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Change the Float Bowl Needle Valve (and lose your fuel pump)
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TOPIC: Change the Float Bowl Needle Valve (and lose your fuel pump)
#27365
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Re:Change the Float Bowl Needle Valve (and lose your fuel pump) 10 Years, 9 Months ago  
I am at the point that I want to ignore myself as well.

That answers something for me then. When the bike frame is leveled off the back mating surface is much higher than the front. I will try that next and repost.

Thanks for the info....

Huygens
 
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#27383
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Re:Change the Float Bowl Needle Valve (and lose your fuel pump) 10 Years, 9 Months ago  
Don't know if this will help, but it may be worth checking. Found this while following a link from an unrelated post; http://weislake.com/sig/mucker/carbslide.htm

Good luck!!

In The Wind,
Aaron


Sorry if this doesn't come across as a direct link. Still trying to figure that out!!

BTW; I did this same mod a few weeks ago and the only problem I've run into is having to switch to reserve before the fuel light comes on. Bike coughs and sputters, I switch to reserve and a few miles later the fuel light comes on. I haven't vented the gas cap though, so I'm wondering if that would correct the problem.

Post edited by: 2005Roadstar, at: 2007/05/21 10:28<br><br>Post edited by: 2005Roadstar, at: 2007/05/21 10:55
 
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#27447
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Re:Change the Float Bowl Needle Valve (and lose your fuel pump) 10 Years, 9 Months ago  
Huygens, I am the one who posted the &quot;flow rates&quot; for fuel flow with &amp; without vented gas cap. I am using the stock petcock &amp; the same size rubber tubing as stock (just better quality !). My bike has a K&amp;N filter in a yamaha billet airbox, no AIS, no fuel pump and, until recently, modified stock exhaust. It'll wrap the speedometer even with the windshield on. I suspect that one of two things is happening to you. Either

a) as Doc suspects something in your main jet &quot;circuit&quot; is not right. This is the circuit of the carb that comes into play from about 3/4 throttle to full throttle. It is not so much a matter of RPM as throttle position. If you keep the bike under 3/4 throttle will it eventually hit higher speeds ? Does it display the same problem in lower gears, or just 5th ? Can you run it right up to near redline &amp; hold it there in a lower gear without fuel starvation ? How do you have the fuel line run ? Is it directly from the petcock to the carb &amp; is it reasonably level ? If you remove the drain screw from the carb does the fuel run out ? If you remove the bowl does the fuel run when you drop the floats &amp; stop when you lift them ? Are the screws on top of the carb tight, &amp; is the rubber diaphragm seated properly ? Is your main jet completely drilled through (don't laugh, it's happened). Is the needle jet installed properly ?

b) Something else is messed up that is fooling you into chasing a carb problem that may not exist. How old are the plugs ? Do you have good spark ? Do you have any air leaks or open hoses ? How is the oil level ? Too much oil can cause weird problems at higher rpm's. If you changed the air box, are you sure you removed/capped/replaced all the hoses, etc. Check everything over to ease your mind and confirm that it's a carb problem.

I once chased a similar problem for a month in my GSX-R1100, only to eventually determine that the spark plugs were to blame. I almost drove myself crazy !! If you think it a pain taking off one carb, try pulling FOUR CARBS out 20 or 30 times !! It's enough to make you insame . . . . . sorry . . . it still hurts . . . .

Rup
 
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#27986
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Re:Change the Float Bowl Needle Valve (and lose your fuel pump) 10 Years, 9 Months ago  
Ok.....

It appears that if I followed directions better I would have saved myself a lot of problems.

I was setting the float to the front of the carbs mating surface. At DocShadow's advice, I took the carb back off and reset the float in a vice and guaged the setting by the back of the carbs mating surface. Problem resolved. Bike accelerates fine all the way through 5th gear. I probably need to raise it a bit higher though. When accelerating wot at the top of 5th it will act like it is running out of gas. Being that I dont need to run it like this with every acceleration, I will probably wait till I have a reason to pull the carb off again.

Thanks all for the various comments. The help was greatly appreciated.

Huygens....<br><br>Post edited by: huygens, at: 2007/05/26 11:59
 
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#27991
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 9 Months ago  
If you are running a Mikuni 175 main then you're probably correct, you could bump the float up 2 mm or so.

If you're running a DJ 175 main then try a 180.

Doc
 
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#41559
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 5 Months ago  
I know this is an old thread, but I just have a question. If I do this mod, do I have to go without the pump. What if I use the 2.5 and keep the pump? Thanks guys.
 
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#41561
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 5 Months ago  
Thats fine the float controls the amount in the bowl the needle controls the speed ...Coug
 
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Last Edit: 2007/09/17 18:37 By Cougar.
 
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#41564
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 5 Months ago  
Thx for the quick comeback. Is this mod worth the doing. I have tried dialing in my PMS, but I still get a carb cough, goosing at 70mph and above while using 1/4 throttle. I had it jetted at the stealership so I don't know the size of needles. I know what they did has gotten rid of the backfire through the exhaust. I have had to run with slight &quot;choke&quot; since they jetted it. I thought I was lean and Doc suggested backing out the PMS. I did about 1/2 turn and the number three plug fuel fouled. I am at my wits end and am ready to beg Yamaha for a kit to outfit my RS with FI . I am not mechanical but I have you guys and a repair manual, so I am willing to go this. That is, when I find the Suzuki part.
Thx
 
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#41576
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 5 Months ago  
grgj258 wrote:
I had it jetted at the stealership so I don't know the size of needles.

You should really find out what your jetting is before you try fixing something that might not be the problem. My .6 cents anywho.
 
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#41578
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Re:Change the Float Bowl Needle Valve (and lose yo 10 Years, 5 Months ago  
The larger float needle valve Suzuki part # 13370-08F50 can be found here ...at checkout use the minus sign to bring the # of needles to 1 @33.47 a per valve when you check out reduce the nuber of valves by using the - Minus sign..... looks like they are making you buy 4 at a time...Coug

http://www.motogrid.com/pages/parts/viewbybrand/1/default.aspx
 
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Last Edit: 2007/09/18 16:19 By Cougar.
 
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