Carb butterfly sticking..other issues

[elianator]

Hello everyone,

I have been a bad boy and let my 2004 Katana 600 sit too long and had issues starting. Would only start under choke so...been there... done that... and started my 2nd rebuild. The first one went really well and this one seemed the same. Carbs soaked in Berryman...Put everything together and I could not get the throttle adjusted correctly. The throttle was slow to return. Checked cables and looked ok. Even choke cables were slow to return. Decided to take carbs off again and then whammo. One of the two carbs (the ones without a return spring, would not open and close easily. Lubed one up a little and got better. Another carb, spring loaded, was basically stuck, got it to move better. Took them all apart again and will try and soak them for 30 minutes to see what happens. Why did this happen? I actually put the carbs back on the bike a few days ago, no throttle issues, and then a few days later and no worky...Love my bike, even waiting on repainting, but she's fighting back. Choke issues resolved quickly.....wire brush on drill to polish and in opening and smooth as silk. The only other issue was that when I backed out the pilot screws, they almost all lined up exactly....I mean they all looked like they were in the same position (lets say 10 o'clock) but one did not.

[RobertTravis]

Why did this happen?

My theory would be the Berryman took off all the lube and you reassembled it in dry. Not sure what the recommended lube is for that...whether it is silicone grease or vaseline...but dry on dry is bad because it will gall the aluminum - effectively making the bore smaller than it should be and prone to seizing.

[92xjunker]

I use graphite based lube.

[elianator]

I had done this one time before and never had this issue. I soaked the two carbs in Berryman again, one without a return spring for 30 minutes and it actually freed up like new...the 2nd one did have a return spring and it took longer to free up, but it did..Working perfectly now....very loose so they snap back hard.....lubed them up a little to be safe and cleaned it up. Visual sync completed and tps set to 3.8k with full open throttle...waiting on putting it back on and gassing up tomorrow.

[Kreylyn]

Berryman's will leak out/remove some oxidations. That includes vibration oxidations that will form hard smooth surface, allowing things to pivot a little easier but won't further oxidize to cause tolerances to be too tight and freeze things up.

That said... if the oxidization layer is removed, then it will reform as it sits. If it's sitting still, that layer may continue to grow and reduce those tolerances. Simply put, the cleaning would have removed the old thinner layer, and the new oxidization re-formed thicker.

Oxygen is what catalyzes the oxidization. So not only will lube help in the short term for making things slippery, but it also reduced the oxygen and decrease the amount of oxidation that forms over all, thus keeping clearances looser.

Or... something.

Krey

[elianator]

Well, on point as usual in this forum. It ends up 90% sure that it is rust/oxidation. I put everything back on the bike and was putting it back together slowly. Checked again and the butterfly/throttle getting stuck. Used my ultrasonic (I forgot I had it) and then came the rust coming out. Unfortunately, it is all inside of the carb and that rod is not replaceable. I did find something to try and save my carb set since it is the original one for my bike, Metal Rescue. It supposedly only attacks rust. I soaked it in this solution for around 3 hours and not only was all of the visible rust gone, it now opens and closes with even less resistance than the last time I did this. I will lube it some as well and maybe by this weekend, I will know where I stand with this or if I have to buy a new set of carbs.

[Kreylyn]

Well, on point as usual in this forum. It ends up 90% sure that it is rust/oxidation. I put everything back on the bike and was putting it back together slowly. Checked again and the butterfly/throttle getting stuck. Used my ultrasonic (I forgot I had it) and then came the rust coming out. Unfortunately, it is all inside of the carb and that rod is not replaceable. I did find something to try and save my carb set since it is the original one for my bike, Metal Rescue. It supposedly only attacks rust. I soaked it in this solution for around 3 hours and not only was all of the visible rust gone, it now opens and closes with even less resistance than the last time I did this. I will lube it some as well and maybe by this weekend, I will know where I stand with this or if I have to buy a new set of carbs.

What rod is not replaceable?

Krey

[elianator]

The rods that the butterfly is attached to.....A couple of weeks ago, started up nice, throttle response smooth and strong, but could not get an idle. Made adjustments and still cant get it to work right. Cleaned pilot circuit for the 4th time. I am beginning to believe that the Metal Clean I used got all of the rust out, but that it took some metal with it, if you know what I mean.. and there are rusted away pieces inside of the body that are either bad or gone. Will try and few different settings on the pilot screw... started at 2.5 with above signs and then to 2.75 and now will try and 2 and work my way up. BTW, with our screws..is less turns more air or more fuel.

[Kreylyn]

The rods that the butterfly is attached to.....A couple of weeks ago, started up nice, throttle response smooth and strong, but could not get an idle. Made adjustments and still cant get it to work right. Cleaned pilot circuit for the 4th time. I am beginning to believe that the Metal Clean I used got all of the rust out, but that it took some metal with it, if you know what I mean.. and there are rusted away pieces inside of the body that are either bad or gone. Will try and few different settings on the pilot screw... started at 2.5 with above signs and then to 2.75 and now will try and 2 and work my way up. BTW, with our screws..is less turns more air or more fuel.

You are not in the US are you? So, not a US model bike?

The a/f screws for non US models should start much lower... like 1.5 turns out.

The steel butterfly linkage rods should pull right out if you take the butterfly out + take off the nut on the end of the rods. You can then clean them up and treat them with an anti corrosion solution to prevent them from rusting in the future. Clean up the areas they insert in, and then lube the felt gaskets that go on them to help keep them working smooth in the future.

Krey

[elianator]

Thanks for getting back....life and delays. Finally brought over someone that knows far more than I do about this. The bike is still not running right, but as many of you suspected, all signs pointing heavily towards vacuum leak or air setting of some sort. With an extra set of hands, started up the bike, would idle ok but still stalling on throttle. Then my buddy shoved his hand up my old Kat's skirt (right in the air filter opening) and whammo!!! Idle smoothed out and could rev it all the way to 11k. Will look at replacing all of the orings on the intake tomorrow (if I find them) and hopefully I can take some pics and thank everyone. My buddy said that this was a tricky fish and he was expecting something to be backwards, but I told him how well read I am, especially from people on this site.

[elianator]

Hey guys....I have never had something kick my ass so hard like this. Still stalls and WOT and wont get past it. Not much has changed. Changed all of the o rings on the boots for the intake side of the carb and still same problem. Sprayed every junction and I can't find a leak anywhere!! When I put my fingers in the air filter opening and partially obstruct it, the bike roars back to life, throttle smooth to WOT and no backfiring most of the time. Help!!! What else could this be? Does this bring me back to something like float height even though I double checked them and now have two sets or carbs, BOTH were doing the exact same thing.

[ZookRick]

Do you have a stock airbox and stock type paper filter?

[Kreylyn]

Partially obstructed carb ports would reduce the amount of fuel flowing through causing the carbs to run lean. Putting your hand over the intake decreases the air flow and increases the pressures pulling the fuel out of the carbs = richer mix.

My expectation is the carbs are still not fully cleaned. Specifically I'd check the ports internally from the air jets on in. A partial blockage between the main air jet and the emulsion chambers would cause problems.

Also just occurred to me... double check you put the needle jets in the correct way. It's not hard for someone to flip them upside down, and that would cause serious WOT running issues.

Krey

[elianator]

Do you have a stock airbox and stock type paper filter?

I have both oem and k&n. Initially, K&N has been in for years now with no issues. Switched back to the OEM and the same symptoms.

Partially obstructed carb ports would reduce the amount of fuel flowing through causing the carbs to run lean. Putting your hand over the intake decreases the air flow and increases the pressures pulling the fuel out of the carbs = richer mix.

My expectation is the carbs are still not fully cleaned. Specifically I'd check the ports internally from the air jets on in. A partial blockage between the main air jet and the emulsion chambers would cause problems.

Also just occurred to me... double check you put the needle jets in the correct way. It's not hard for someone to flip them upside down, and that would cause serious WOT running issues.

Krey

I had seen the needle jet question someplace else on the internet and a person discussing how the jet should not protrude through the hole inside of the main chamber, yet I always recall them to be protruding through a little. Do I have these backwards? Every picture I could find on these carbs seem to have them poking through. If you reverse it, it does not go through, but it does not seem to seat properly.

[elianator]

BTW.....I just aw a video on youtube of a Katana with no airbox on and the guy was revving it up just fine...If this is true and I find no air leaks at the intake, doesn't this make it almost certainly something internal? Will keep trying in the meantime.