Float adjustment

[wrscomncents]

I would appreciate any ideas on my current issue. I just reinstalled the carbs after having a problem with two cylinders not firing. That issue has been solved but here is my current problem. The bike fires right up. Idles perfectly, has great response when you crack the throttle. When I get it on the street it takes off like a bat out of hell through the first couple of gears but by the time I get to third gear and really crank the throttle it starts to bog down as if its running low on fuel. My theory was that the floats were to high and the bowls were running dry. So I removed the carbs again and rechecked the floats. They seemed to be within specs so I decided to use the tube method to set the floats. Here's the strange part. It seems that no matter where I set the floats the fuel level in the tubes never moves any higher or lower than the bottom of the edge of the carb body. According to the service manual the correct adjustment is supposed to be 13-14mm above the edge of the carb. I intentionally bent one of the float tabs to full rich and the fuel level still stays at the edge of the carb. So I guess I have two questions here I hope someone else has experienced:1. Any idea what could be causing the acceleration problem I'm having? 2. Has anyone had experience using the tube method of adjusting the floats? Here is a few things I have eliminated. The fuel tank vent is not plugged. The carb vent tubes are not plugged. I can't seem to find any vacuum leaks in any of the hoses that I have checked but if there is a another way to check for vacuum leaks I would love to get any info. Any info at all would be helpful. I would love to solve this and not have to take it into the shop. Thanks.

[BlueSky]

Is the fuel filter clean?

[Patch]

Fuel filter

Air filter ( the whole air box needs proper integrity)

Fuel pump pressure

 

I always set the floats while open. Also submerge them looking for bubbles. Now I have found on the "gen 1.5" that the floats can jamb, so I check this before final set of the floats by being a little aggressive with them through the expected travel. The ears that the bar travels through ware a bit or the bar does? Once I found that the float body swelled a bit, not sure what causes it? However I will note that one of the 2 bikes we ran last year had seen a lot of pure seafoam sitting in in the bowls, someones effort to avoid pulling the carbs.

[Patch]

And your needles/ diaphragms and cap O-rings?

[M61A1MECH]

Also check here in the Tech Section for 2nd Gens, for an optional way to set the floats.

http://www.venturerider.org/forum/showthread.php?24246-Set-the-Float-Levels-on-QuickSilver

 

What air filters are you using? K&Ns can cause a lean condition some times.

Have the air boxes been modified? I made the mistake of installing K&Ns and opening up the air boxes on my 07 and it would bog down terribly, I ended up shimming the needles values out by one washer and going back to stock air boxes with the K&N filters.

[wrscomncents]

Is the fuel filter clean?

 

Bluesky

 

Thanks for the response. I should have stated some of the other things that I have done to the bike. I bought this bike used and it didn't seem to be treated to well although there were only two previous owners. I installed new plugs, new air filters, new fuel filter and rebuilt the carbs. Also adjusted the valves. The bike is a 1999 and only has a little over 24000 miles on it.

[wrscomncents]

Fuel filter

Air filter ( the whole air box needs proper integrity)

Fuel pump pressure

 

I always set the floats while open. Also submerge them looking for bubbles. Now I have found on the "gen 1.5" that the floats can jamb, so I check this before final set of the floats by being a little aggressive with them through the expected travel. The ears that the bar travels through ware a bit or the bar does? Once I found that the float body swelled a bit, not sure what causes it? However I will note that one of the 2 bikes we ran last year had seen a lot of pure seafoam sitting in in the bowls, someones effort to avoid pulling the carbs.

 

Steven

 

Thanks for the response. I have not checked the fuel pump. I know that it is working because I hear it and I can also watch the fuel filter fill. I moved the fuel filter to under the seat following instructions from another post here. I'll have to check the pressure on the pump. Thanks for that idea. When you say that you set the floats wide open are you saying that they are set not to shut off the needle valve until they are at the full up position? I'm about to take it out again after checking all the floats. If the response hasn't changed I will pull the carbs again and check the float travel. Thanks again.

[wrscomncents]

Also check here in the Tech Section for 2nd Gens, for an optional way to set the floats.

http://www.venturerider.org/forum/showthread.php?24246-Set-the-Float-Levels-on-QuickSilver

 

What air filters are you using? K&Ns can cause a lean condition some times.

Have the air boxes been modified? I made the mistake of installing K&Ns and opening up the air boxes on my 07 and it would bog down terribly, I ended up shimming the needles values out by one washer and going back to stock air boxes with the K&N filters.

 

M61A1MECH

 

I'm am just using standard air filters. Both sides are new. Nothing has been modified. Thanks for the link.

[Patch]

The floats I set while I have the carbs open!

Before I set them (regardless of what carb I am working on) I make sure that the floats will not bind in any position!

Then I set for the recommended float height.

 

If you have the carbs off again? Do this: place your hand over the intake and spin the engine no more then 5 turns, repeat on all four intakes.

Does the vacuum draw hard and hold your hand firm? this will hint at the "tightness" of the low pressure/vacuum.

 

The above is just my way, you may not be comfortable doing this.

 

What about the slides? clean? are the ports on the casings developing vacuum, check with your thumb while cranking.. There's a small o-ring on one of the corners when the slide caps are off you should see easly..

[Patch]

just taking a quick look and found this, you may have allready read..

 

http://www.venturerider.org/forum/showthread.php?24246-Set-the-Float-Levels-on-QuickSilver

[wrscomncents]

The floats I set while I have the carbs open!

Before I set them (regardless of what carb I am working on) I make sure that the floats will not bind in any position!

Then I set for the recommended float height.

 

If you have the carbs off again? Do this: place your hand over the intake and spin the engine no more then 5 turns, repeat on all four intakes.

Does the vacuum draw hard and hold your hand firm? this will hint at the "tightness" of the low pressure/vacuum.

 

The above is just my way, you may not be comfortable doing this.

 

What about the slides? clean? are the ports on the casings developing vacuum, check with your thumb while cranking.. There's a small o-ring on one of the corners when the slide caps are off you should see easly..

 

So I just got back from a ride and unfortunately I'm still having the same issue. I'm almost sure its a fuel starvation issue because it runs great going through the first two gears and then the issue begins. Also getting some backfire on deceleration. I am pretty sure it is not an exhaust leaking issue. I replaced all of the exhaust seals. It is very frustrating because it runs so good before the issue occurs. Thanks for the link I did read it already. M61A1MECH sent it to me earlier. Funny thing is it is exactly the same way I set my floats. I will try to check for the vacuum as you suggested. I will also check the floats to make sure they are not binding. Slides are clean and all are moving when throttled up. I'm not sure which ports you are referring to but I will look for them when I have it apart again. I am still baffled by the fact that the bowl level stays the same when using the tube test no matter where I set the floats. It seems like the level should change. Thanks for your advise.

[Patch]

You could check pump volume.

When you say it runs well in 1st and second, it rpm and throttle position that matters right.

 

Remember mine is a 91, and I'm not sure what yours is, I checked your profile? Are you running stock setup?

[Patch]

here, you likely have a manual but so w are on the same page start at 6-11

 

http://www.werder.ee/Manual/XVZ1300.pdf

 

Rule each one out starting with the position sensor

[sldunker]

Make sure your lower cowlings are on. If these are off you will have all kinds of problems with air delivery. Had a member on here not to long ago with a similiar problem. He did not have lower cowlings on when he was testing.

[wrscomncents]

You could check pump volume.

When you say it runs well in 1st and second, it rpm and throttle position that matters right.

 

Remember mine is a 91, and I'm not sure what yours is, I checked your profile? Are you running stock setup?

 

Yes everything is stock. It's a 99. It runs great up through second and into third. If I don't get on the throttle it will run through all the gears. If I throttle up through the gears it will start to bog down by the time I reach third. I then have to let off the throttle for a bit and let it catch back up. I'm assuming the carb bowls are refilling at this point. This could be a bad assumption on my part but it's the only thing that makes sense to me. If I then wait a bit and jump on it again it will do the same thing over again. Like I said if I just apply somewhat normal throttle it will run through all the gears but there is a bit of missing at times like the fuel flow isn't keeping up with the burn rate.

[Patch]

and the air flow setup is all together, nothing left out?

 

So lets follow the trouble shooting guide checking off one thing at a time as you move through it, unless someone has better input..

 

When your ready

[wrscomncents]

Make sure your lower cowlings are on. If these are off you will have all kinds of problems with air delivery. Had a member on here not to long ago with a similiar problem. He did not have lower cowlings on when he was testing.

 

[h=5]sldunker[/h]Thanks for the heads up on that. I have been test riding without the lower cowlings. I'm not sure that would have the effect on the bike that I'm having but I guess you never know. Maybe I'll put them on tomorrow and give it a run.

[wrscomncents]

sldunker

 

Thanks for the heads up on that. I have been test riding without the lower cowlings. I'm not sure that would have the effect on the bike that I'm having but I guess you never know. Maybe I'll put them on tomorrow and give it a run.

 

So I just went out and checked how the lower cowlings attach to the bike and they do cover the air intakes on the air filters. Not having them attached would act like a ram air induction. Not sure what effect that would have on the engine but it may be disruptive. I will put them on tomorrow and give it another run. Let you know how it goes. Thanks

[sldunker]

I think you are going to be surprised!

[Patch]

"Air filter ( the whole air box needs proper integrity)"

 

YOU ARE FIRED!

[Patch]

"So I just went out and checked how the lower cowlings attach to the bike and they do cover the air intakes on the air filters. Not having them attached would act like a ram air induction. Not sure what effect that would have on the engine but it may be disruptive. I will put them on tomorrow and give it another run. Let you know how it goes."

 

So you were right kind of, you were running out of gas compared to the throttle plate position.

 

If you have experience with say Holly’s or slide carbs you have just experienced Constant Velocity and its venturi process. The CV needs a constant velocity and the tuned balance that the air box provides. So because you in effect unbalanced the air stream pressure, the venturi was incapable of opening the mains.

This is why I was asking if you could feel vacuum at the diaphragm/ which is a vacuum actuated piston that pulls the main tapered needle up the main jet.

 

All is well that ends well;)

[Marcarl]

If all that doesn't work might I suggest to change the fuel delivery lines, being that they are 10 years old there may be some restriction going on.

When you set the floats are you sure that the drain screws are properly open? I know, stupid question, but stranger things have taken place in my life.

[wrscomncents]

"So I just went out and checked how the lower cowlings attach to the bike and they do cover the air intakes on the air filters. Not having them attached would act like a ram air induction. Not sure what effect that would have on the engine but it may be disruptive. I will put them on tomorrow and give it another run. Let you know how it goes."

 

So you were right kind of, you were running out of gas compared to the throttle plate position.

 

If you have experience with say Holly’s or slide carbs you have just experienced Constant Velocity and its venturi process. The CV needs a constant velocity and the tuned balance that the air box provides. So because you in effect unbalanced the air stream pressure, the venturi was incapable of opening the mains.

This is why I was asking if you could feel vacuum at the diaphragm/ which is a vacuum actuated piston that pulls the main tapered needle up the main jet.

 

All is well that ends well;)

 

 

"Air filter ( the whole air box needs proper integrity)"

 

Steven

 

Your right I suppose the whole air box does not have proper integrity with the lower fairings off. I honestly never thought of it. I actually was thinking that the air inlets were exposed to the air even with the fairings on. My bad. Anyway I am going to put them back on at some point today and see how that goes. Will be great if that is the problem. I will let you guys know. At any rate I appreciate all of the input from everyone here.

[wrscomncents]

If all that doesn't work might I suggest to change the fuel delivery lines, being that they are 10 years old there may be some restriction going on.

When you set the floats are you sure that the drain screws are properly open? I know, stupid question, but stranger things have taken place in my life.

 

Marcarl

 

Actually I have replaced all of the fuel lines. When you say are the drain screws properly open when I check the floats I am assuming you are referring to when I'm using the tube method. If so yes I have opened them to the point where I get fuel from them just to be sure. I'm still baffled by the fact that there is no change in the fuel level no matter where I set the floats. If I end up having to pull the carbs again I am going to run a level across the top of bowls and see if it is possible for the fuel level to even go any higher. Have you ever used this method?

[Patch]

Well its all part of the learning curve!

 

I've not been a fan of check the floats in that manner, but is a quick way if you are looking for a particular problem. Key on!