Crap... more help needed:float adjustment

[mercdude63]

Ok, so i think i officially hate the Clymer manual. So i go to adjust the float bowls... to heighten float level=lower fuel level=lean However, the manual doesn't make clear how to measure the float height. Says something about measuring from the base of the carb to the top of the float right when it pushes the needle. I'm wondering, pushing it up, or down... depends if you are talking about the carbs being rightside up or down.

How do you adjust the float level to more lean? I assumed that if you bend the tongs down when looking at the carbs upside down that it would do this. Am i correct???

Anyways, pretty sure mine was at 13mms stock and i raised it to 15mms (i think the needle/seat is getting worn out that's why it was so low) This should be enough to make my bike significantly leaner, correct?

jon

[Kerry]

Here is the page from the Haynes manual.  Steps 6 and 7 are the most relevant, along with diagram 9.7.  The spec for the float height measurement is 14.6mm +/- 1mm.

http://www.bbburma.net/Scans/Haynes_FloatHeight_FullPage.jpg

[Rema1000]

Anyways, pretty sure mine was at 13mms stock and i raised it to 15mms (i think the needle/seat is getting worn out that's why it was so low) This should be enough to make my bike significantly leaner, correct?

It works like a toilet tank float valve: the float rises on the gas in the bowl, and when it gets high enough (which in this case means near enough to the bowl-to-carb gasket), then the float pushes on the float needle, via the tongs, and the needle is pushed up to stop the flow of fuel.  What you are adjusting, is how long the tongs are.

So if the float is adjusted to be further from the carb body, then it will take less fuel in the bowl, to push the float high enough to shut the fuel valve.  The result is a lower fuel level in the bowl, and the bike should run leaner in some circumstances.  In practice, the difference is supposedly more pronounced under specific circumstances, like sustained WOT and hard cornering.  

Also, I don't think a 2mm difference is going to be too noticeable; at 13mm, you were 0.6mm below spec on the low side, and now you're in spec.  So if your goal is to put it in-spec, then congratulations, it sounds like you've done that.  Adjust the idle and idle mixture, and you're done .  

But if you were expecting a 2mm difference in float height to significantly change mixture at idle, then I don't think you're going to see that.  I was once 6mm out of spec (too rich), and the bike seemed to run fine.

Also, regardless of how you measured it with the carbs off the bike, be sure that you measure using the U-tube method.  Measuring the float height with a ruler is a very touchy process, and your results can be swayed by how you hold the carbs, whether you sight through one eye or two, etc.  The U-tube method is consistent, and may show that you bumped the tongs as you reassembled the float bowl, etc.

[mercdude63]

Thanks kerry for the haynes manual, that makes MUCH MUCH MUCH MUCH MUCH (can i emphasis MUCH more???) SENSE. F* the clymer, i'm getting a haynes.

Onto the problem at hand... how far should you be bending the little tabs? I bent mine about 2-3mms at least to get the float height to what i set it at. I'm starting to think that reason it was out of adjustment was because the float needle+seat (aka the little plunger and seat) is worn out and is sitting farther down.

My specific problem comes from DJ saying i should increase the float level 1-2mms to make the carbs run leaner in WOT operation because i can't get the carbs to run lean enough with just raising the clip position on the main needle. I am sure they assumed that my carbs were running within spec... so maybe i should go up another 1-2mms?

Where do i get on of those tube dealios? I've never heard anything like before... how do you use it? ... Looks like you unscrew something and check the fuel level as it fills up the tube... should only go as far up as the float level inside is set, correct?

just to make sure... bending the float bowl tabs down so they are closer to the plunger is setting it higher, correct?

Jon

[Kerry]

Thanks kerry for the haynes manual, that makes MUCH MUCH MUCH MUCH MUCH (can i emphasis MUCH more???) SENSE. F* the clymer, i'm getting a haynes.

Make sure you post your thoughts after comparing the two.  I'm sure people are tired of hearing mine all the time.    

how far should you be bending the little tabs?

Well, enough to get the desired measurement.  :mrgreen:

so maybe i should go up another 1-2mms?

Can't help you there.  With the DJ kit thrown into the equation, you may have to be the guinea pig and let US know when you get it figured out....  :dunno:

Where do i get on of those tube dealios? I've never heard anything like before... how do you use it?

See my Float Height Check page.

Looks like you unscrew something and check the fuel level as it fills up the tube... should only go as far up as the float level inside is set, correct?

Yep, that's the gist of it!

just to make sure... bending the float bowl tabs down so they are closer to the plunger is setting it higher, correct?

Hmmm.  Well, it will make for a lower measurement as shown in the Haynes manual, but it will result in the fuel level being higher in the float bowls.  I'm not sure which one you're after....

[Rema1000]

how far should you be bending the little tabs? I bent mine about 2-3mms at least to get the float height to what i set it at.

The tabs act as spring/levers against the float.  The adjustment is not linear.  I believe that I was able to change the float height by 5mm, but only needed to bend the tab a little less than 1mm to do so.  Obviously, I didn't bend the tab 5mm, because the little tab is barely ever 5mm long (are we talking about the same tab?).

The process I used was: check float height using the u-tube method, and note which direction the height needs to move, and how many mm; then remove the float bowls and measure what I think the measurement is (using the Haynes method), just as a reference point.  The push lightly on the tab in the direction I want it to go, then reassemble and re-check using the u-tube method.  Once you've done it a couple of times, then you get an idea for how hard to push on the tab to make, say, a 2mm change in float height (hint: not very hard).  But the thing is: you can't really visually see much change at all in the tab istelf.  You push lightly on the tab, and the float height changes, but the tab doesn't appear to change hardly at all.  I think if you moved the tab 2 or 3mm, then that would seem to be way too much to me.

I'm starting to think that reason it was out of adjustment was because the float needle+seat (aka the little plunger and seat) is worn out and is sitting farther down.

The float needle should have a little bit of "spring" to the tip... you can just barely feel it with your fingers.  It feels a little bit like the spring-loaded tip of a Palm Pilot stylus, if you've ever seen one of those.  If the tip has no spring left, then it may make the float level end (say) 0.5mm too high (not much), and also probably fuel into the bowl. Try tapping on the ends of the two float needles with your fingers, and see if they feel different from one another.  The Partsnmore.com rebuilid kit ($12) includes two new needles, so there's an easy fix for that.

My specific problem comes from DJ saying i should increase the float level 1-2mms to make the carbs run leaner in WOT operation

Well, you'd increase the float height measurement (per the Haynes method) by 1-2mm, and this would LOWER the float level by 1-2mm, making it run leaner; that's probably what they meant.  

But it strikes me that float height is not where you want to make adjustment to change WOT mixture.  That's like saying that you should run 14-inch wheels to get better power ... it just doesn't seem like the right way to change the mixture, because (A) it's effect is not consistent for a given throttle opening (sustained WOT should be affected more than brief WOT), (B) it could cause power loss in hard cornering, and (C) there are better places to tune the mixture.

I read Octane's recent posting, saying that the supplied Dynojet stage 3 jet (134)  is just too large for him, even though he has a full V&H pipe and a K&N unipod.  Now, Dynojet should know what they're talking about.  But it's impossible to have just one or two main jet "stages" suitable for all possible exhaust/intake combinations, and maybe what you need is a "stage 2.7" jet kit!  You may need a slightly smaller main jet.  Note that Octane said he's lean under 4500rpm, so you may want to try a little richer on the needle.

Where do i get on of those tube dealios?

I just use about 6 inches of small tubing from the hardware store (not sure what size... very small).

[mercdude63]

Ok this is the kind of feedback I need.

We are talking about the same tab... there's only one tab to be bent on the float bowls. Which direction do you bend the tab to lower the fuel/float level. I am trying to picture what i did, because i'm not sure if i did it right. I bent the tabs towards the needle plunger--i THOUGHT that would decrease the float level and make the bike more lean. Now that i'm thinking about it, i think i bent the tabs maybe 1-1.5mms, but it only increased the measurement by 2-3mms. maybe i was measuring it wrong. Or... did i make the float level higher? I'm getting confused because it was upside down.

I need to make the bike run more lean overall, i think then it will run fine with the needle clip position set on lean as well. Honestly, i think the other guy didn't adjust the float level and decided instead to just swap out the main jet. They (DJ) did say that for this bike+jet setting that if you have problems below 4k that you need to adjust the float levels... i mean, i called them on being "generic" with their packaging and they were very firm that their package was designed, researched specifically with this bike in mind. So  :dunno:  I'm never buying their shaZam! again though.

[goat]

I've been wrestling with my carbs for about a month now after I rejetted.  In retrospect, I should have thought harder about paying someone to do this.

I have been following this guide and right now, I have my floats set about 2mm above (so they are low) what suzuki reccomends. When I set my floats at 14.6mm, it would stall at stop lights because it was running so rich. I'm still having problems getting my bike to run right in the low end, but it's better than it was. Now that I am done with school for the summer, I hope to have some more time to fix this soon but that has nothing to do with your post

Anyhow, I wish you the best of luck and from what little I have done; I wouldn't treat suzuki's specs as gospel after a rejet. Make the bike run well and the only way to do that (in my opinion) is to ride it.

[Rema1000]

Goat, that's a good link!  I had not read about using the float height for anything other than "special circumstances" (racing, alcohol, etc.)

But I've always wondered how you can set the main jet, then needle, then finally pilot, when changing the pilot changes fuel at all throttle positions.  It seems like you should work from main->needle->(bowl height?)->pilots; but any time you change the float height or needle position or pilot size, go for another round of tests, starting back with full throttle, high RPM again.  If you only had to change the pilot adjustment screws, then you may want to check mid-range, but retesting WOT is probably not necessary.

[mercdude63]

Yeah, i'm having one hell of a time getting this thing right... maybe i should have payed someone to do it too. Oh well, i'm out of school/graduated so i just come home from work and mess with the bike a couple hours every day. Then i just give up and call it a night... every night for the last 3 weeks!!

I put my floats at 17mm and it's starting to run lean at steady cruising, but still has the stumbling problem at low rpm. My father says that's the main jet+needle, DJ says that's the idle, slide, and float level. and i'm like "F***!" I have a tendency to think that's the main jet size in combo with the slide opening too fast.

this is really frustrating.

jon

[mercdude63]

ok after getting a few different opinions from DJ, the last person i talked to said to adjust the main jets down a size to the indicated 128s (that's the smaller stage III jetting... the other sizes are too small as they are for stage I). Since i'm getting bogging under WOT, that is a main jet, needle problem. So they said to put back the float level to richen it up (joy) and then put the smaller mains in (no prob) and then try that. Most likely it'll clear it up to where the bike will have to be richened up. But i don't really know... seems nothing works quite right. Oh well. I'll keep everyone/no one posted  

jon

[Alias]

I've been wrestling with my carbs for about a month now after I rejetted.  In retrospect, I should have thought harder about paying someone to do this.

I have been following this guide and right now, I have my floats set about 2mm above (so they are low) what suzuki reccomends. When I set my floats at 14.6mm, it would stall at stop lights because it was running so rich. I'm still having problems getting my bike to run right in the low end, but it's better than it was. Now that I am done with school for the summer, I hope to have some more time to fix this soon but that has nothing to do with your post

Anyhow, I wish you the best of luck and from what little I have done; I wouldn't treat suzuki's specs as gospel after a rejet. Make the bike run well and the only way to do that (in my opinion) is to ride it.

I should have payed someone too. I am only bogging under 5K at WOT, top end is perfect.

[The Buddha]

OK lovely...
BTW, FWIW, IMHO, POS DJ is crap.... but Caddmonkey's carbs on my bike ran good with 134 mains when the bloody floats weren't stuck open or closed...
The slides had one hole consitricted with the usual DJ plug and I drilled down the middle of the other to make it just like the one with hole... used a #46 drill If I remember. Wont recomend others do this... but seemed to help caddmonkeys carbs... I'll let him post the final word on that.
Cool.
Srinath.

[mercdude63]

My problem happens at WOT and only if I crack the throttle open as fast as I can RIGHT off idle. The slides, at this point, are already all the way up. if i feather the throttle at all... go slower, etc... runs awesome. Hey, if it worked for you and that guy's carbs, SUPER. But that's not working with mine. Of course there's the obvious "i want it just the way it was before but way better" situation which, apparently, stage III jetting isn't really designed to do. It's possible, god i hope not, that this is the best it gets. or, maybe my head needs a valve job at 32k, probably does, but i can't think that'd have that much to do with how it ran. I looked at the valves and the cam lobes barely have any wear on them. Looks like about 60k on a car engine.

my plan of attack: smaller jets, raise fuel level, stick with needle clip position at highest, 2 turns out on fuel mixture. I'll let everyone know how it runs... of course.

jon

[Rema1000]

My problem happens at WOT and only if I crack the throttle open as fast as I can RIGHT off idle.

Well, most carb tuning is done with static throttle: does it work at sustained WOT? 3/4 throttle? 1/2, 1/4, idle? then you're good!  .  Then there's a separate area of tuning carb slide responsiveness.  That helps to determine how fast you can jump to WOT... but from idle?!  I can't do that either with my homebrew jetting .  Did that ever work for you (with stock jetting)?

Generally, the people who care most about jetting are the racers, and they spend all their time in the powerband; so they probably couldn't care less how fast the bike responds to WOT off idle.  So it sounds like you're asking for a type of performance which is outside what many people care about... and the conventional advice may not get you where you want to go.  For things like idle->WOT transitions, I suspect that fuel injection is the easy solution.

maybe my head needs a valve job at 32k, probably does, but i can't think that'd have that much to do with how it ran. I looked at the valves and the cam lobes barely have any wear on them. Looks like about 60k on a car engine.

Car engine has self-adjusting valve lifters.  GS uses shims.  As the valve seats wear, there are no adjusters, so the distance between the valves and cams just gets tighter and tighter, until the cams score.  You need to check cam clearance every 6k miles (although it may only need a new shim every 20k).

[mercdude63]

Seemed to me that it USED to run fine doing that. Of course, I might just be wasting my time. I had it set pretty good but this stumbling thing had me worried... so i figured i could get it better. I put in the smaller stage III mains and reset my float level at 14.5... we'll see how that works. My suspicion is that it will hurt top end a little, but give me better low end. I also suspect that when the slides go all the way up and let all the fuel from the mains out... that its too much for the rpm range of the engine... but as the need for more air comes in and rpms go up... then the fuel is used. This is also suspect because i have to run the needle clips at the highest level. So to sacrafice a litle top end, i'll go with the smaller mains and adjust using the needle. However, the ones you used are supposed to small for setup that i/we have. They are the larger stage I jets... i'm using the smaller stage III jets. eh, they aren't that far apart i guess.

i checked my valve clearances, they're within spec. Apparently no one has ever changed the shims in the 32k, but the were still in spec. Crazy.

jon