Float level problems

[06VMAXIMUS]

I am having to measure precisely 17 mm from the bottom of the carb to the end of the float with the carb upside down .

Maybe I'm reading this wrong, but I think you might be measuring the wrong way. IIRC, you should measure 1.115 from the bottom of the carb to the end of the float. That will give you the 17mm wet level when assembled. Review this post to confirm you are indeed measuring the correct area and the correct dimension:
http://www.vmaxforum.net/showthread.php?t=1427

 

[[email protected]]

DHC,

Seems you've been battling this for awhile now. I highly suggest you take some pictures of what you are seeing, and how you are measuring your floats. Maybe we can help spot the problem.

 

[dhc1975]

Sorry about the delay guys, I was trying to send the pics from my phone while I was on the road(truck driver), but I am back home now here's pics of my wet level reading, dry reading, and caliper reading.

 

[dhc1975]

Closer view of carb.

 

[naughtyG]

Well looking at your pics I agree that the closeups on the carbs show the floats seem to be just ever so slightly low - as in 'rich' since they're upside down.

Your dry measurements also look ok. I think the problem is your wet reading.

A few things to try:

- I assume the bike's on its center stand? Service manual says use a jack under the motor to make sure it's absolutely level - are you? Is your bike lowered either front, back or both?

- have you made sure to warm up the engine thoroughly before taking the readings?

- try taking readings using just clear tubing held against the center mark - any change?

- how much are you loosening the drain screws? Are they in good condition? Any leaks at the screws themselves?

- what your altitude, any chance that could affect anything?

Also, how does the bike run? Have you tried going for a good ride, then after 15-20mns of riding, hit the killswitch while cruising, come to a stop and pull your spark plugs. What do they look like?

 

[dhc1975]

The black tape on the float gauge is 17mm from top of index line.

 

[dhc1975]

I had the carbs on the bike, even put a level on them to make sure they were level and they were. I rode for two days with carbs on bike at this setting. I checked level after 35 mins of riding and it was showing what is in the pic. The spark plugs were showing lean conditions with white dry electrode and the bike would pop some in low speed and idle along with a little stutter. I've also been checking the wet levels on bench with level surface and still get same reading. The bike has not been modified as far as low or high in front or back and is level on mainstand. I open the drain screws all the way and allow all the fuel to drain into the gauge and the drain screws do not leak. I live in Savannah,Ga. which is precisly 46 ft. above sea level.

 

[naughtyG]

This surely is VERY odd. Everything seems fine, but the result is not.

Have you tried bending the tabs as far as they'll go to try and reach 17mm? Also one last test - take your floats out and let them soak overnight in fuel, just to make sure they float properly and aren't punctured or gone porous as I remember someone saying some time back. I can't see that happening to an '01, but you never know.

Other than that maybe try asking Sean or Kyle or anyone here who may have a set of floats for oyu to swap/try.

I'm at a loss as to what else to suggest. Anyone else?

 

[[email protected]]

I tooka quick look at the pics and do not see anything out of the ordinary...Except for the wet levels. The way he is measuring looks correct and the dry levels look pretty close as well. I am not familiar with yamaha's tool that he is using but I cant see it making any difference. I typically just push a piece of clear tubing into the carb drain, mark it at 17mm from the end and turn the key on/off a few times untill the level quits rising.

 

[06VMAXIMUS]

Dry setting looks good to me! Are all of your jets stock? What are your A/F screws set at? Any mods, or all stock bike?

 

[dhc1975]

okay, I bent the float bowl tangs in as far as they would go and I finally reached the 17mm mark on the dot, but that makes no sense why I would have to bend them in all the way just to get that reading, maybe the floats are bad.

 

[dhc1975]

Stock jets and block, a/f screws were at 2 1/4 turns out,stock setting, no mods just stock bike. The bike had some older ufo pipes on it that were extremely loud, I changed the pipes to stock, and in the carbs only the jet needle, and main jet had benn changed which I ended up putting back to stock.

 

[dannymax]

As mentioned in post #20, if the seats don't protrude far enough into the chamber this can happen. Some a/m seats don't shoulder properly in the carb body and it screws up the settings big time.

Has anyone changed the seats/needles?

 

[dhc1975]

As far as I know the float needles and seats have never been changed, I wondered the same thing, unfortunatley there are not stanped numbers on the seat or needle like there is on the jets. I measured how far out the seat is from the carb and it is roughly around .165". I don't think I am going to be able to get the carbs rich enough to reach the spec window. What do you guys think, get it close to spec on wet, go up from 152.5 main jet to 155 or 160, 3 turns out on a/f screw and balance carbs and this should take care of the popping and stutter on low speed idle circuit and lean condition?

 

[tugla]

you should be able to get it right on the money..... well thats just me im never happy if its not right. are you wet setting them on the bike still or on the bench wet set? its bench wet set and get it right on and then put on the bike you should be golden....

 

[06VMAXIMUS]

Increasing the main size will richen up the top, not the low end. I had lean popping on mine after adding the marks pipes...until I shimmed the needles, and it took care of it. I would try playing with your mixture screws and maybe shimming the needles first. I'm surprised your having problems with everything being stock.....sounds like something just isn't right.

 

[naughtyG]

OK I have a suggestion for you: study the attached pictures. In the first one notice the BIG difference in needle seat height between the left and right carbs (arrowed in red), and the resultant difference in the bending of the float tabs to reach the right level.

The second picture shows one carb from my old '86, and how I adjusted my floats on the bench (I didn't even measure, just lined up the metal circle marking edge with the inside curve of the float, and they were almost bang on 16mm).

I think you should pull out your needles, and then see if your needle seats will move at all? If able, maybe try very carefully pushing them further into the carb bodies? Do take advice from carb gurus such as Maleko and Sean Morley before doing this though, I've never done it myself.

One last thing - there's a tiny springed nipple in the needles themselves. Are you taking your measurement with that nipple compressed or not?

If I remember right, I adjusted mine dry with the carb on its side, and the float just resting against the needle. I think the lil' nipple was compressed.

 

[sdt354]

I'm about to do Marks carbs.Waiting on parts and a free day. On a wet check before doing any work(I like to know before I open them up) 2 carbs are high. One about 12 mm.The other 15mm. This bike is fairly new too. 2 are 17mm.The 15mm carb is a smiggion adjustment. I have a feeling you can't count on the factory to set them perfect. I'll be interested to see where the floats are at on the high level carbs in relation to the casting circle.And the seat hights. I'll bring the camera too.
Steve-o

 

[speedcostsmoney]

TRIED 1.115 inch from the inside of carb NOT GOOD if you check you will notice that the float plunger stays close to the closed position, so you will get very little gas coming in, my VMAX did not like this setting problem starting the bike , so installed the float height to 1.030 inch from the outside of the carb just before the float touches the jet block ,you get maximum gas in the float bowl running 172.5 mikuni main jet otherwise if i gun it WOT let go of the gas, then punch the gas WOT again the engine does not get enough gas, this set-up works fine but guess it depends if you drive nice and slow or if you drive the VMAX HARD LIKE YOU JUST STOLE IT

 

[maleko89]

Damn, that's a big ass main jet! 8 sizes more than stock! I set mine to 1.125 (17 mm) and it doesn't cut out at all. Dyno showed 133 rwhp at 10,000 rpms. Just curious, why would you lay off WOT and then immediately do it again? Wheelie?