. Also installing a O-6 needle jet will help lean out the mid range.

My 33's on an 1170 or a 1075 runs fine on
120 main, airjet 0.06 jet needle 161.0.6 (6dj30) pilot jet 17.5 throttle valve cutaway 1.5 (note suzuki ones have a different cutaway) air screw 3/4 out. (this is running open bell mouths) float height 23mm

If you have 1.2 air jets run 127 mains.
Hopefully this helps
P.S. Did you sell the 29's ?

paulmceleney
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Re: Mikuni 33 smoothbores

#3 PostAuthor: paulmceleney » Tue Dec 18, 2018 7:30 pm

I had 130 main jets in my 1075 33 smoothbores

Julian_Boolean
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Re: Mikuni 33 smoothbores

#4 PostAuthor: Julian_Boolean » Wed Dec 19, 2018 1:31 pm

How do you tell Suzuki ones from Kawasaki ones?
I've got a set in the back of the garage and I've no idea what they came off.
An expanding collection of parts pretending to be a Z1100R and a Yamaha FZ750

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KWACKERZ1
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Re: Mikuni 33 smoothbores

#5 PostAuthor: KWACKERZ1 » Wed Dec 19, 2018 2:52 pm

The slides come in various sizes and the size is determined by how much is cutaway from the backside of it. The larger the cutaway, the leaner the mixture (since more air is allowed through it) and the smaller the cutaway, the richer the mixture will be. Throttle valves have numbers on them that explains how much the cutaway is. If there is a 3 stamped into the slide, it has a 3.0mm cutaway, while a 1 will have a 1.0mm cutaway (which will be richer than a 3).

Julian_Boolean
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Re: Mikuni 33 smoothbores

#6 PostAuthor: Julian_Boolean » Wed Dec 19, 2018 4:21 pm

thanks
An expanding collection of parts pretending to be a Z1100R and a Yamaha FZ750


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