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Setting Float level


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80XAR

 
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Setting Float level

Mon Apr 05, 2010 2:20 am » Post: #1 » Download Post

I have searched this forum, and cannot find one word reguarding how to set the float level.

Yes, it should be 13mm.
So where is that measured from exactly ?
Im assuming it is from the empty position, to the point at which it starts to let fuel in (as in to say it has 13mm of fuel in the bowls)
Am i to measure the sweep of the bowls, or is there something else i should be measuring off ?

I know it sounds like a really basic question.
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nsrdownunder

 
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Mon Apr 05, 2010 3:52 am » Post: #2 » Download Post

Hi Mate
I have seen this somewhere on here before but not shore where maybe andy or fonty will know but to do float height hold carbs at 90 degress and measure from base of carb (where the float cover screws on) to the bottom of the float.
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Mon Apr 05, 2010 4:02 am » Post: #3 » Download Post

You'll need a ruler that's cut off so zero is on the edge of the stick. What I mean by that is you set the ruler on it's end, so you want to start right at zero there.

Holding the carb on it's side, place the ruler where the bowl would normally attach and keep on eye on the needle. Rotate the float so the needle closes off the fuel, and take note of the "highest" part of the float compared to where you're measuring from. You do not want the spring loaded plunger to move into the needle, so recheck this measurement a couple times. Use a small screwdriver to adjust the measurement and don't go nuts - it's easy to check, adjust, check, adjust, etc so you don't have to justify bending the heck out of the tab and getting it way out of whack.

Be sure to check both sides of the float as that can get you messed up if they are wildly different.

Craig
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Andy
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Mon Apr 05, 2010 5:35 am » Post: #4 » Download Post

Nearly 60 seconds to find this thread! Wink

http://nsr250.net/forums/viewtopic.php?t=5322&highlight=float

Maybe you searched for "flaot"?! Laughing
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80XAR

 
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Mon Apr 05, 2010 11:23 pm » Post: #5 » Download Post

Andy your speed reading skills are phenominal.

That thread is not in the top 50 search returns for 'float'
After reading through the top 25 or so, i gave up.

Its a very good thread though describing how to do it.
Is there any chance that info could be transfered into the workshop manual ?
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jimmy13
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Wed Apr 07, 2010 12:04 pm » Post: #6 » Download Post

I always use a vernier caliper set correct height then use gauge marked "3" in the following image

http://upload.wikimedia.org/wikipedia/commons/9/96/Vernier_caliper_new.png

Jim
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Wed Apr 07, 2010 1:37 pm » Post: #7 » Download Post

Tyga, if I recall, sell a genuine Honda float tool. Well worth the money.
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80XAR

 
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Tue Apr 13, 2010 1:46 am » Post: #8 » Download Post

Thanks for all the info guys

So, you measure from the lowest part of the float (the side of the float that actually floats on the fuel) to the surface of the carbie that the bowl mounts too ?
At this measurement (13mm), the little tappered plug needs to be blocking the flow of fuel.
Is this correct ?
If so, how hard should the the tapered plug be resting against the the gallery ? Just resting or fairly firm ?
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bandit_7
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Tue Apr 13, 2010 7:34 am » Post: #9 » Download Post

Hey 80XAR,

I'm lead to believe that when the float bowl gasket surface (bottom of carbs) is sitting vertical, this is when you would take your measurement. If I am wrong I hope someone tells you different. If I am right I have finally made a slightly correct assumption. As far as pressure on the seat I took no notice.

Andy

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Andy
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Tue Apr 13, 2010 10:08 am » Post: #10 » Download Post

Well the whole idea of the float is to open and close the valve as necessary, so setting it is done at the point where the needle just makes contact with the seat... this means as the fuel level rises to the set height, the needle shuts the flow off and the carb doesn't overflow!

So, yes the carb body should be pretty much horizontal (gasket face vertical/float pivot pin at the top/float hanging down), and then just tip the carb so the needle sits on the seat. You will notice there's a tiny sprung pin on the bottom of the needle; that shouldn't be compressed.
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80XAR

 
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Tue Apr 13, 2010 10:11 pm » Post: #11 » Download Post

Awesome
Thanks Andy.
We pulled them down for a clean, and were unsure, so we reassembled them without modifing the float, and now one is overflowing.

I noticed that there is fuel mist coming back out the of carb that is overflowing.

The engine starts and runs ok. Its a little flat off idle, but i need to adj the air screw, and put the air box back on. The pulsing i can feel with my hand at the carbie mouth is the same on both carbs, just one has fuel mist once you shut the throtle.
Is this related to the float being set incorrectly ?
I was just blipping the throttle from idle to about 4k. It did not seem to have the mist on acceleration, only on decel.
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Neal

 
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Wed Apr 14, 2010 7:26 pm » Post: #12 » Download Post

That mist is blow back from the reeds
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Andy
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Thu Apr 15, 2010 2:02 pm » Post: #13 » Download Post

"Stand off" is common... it's how we stop everything behind the carbs rusting or corroding! Laughing
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Dave Ett
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Thu Apr 15, 2010 5:26 pm » Post: #14 » Download Post

You've probably got it sorted already, but here's a few pics I took while I had my carbs apart:

Removing the float pivot pin:



Extracting the pivot pin completely:



The float valve showing the wee springy thing on the end under the wire loop - check for damage on the black pointy bit:



The valve seat - check for damage or grot stuck to it:



Setting / checking the float valve height:


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80XAR

 
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Thu Apr 15, 2010 10:39 pm » Post: #15 » Download Post

Thanks for the pics Dave.
Did you allow for the 5thou of rust on those verniers ?
I am pulling them back off again this weekend, so they will come in handy.

Is there any reason why one cylinder would be misting and not the other ?

Ill reset the floats and see if it continues.
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