Fuel level adjustment

This doesn't make any sense to me!

Suspecting my fuel levels were way high I decided to do a fuel wet level check. The levels were high....instead of 3mm below the carb body seam they came right to seam. I pulled the carbs, took the float bowls off and checked the height measurement according to the service manual which called for a 17.5mm height from the mating seam (minus gasket) to the top of the rounded part of the float. The measurement I got was 19.5 - 20mm! If I adjust them to the 17.5mm figure won't the fuel level be even higher than it is now?

If you raise the float you raise the fuel level....no? :?:

 

That's the problem with "dry setting." The measurement is only a starting point; think about how small that 2MM difference really is.

And how important it is.

The amount of tweaking on the tangs will be minimal to the point of not being sure you did anything. Bend it enough to know you bent it and you'll go too far.

 

I'll do a wet level in the morning but thinking I won't even bother with the dry set on the other three carbs, there's too many variables....just do old school trial & error wet levels.

 

OMG another person with person that's a 5th gear that having problems with the carbs. Yesterday it was someone that rebuilt some carbs but they were leaking. I read yet another post that one of those vacuum plugs was blown off. Did these bikes ever run brand new? I read the factory TSB. These bikes must have been a pain to set up brand new. You can't even follow the factory service manual that it will lead you astray.

 

Yeah I never bothered trying to dry-set the floats. It is a pain in the butt no matter how you do this (wet or dry) so doing it wet seemed to give more 'realistic' results in my opinion. Get yourself confident in where the levels are suppose to be and keep fiddling around with the tangs and re-filling the float bowls until you get them accurate, and you'll be riding plenty of miles in the future with happiness. Trust me its how to get excellent gas mileage and a grin every time you blip the throttle under acceleration no matter how fast you were going before.

 

Go astray somewhere else besides this website, altlandf. Nobody cares what you have to say anymore; you've created a bad image of yourself already. Laugh all you want, but more than just one person on here has gotten success in resurrecting an OLD motorcycle and we take pride in helping others on here. If you don't have anything nice to say, don't say anything at all.

 

Well, now that you know the fuel level is high, you can deal with it.

Remember, we're not raising the float itself -- we're bending the tang arm that the needle sits on. To lower that dry setting, one would have to bend that tang arm away from the carb body; this would cause the fuel level to rise.

So, the answer would be yes, it would.

Fitz is correct in that the dry set is a starting point. It gets you close; then wet set one of them, get it to where the fuel level is correct, then dry set the other three to match. They should fall into place.

Do you have a float gauge? Something with which to measure them dry? I show two of them in the writeup; Chacal should have them on hand. Comes in very handy.

 

[/quote]Fitz is correct in that the dry set is a starting point. It gets you close; then wet set one of them, get it to where the fuel level is correct, then dry set the other three to match. They should fall into place.

Do you have a float gauge? Something with which to measure them dry? I show two of them in the writeup; Chacal should have them on hand. Comes in very handy.[/quote]

This is what I planned to do, set one the hard way and go from there. Just puzzling that the service manual dry setting isn't even close...not going to even bother doing a wet level at their setting, just a waste of time.

No, I don't have a 'real' gauge...I have a small shop rebuilding VMax & Venture carbs and make my own gauges from the plastic tops off vitamin bottles....always thought about getting the proper tool but..."if it ain't broke...." lol

To the previous poster about whether these bikes ever ran well or not....I bought this bike new in '85 and you want to believe it ran well....and still runs well!

Just dealing with a little maintenance issue, that's all.

 

I'll take a stab at breaking it down mathematically.

I've only wet set my carbs once and the numbers I'm using are guessed from looking at a few pics of floats but the logic stands.

Set the floats on a table and look down at them. Let's say that the that the point the tang contacts the float needle is 5mm from the pivot point and the center of the floats is 20mm from said pivot point. As everything here is proportionally relative and the the distance from pivot to tang is 1/4 the distance from pivot to center of floats, to raise or lower fuel level 1 mm where the center of the floats is at fuel level, then the tang needs to be bent up or down a quarter of that or .25 mm.

So in the words of Fitz, if it looks like you bent it you bent it too much.

 

The fact of the matter is, ... they WERE a pain in the ass when new.
With a two and a half out Pilot Screw Factory pre-set and a herky-jerky Exhaust Gas Analysis, ... most of them stalled at lights and trips to the Dealer for adjustments had Service Managers pulling their hair out.

Most places just gave the Air Screws a twist out to two and three-quarters hoping that it would stem the flow of unhappy customers.

Eventually, ... when Colortuning replaced guesswork ... owners found-out that they could FIND a starting-point that brought a smile to their faces.

ColorTune "Blue"
Blue sets your IDLE.
ColorTune the rack to Blue and the Bike will Idle on its own until it runs out of gas.
But, dialing-in Blue is just the beginning.
The plant needs a little more richness added to that Blue to avoid coughing and sneezing trying to get out-of-the-hole.

Latter day XJ-guys discovered our Forum and the new era of Tweakers began with throwing-out the Factory pre-sets, plug-chopping, experimentation, ColorTuning, and learning the value of Valve adjustments, clean-as-a-whistle carbs, and the elements of Strong Ignition circuits and Synchronized Carbs paramount for achieving Hitachi-CV-Carbs high-performance Zen.

 

I got them in spec using wet level checks only....there are just too many little variables for 'one measurement fits all' to be successful. There were small differences in elevation from one side of the float to the other (slightly twisted probly), there is a small amount of play between the float and mounting pivot pin, etc.

So I set them all the same per the calipers and then removed the variances with wet levels. It's kind of a PITA but you get pretty good at it after a couple dozen trys. :lol:


Rick, there weren't a lot of these X's around when I bought mine and obviously no computers to dial up the XJ Bikes Forum on, so I had no info other than my bike but she always ran beautifully, none of the symptoms you described. I put 8,000 mi. on without a hic-cup before selling it (foolishly) And now that I have it back it still runs great....a little 'soggy' down low but I'm thinking the float adjust will cure that.

 

First time I did float levels on the X, I used a toothpick for dry-setting. (I demonstrated this in the Mikuni cleaning writeup I did... I really should update that one of these days.)

The purpose-built tool works SO much better.

 

Double checked the wet levels, all four right on 3mm so I reinstalled the carbs and fired it up. Started at the touch of the button, sat idling smoothly, took gas well and returned to idle as it should. As it got warmer it would return to idle slower.....the warmer it got the slower it returned. Revving when fully warmed up it will quickly return to 2000 - 2500, hang there for several seconds then return to 1k idle.

After letting it go thru a couple fan cycles, it will idle smoothly then creep up from 1k to 1200 or so, then in a few seconds climb up to 2k, stay there for 15 - 20 seconds then drop back to 1k, stay there for maybe a minute then repeat.

The hanging idle has been an ongoing problem which I had hoped was a result of high fuel levels but apparently that is not the case.

Carbs were rebuilt last year, less than 100 miles ago, same for valves all in spec less than 100 miles ago, throttle snaps back 'with authority', no pre-load on the starting enricheners, no vacuum leak signature and seems unlikely as this problem has remained thru 3 or 4 carb removal/installs with no noticeable change, new fuel filter.

I'm thinking this has to be fuel related....anybody run across something similar?

 

You are describing the classic symptoms of an out of sync condition. Not wildly out; you're very close. But it's out of sync.

 

exactly what I was thinking.

CN

 

This is good news....thanks!

Sync is the final step but I ran out of time last night figuring I could get to it...'later'. :roll:

It did occur to me that could be the problem but the symptoms had nothing in common with an out of sync VMax so I charged right ahead and began to over analyze....hate it when I do that.

It's snowing like a big dog here right now but doesn't look to be a long duartion thing....time to throw the duds on and go do some sync'n!!

 

In order to get a real solid sync, the bike needs to be fully, as in 20-mile ride, warmed up.

It might have to wait until the new riding season is upon us. I need to do a "touch up" sync myself (after a valve adjustment) but it's just gonna wait.

 

I gotta be perfectly honest with ya, when I saw the Carbtune rods a smidgin of doubt crept in....they were off but not very darn much! Apparently these things have a zero tolerance sync policy....they're either right or they're wrong, there's just no wiggle room!

So after a minor bit of tweakage.....no more 'hunting idle', rpm's drop right down like they should, all seems nice & normal.

BUT, another issue appeared! After the fan cycled a few times it began to run rough and snapping sounds appeared....knew right away what that was and sure enough, bunch of arcing going on all around the #2 & #3 TD-140's....possibly #1 & #4 also but I didn't notice any at the time.

I'm running Dyna coils, 8mm plug wires, the TD-140's have been disassembled & cleaned, all contact points polished, oem resistors removed/swapped for 5mm (I think) brass slugs.

Could the arcing have something to do with those modifications?

Thanks for the info, you guys were right on the money, as always! Here's a pic of the final sync....or final for now until I can get back in and do it right.

 

I love my CarbTune too. And I really love it when it looks like that. And yep, sync is sync and it doesn't have to be off by much to get all bitchy.

Can't help you on the ignition issue; but it sure sounds like you've got a handle on where to look anyway.

 

Yeah it really came out better than I expected for the conditions I was working in.

Funny but I could hear and feel it when she hit the sweet spot....the engine note changed, just sounded happier....maybe a little more aggressive too!!

Thanks again

 

Well, I bit the bullet and got four new TD-140's, switched the resistors out for some brass slugs I made to match the DynaTek coils and wired them up.

Even tho the voltage was indicating a painfully low battery I decided to try it anyway....I hit the starter button and the damn thing never even turned over....seriously, I never heard it turn over, it was just running. Tried it again and as soon as the starter button is pressed the motor is running! Never saw anything start like this bike....wish I could get a VMax to start this well!

I dobbed some di-electric grease around the base of the orange boot....to help it slide in the deep plug well as much as anything, I guess....and will fire it up to let it go thru a few fan cycles today, see if the arcing is fixed

 

My '83 550 starts like that. It never even gets a "half a crank" before it lights off.

 

When you are dialed-in, ... you can do a "Phantom Kick-start"

Hold the Start Button in.
Pull the Clutch Lever.
Tip the Bike off the Side Stand.
Flick the Side Stand up, ...
Zaroom ...

 

That's funny! I'm thinking of showing the bike at the local car/bike show this summer and may give that a try....being big Harley country around here I might be able to get away with it, they won't even know the difference! :lol:

And probly won't care either! 8O

Oh, I let the bike run thru 4 or 5 fan cycles today and no spark jump so that's good. Need some highway time to really tell tho....just got to wait for the glacier to receed.

 

Dude quit gloating. I try not to "rub it in" that mine fires with a 1/2 rev of the motor (and has since I put it back on the road.)

The Morgan is the secret; gotta be. I love getting them not close but spot on. That and microscopically accurate float levels (and Mikuni carbs, but shhh...)

 

A great tool, the Morgan but ya gotta keep them clean. Kind of surprising how quickly they get dirty but certainly easy enough to take apart and rub down with a little denatured alkie.