Carburetor Cleaning & Tuning 101
Member
Joined: Apr 2012
Posts: 34
Likes: 0
From: Phoenix
JD - This sounds like your air valve may be inop or an air hose is leaking. Check this forum for the 'air valve delete' mod.
Also, I had similar symptoms and when I pulled the fuel hose off I noticed the inside liner of the fuel hose was sliding down and bunching up causing a restriction in the line.
Let us know.
BTW, I have a spare carb set for sale. Is set to pass AZ emissions test.
Also, I had similar symptoms and when I pulled the fuel hose off I noticed the inside liner of the fuel hose was sliding down and bunching up causing a restriction in the line.
Let us know.
BTW, I have a spare carb set for sale. Is set to pass AZ emissions test.
Thread Starter
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Senior Member
Joined: Jul 2009
Posts: 769
Likes: 1
From: Pittsburgh, PA
92 F2, 2,300 miles, sat for 8 years with gas, yuck. Tank was presurred cleaned by a radiator outfit and sealed. Carbs removed via great article here. I replaced the pilot jets and cleaned everything else. Bike started, ran perfect for 6 miles. Idled and was responsive, literally ran like a brand new bike. Then after steady cruise around 55 for 4 miles or so it acted like it was running out of fuel. Took it home and took everything apart. Needles, jets, floats, everything looked fine. There was no sediment or anything in carbs. I removed the pilot jets and they looked clean. Put everything back together with an in-line fuel filter. I've ridden around 100 miles. The bike starts easily with choke but runs rough. After a minute or two without choke it idles reasonable well. Accelerating with partial throttle the bike seems hesitant. Somewhere between 3,000 and 4,000 rpm the bike seems to start running better and pulls reasonable well and generally sounds okay. If I run around 5,000 for more than 3 or 4 miles the bike eventually acts like its running out of fuel and dies. Today, after sitting by the side of the road for about 5 minutes, the bike started with the choke. I immediately shut the choke and it idled fine. I rode home (10 miles) not going over 4,000 rpm. The bike ran rough but I made it home. The weird thing to me is the first time out after new jets the bike idled and ran like brand new. The floats are not adjustable.
If that checks out, check each spark plug for signs of flooding or being too lean. Do this immediately after it stalls. I only say to do this in case you are not too savvy with your bike sounds and behaviors. If you are 100% sure its running out of feel, then you have a fuel problem. Engines react different when they run out of fuel, run on 3 cylinders, run lean or rich, etc.
A vacuum leak is a possibility, and what ReconMan said is also a possibility. Check your hoses to make sure nothing is kinked.
Easiest way to figure out a problem (beyond checking the immediate obvious causes that you can see, like a kinked hose) in my opinion is to check things that leave signs like your plugs and the bowls. Otherwise you are just guessing.
Junior Member
Joined: Oct 2012
Posts: 18
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hello i have recently done a carb cleaning and rebuild. I can not get the bike running after reassemble, i have tried everything. i noticed now after taking the idle adjustment screw out one by one that the #2 carb screw has gas on it. where did I go wrong? any suggestions will help.
Thank You
Thank You
Junior Member
Joined: Apr 2013
Posts: 17
Likes: 4
From: Modesto, ca
I just installed a jet and cleaned everything. Got carbs hooked onto bike, fire it up...after a few minutes i blip the throttle and it revs and stays revved. Throttle cables are fine. What can it be?
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Senior Member
Joined: Jul 2009
Posts: 769
Likes: 1
From: Pittsburgh, PA
Idle set too high? Choke stuck? You want the carbs to be adjusted so that the bike requires the choke to start, then after it warms up you have to shut the choke off.
Junior Member
Joined: Apr 2013
Posts: 17
Likes: 4
From: Modesto, ca
Thanks for the reply. How would i adjust it to make sure it needed the choke to warm up? I have the idle set right, choke is closing when needed. Is it possible that the fuel mixture screws might not be at the correct setting?
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Senior Member
Joined: Jul 2009
Posts: 769
Likes: 1
From: Pittsburgh, PA
yeah, the pilot screws may be out too far. They should be somewhere around 2 and a half turns out, or 2 and a quarter, not sure exactly, but around there.
Does your bike require the choke to start? Or can it start with the choke off?
If you dig the carbs out, double check to make sure your choke is pulling the lever thing on the carbs, and that the lever slides freely back and forth.
Does your bike require the choke to start? Or can it start with the choke off?
If you dig the carbs out, double check to make sure your choke is pulling the lever thing on the carbs, and that the lever slides freely back and forth.
