fuel overflow probolems!

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stevie
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fuel overflow probolems!

Post by stevie »

Hi all, im getting my nc30 back together after a 4 year hibernation, the reason she hasent been used for so long was i didnt have the time space or money to sort her out, and iv been using my fazer as transport, the probolem is when i get the carbs & everything on & hook up the fuel tank it is filling up the cylinders with fuel, mainly number 4, front right. now iv checked all the obviouse stuff like float heights blocked jets ect. and they all seem to be in good working order, i thought it may be a probolem with the carbs so i got a new set, iv just put her back together and the same thing is happening, its driving me insane as i cant work out why! my bike is a 92 uk model nc30 running nc35 carbs with full hrc carb kit and air box, running 142/145 mj, the B needles on the longest setting, hrc emulsion tubes, slide springs and vell stacks, i have done the fuel tap mod so the carbs are gravity feed, but i cant explain why the fuel wont shut off as all the float switches are good and the carbs are clean, and the likely hood of another set of carbs having the same probolem as the first is slim!
Any help would be greatly appreciated as this is realy driving me nuts and i wnt my bke back as im fed up of riding the fazer, thanks.
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Re: fuel overflow probolems!

Post by hunter »

I don't know what you mean by float switches,
But to me this sounds like worn float needles,If the float levels are correct they should stop the fuel running through,
If the needles are worn then the fuel won't shut off,
The other thing that could contribute to this is your fuel tap,Does it have the HRC mod.
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Re: fuel overflow probolems!

Post by porndoguk »

hunter wrote:I don't know what you mean by float switches,
But to me this sounds like worn float needles,If the float levels are correct they should stop the fuel running through,
If the needles are worn then the fuel won't shut off,
The other thing that could contribute to this is your fuel tap,Does it have the HRC mod.
+1 Yeah just that,

fuel flows from the tank too two t pieces and straight to the float valves if the height is right then chances are its the float valve/needles

Nothing more to check on that problem realy
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krisztian_andre
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Re: fuel overflow probolems!

Post by krisztian_andre »

They sell float valve needles here for 6 GBP each which is a ripoff. We should find the manufacturer and order 500 pieces and rick-o could distribute them. Price should be around 250 GBP for 500 pieces or less.

http://www.chinesemotorcyclepartsonline ... NDL001.php
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speedy231278
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Re: fuel overflow probolems!

Post by speedy231278 »

If you think 6 is bad, have you seen the Honda price? £20 a shot at DSS and I reckon that's stock from a job lot they got somewhere, when I did my spreadsheet of prices about a year ago they were £33!!!
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Re: fuel overflow probolems!

Post by Neosophist »

I dont understand people complaning about the price of precision made parts for old bike that are in low supply / demand like there is some cheaper alternative somewhere.

float needles are precision made parts. They genuine ones are proably made by kehin who make the carbs.

Where do you get your approx figures from? and is it for proper ones or fake ones?

They should ideally be replaced as a set as they wear together.

It may be a small part but it is important, it is all that is stopping the petrol leaking everywhere, if it fails while your out and about you are stuck.

To the op. Did you get the carbs apart?

most likely is that the floats are stuck, make sure the float bowls are clean and that the floats move ok.

After re-assembly if they are stuck open bang the carb float bowls with the handle of a scrwedriver, not trying to break the bowls off but the tapping shoudl dislodge the stuck float and seal the fuel.
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stevie
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Re: fuel overflow probolems!

Post by stevie »

Thanks for all your replies, by float switches I did mean float needle, iv taken them all out and soaked them in wd40, they are working as should, I allso found that one of the screws securing the float bowel had a striped thread so wasent tightening up fully, it's all back together now & seems to be working as it should, again thanks for your help, it is appreciated.
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Re: fuel overflow probolems!

Post by Maelstrom »

:plus: to Neosophist

I am often asked why I do not include float needles in my carb seal kits, like some other kits that are available, and the reasons have just been enunciated perfectly by Neosophist. Being viton tipped, it is a part that rarely needs replacing and if it does, my advice is to buy genuine.
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krisztian_andre
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Re: fuel overflow probolems!

Post by krisztian_andre »

From needle valve manufacturers. I don't understand fake and proper in this context. They are mass produced parts and not specific to this bike only.
You can get valve seats too for 1 or 2 quid total.
The only problematic part I see here is the correct spring rate of the needle.
Neosophist wrote:I dont understand people complaning about the price of precision made parts for old bike that are in low supply / demand like there is some cheaper alternative somewhere.

float needles are precision made parts. They genuine ones are proably made by kehin who make the carbs.

Where do you get your approx figures from? and is it for proper ones or fake ones?

They should ideally be replaced as a set as they wear together.

It may be a small part but it is important, it is all that is stopping the petrol leaking everywhere, if it fails while your out and about you are stuck.

To the op. Did you get the carbs apart?

most likely is that the floats are stuck, make sure the float bowls are clean and that the floats move ok.

After re-assembly if they are stuck open bang the carb float bowls with the handle of a scrwedriver, not trying to break the bowls off but the tapping shoudl dislodge the stuck float and seal the fuel.
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Re: fuel overflow probolems!

Post by Neosophist »

The Honda part is 16011-MR8-003 for the set of valve seat, valve needle and associated gubbins.

Dave silver only sells a repro part for 11 quid per carb.

And by fake and original I thought it would be obvious.

Original would be a part made by the manufacturer or an approved 3rd party that is built to original standards.

A fake would be your typical low quality chinese knock-off that might fail at any time.

While the float needle and valve seat are probably used on several different carbs I wouldnt say they are mass produced without checking the exact data.

Most bikes these days are fuel injected for a start
xivlia wrote:i dont go fast on this bike so really do not need a rear brake.. /
vic-vtrvfr wrote:Ask xivlia for help, he's tackled just about every problem u could think of...

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