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29mm SMOOTHBORES

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Garn 1
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29mm SMOOTHBORES

#1 PostAuthor: Garn 1 » Mon Feb 09, 2015 10:02 am

Anyone tell me what the setting is for the brass floats from the body rim lip when up-side-down. I think for these 29 Smoothbores it's about 24mm?
Can't seem to find the dimension anywhere! Can't find my threaded adapter with plastic tube either!

I'm using 115 main jets & 17.5 pilots. will go on a 900 to 1000cc engine.
Also, any comments on these jets would be appreciated.

RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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z1000puddin
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#2 PostAuthor: z1000puddin » Mon Feb 09, 2015 10:30 am

Garn
23.5 - 24.5mm so middle would be 24mm

I am running 120 mains & 17.5 pilots
Muy green bike is 1075cc with ps2x cams, open ally trumpets & an under seat exhaust
Zed til Dead

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#3 PostAuthor: PAULJAC47 » Mon Feb 09, 2015 4:58 pm

Garn plastic adapters, i use in line air line couplers from my local aquatics...Paul J
PAULJAC47,,,,,"She may not look like much, but she's got it where it counts, kid."
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#4 PostAuthor: Gus » Mon Feb 09, 2015 5:26 pm

PAULJAC47 wrote:Garn plastic adapters, i use in line air line couplers from my local aquatics...Paul J


Have you got a link as I can't seem to find any?

Found these

http://www.ebay.co.uk/itm/301508548370? ... 1436.l2649

Cheers

Gus
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Garn 1
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#5 PostAuthor: Garn 1 » Mon Feb 09, 2015 10:48 pm

Thanks Puddin, that will get me out of trouble.
Looks as so I might venture to 120 mains.

Long term I will have to buy or make one of those adapters to suit the 17mm bottom nut. Thanks Pauljac.
Are they the same thread as the early 28 mm Mikuni's?
What is the Pitch of these metric plugs?
* Note for others.....I did get caught thinking the needle & seat assembly would be the same thread, only to find the 29 mm had a slightly larger thread and fibre washer.

Another for you experts... I have two sets of 29 Smooth-bores.
One has markings PI/ 51
The other has markings PO/ Y1
They both look the same any comments?
RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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#6 PostAuthor: Garn 1 » Tue Feb 10, 2015 9:14 am

Guys, a friend saw me today and had an early 28 Mikuni carb 17 mm drain plug with him. The 29mm Smooth-bores have a smaller diameter thread than the early 28mm drain plugs.
I still have to work out the pitch of these 29 drain plugs.

To save a new post, I thought I would just edit this one above to show my finding for future reference.
Size of 17 mm drain plugs for 29 Soothbores..
Bolt head... 17 mm across flats.
Thread size 16mm x 1mm pitch.
Image
Found an old 17 mm plug, drilled the end out and soldered in an old petcock spout.
Intend to initially set float levels at 24mm (re puddins post) and then check wet with above gauge.
RegardZ
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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#7 PostAuthor: Garn 1 » Thu Mar 12, 2015 6:26 am

Just to clear up some info on Smoothbores fuel level.
I adjusted the levels using the upside measurement method, using Puddin's 24mm. I found this to be incorrect when checking with the plastic tube method.
It was far too high, meaning the measurement was not 24 from the gasket face, but rather 24mm from the 2.5 mm flange.
it was an easy mistake to make.
Image Image
This is where the fuel comes to with measurement from gasket face ... too high!
The measurements should be taken from top of flange not gasket face if using 24-25 mm
I did ask Wg, he agreed it was far too high and suggested 3 to 4 mm down from the visible flange join.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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Re: 29mm SMOOTHBORES

#8 PostAuthor: johny brando » Wed Mar 18, 2015 12:04 am

Garn 1 wrote:Anyone tell me what the setting is for the brass floats from the body rim lip when up-side-down. I think for these 29 Smoothbores it's about 24mm?
Can't seem to find the dimension anywhere! Can't find my threaded adapter with plastic tube either!

I'm using 115 main jets & 17.5 pilots. will go on a 900 to 1000cc engine.
Also, any comments on these jets would be appreciated.

RegardZ.


Late entry on my part. i run 29mm Smooth bores too & 24mm from Float bowl body face(with NO gasket ) just use normal a Vernier Gauge or a Steel rule to set the height.

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Garn 1
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#9 PostAuthor: Garn 1 » Thu Mar 19, 2015 3:21 am

Thanks for reply JonnyB...... were they Brass floats used in that model 29's that you observed?
You saw a picture of my results? Does look awfully high level.
RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

johny brando
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#10 PostAuthor: johny brando » Thu Mar 19, 2015 8:26 pm

Garn 1 wrote:Thanks for reply JonnyB...... were they Brass floats used in that model 29's that you observed?
You saw a picture of my results? Does look awfully high level.
RegardZ.


Must be honest & say I don't recall...but I think they are Brass floats . I bought the carbs brand new in 1981 .Either way it does'nt matter the FLOAT HEIGHT is the same =Highest top edge face of the float .....24mm to the underside of the gasket i.e. against the Bodies gasket face !!!!It appeas that theres some confussion on this front!!!!!! Also Float Height & Fuel height are completely different & measured in a totally different ways ....both methods obtain the same goal but in a different way ....but you must take the measurements in a completely different manner. Like I said, just use a Steel rule or Vernier gauge & it will be correct then. If your concerned that you may have a float body leak or a float bouyancy issue which will of course then have a bearing on fuel cut off . Then to check this out first carefully submerge the brass floats in HOT water ( place a small weight on top of them to fully submerge them ) preferably in a clear glass vessel if possible so you see clearly whats happening ....leave it submerged for 2 minutes ,minutes & watch to see if any expanding gas within the float bubbles out anywhere...if None well it's fine ! is it leaks any gas at all = careful tiny soldering job. If you have the other CLOSED cell type Floats again submerge in Hot water & see if the either float Lists to one side if so some cells within have burst & are getting water logged= throw it away &buy new ones ! Cheers Johny B

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Garn 1
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#11 PostAuthor: Garn 1 » Sat Apr 11, 2015 9:03 pm

Some feedback re- smoothbore float settings
Wow! Those 29mm smoothbores really make a difference from the usual 28mm. I may still be running a little rich with my set-up, however, the throttle response is the best I've seen in my life with Zeds..... Standard bore Z1.
Thanks again for the advice. I can't say 24 mm was the answer but rather the setting with "hose" about 2mm, or so, below the flange marks (ref above pic ~ Post 1) I do think my original recommendation of this 24mm was based on floats made of plastic rather than brass.
Conclusion ~ "Hose" method better than "upside-down measurement" method for Smoothbores.
RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4


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