Help!!!

[countrycummins99]

ok took the advice of everyone here i dipped the carbs 8 hours a piece and used four cans of carb clean on them also they are officially the cleanest carb i have ever owned. Next i installed the stage 3 jet kit from dynojet it included new needles with the adjustable eclips i set them to the second position down as recommended. Then i set the mixture screws to one full revolution out from closed. now the bike runs like S&%T so any help would be appreciated starting to get discouraged. Also the main jets are dynojet 118 and the pilot jets are mikuni 40 bike is acting like its not getting enough fuel i set the float height to the recommended 20.5 mm. fuel flow to the carbs is excelent so thats not the issue only thing i can think of is that i have the needles set to far closed and the mixture screws not out far enough. please help

[Steve]

OK, the first bit of help is going to have to come from YOU.


WHAT BIKE ARE YOU TALKING ABOUT???


It's not mentioned in your plea for help, it's not in your signature, I am just too darn lazy to look up any previous posts to see what you might have.

What difference does it make? PLENTY. On some bikes that "one turn out" might be too much, on others, it's WAY too little.

By the way, it's also possible that your carbs are still not clean, and you used WAY too much spray.
Most of the time, carbs should be dipped for about 24 hours, especially if they are of unknown quality.
I typically clean three or four SETS of carbs (yeah, 12 to 16 carbs) on just ONE can of spray.

.

[posplayr]

Yea what bike, what mods? 4:1 pods? ......... ?

[rapidray]

To start with, the mixture screws need to be 2.5 turns out to begin adjusting things. Then set the mixture screws CORRECTLY by using the "fastest idle method. Ray.

[BassCliff]

Hi,

Forgive me for asking the obvious.

Did you completely disassemble the carbs and remove all the old rubber O-rings? Did you reassemble them with a new set of O-rings from http://cycleorings.com? Did you use any aftermarket "carb kits"? Did you bench sync the carbs before putting them back on your bike? What kind of air filter do you have? Are these VM or CV carbs? VM carbs have a fuel screw and an air screw. CV carbs have a single pilot screw for the idle circuit. It helps to know the year and model of your bike.

Did you use these as a reference?

Mikuni BS(CV) Carburetor Rebuild Tutorial
(Mr. Nessism)

CV Carburetor Rebuild Guide
(Courtesy of GSR and John Bloemer)
(Click here to see the CV Carb Notes)


Thank you for your indulgence,

BassCliff

[countrycummins99]

Make model

Ok the model of the 1983 gs550es which means it has the twin Siamese carbs the carbs are completely spotless inside and out no way possible their dirty. Next the carb were pulled completely apart o rings were not replaced because I found none that were bad or cracked or dried out the carbs are synced but their not vacuum synced yet

[countrycummins99]

What about needle height to? Also it's got a stage three kit from dynojet didn't use a rebuild kit and it has a k and n factory replacement filter

[BassCliff]

Hi,

You should probably start with the clip on the needles in the second slot from the pointy end. The pilot screw should start about three turns out and adjust from there. Make sure there are no air leaks in the intake boots or intake boot O-rings. Make sure the float height is correctly set. Are you sure the petcock is working properly?

Sorry to be so general in my recommendations but I'm not that familiar with the siamese carbs. Keep us informed.


Thank you for your indulgence,

BassCliff

[Agemax]

why dont you put in your signature what bike you have and what mods you have done to it. we are getting fed up with asking or guessing!!!!!!

do you have a stock exhaust? if so a stage 3 dynojet kit may be too much if you just have a stock replacement filter. stage 3 is designed for pods and an aftermarket performance pipe

[elrico]

Did you examine the entire air intake/induction system.. all components before carbs inlets and after carbs outlets for air leaks? The one many leak most overlooked is the 4 large O rings sealing between the intake stubs and the cylinder head and will cause major starting and running problems.So whatever problems you do/may otherwise have please do yourself and your GS a big favor when those carbs are removed again.Replace these intake stub O rings.You will have to sooner or later and you will know you have eliminated a possible or exact problem causing area.You have multiple problems,eliminate them one by one.No grand slam home run cure,start by just getting on base and progress as you will.I have an 83 GS 550 ES for 18 yrs,now,am no expert but my Suzi has been a good instructor for me,be patient you will prevail.

[countrycummins99]

update

moved the needle to 2 from the bottom and moved the mixture screws out to 2.5 turns now the bike is so rich that if you touch the throttle while it is idling it instantly kills the bike so i am guessing i have the needles open to far now what do you all think? other think is it appears the vacum gauge bounces does that point to yet another problem?

[Steve]

Ok the model of the 1983 gs550es which means it has the twin Siamese carbs the carbs are completely spotless inside and out no way possible their dirty.

The dirt that you can see is NOT the dirt that matters.

What matters are all the little passages that are deep inside the carb bodies. It is quite possible that one small speck of crud has somehow found its way in there, and is stuck against a jet. Removing the jet will find a very clean jet, but the crud remains.

Next the carb were pulled completely apart o rings were not replaced because I found none that were bad or cracked or dried out ...

Do you know when (if?) the o-rings had last been changed? An o-ring that looks perfectly fine might have shrunk down to the point where it is not quite sealing properly. Unless you remove them and measure them, you simply won't know for sure. Cracking and drying out are not the only way they fail. And, ... if you took the carbs all the way down to the point where you could see the o-rings, why not change them (unless you know that they were changed recently)?
To add one last note to this, you must have removed the o-rings to dip the carbs and parts. You telling us that you put the old o-rings back on? Or are you saying that you did not remove them when you dipped them? Sorry, but either situation is a HUGE red flag.

... the carbs are synced but their not vacuum synced yet

That should at least get the bike running.


Looking back at your first post, along with subsequent replies, it appears that you have a wild mix of jetting going on. It appears that your bike is an '83 550.
- Stock pilot jet is 35, you now have a 40. There should be no need to change from a stock pilot jet.
- The main jets are DJ118, which is the same as a Mikuni 110. That is three sizes up for your center cylinders and six sizes for your outer ones. For just adding a header, that should be plenty, maybe a size too rich, but that won't affect your idling performance.
- Your needle clips are in the second groove. Your bike might be different (I have never installed a DJ kit on a 550), all the DJ instructions I have seen say to have the clip in the third groove.
- Your mixture screws are one turn out. That is even leaner than stock, but with your oversize pilot jet, it might be correct. Even though it might compensate while at idle, there are other ports that open up just as soon as you start to open the throttle (I call them "transition" ports). With your oversize pilot jet, they will greatly richen the mixture just as soon as you move the trottle above idle.

Your idle jetting might be perfect. (oversize pilot jet, compensated by small mixture screw opening)
Your transition jetting might be rich. (oversize pilot jet)
Your needle jetting might be lean. (needles set too low)
Your main jetting might be rich. (main jets too large)

Rather than starting with an imbalance and trying to compensate, try setting things back to stock, except for the things you KNOW you need to have different. Go back to the stock 35 pilot jets. Double-check the needle clip setting. Turn the mixture screws out three turns. Double-check your float height (make sure you are measuring at the correct part of the float).

After all of this, it should run. Let it warm up a bit, do a vacuum sync to make sure that is not causing any problems, run the bike a bit more to fully warm it up, then do some "plug chops" to read the color of the plugs. No, you don't have to get out the Dremel and chop up your plugs, you merely hold the throttle at specific openings to check the different circuits in the carbs, run the bike long enough at that opening to color the plugs, then "chop" the throttle, pull the clutch lever, hit the "kill" switch and coast to a safe place where you can remove the plugs to inspect them.

.

[countrycummins99]

thanks for all the info the size 40 jets for the pilot are the only ones i have they were already in the carb dont have stock 35 so i dont have a choice there. the only orings in these carbs are one ones on the transfer tube the float valve and the tiny ones on the outer pilot jets i didn't replace them because i simply didn't have them at the time. the dj kit says to set the mixture screw to one turn out and the eclips on the needle one grove down from the top currently the bike starts and idles great i also did the vacuum sink on the carbs. bike will respond to throttle but falls on its face around 5000rpm i have bout had it i have tried just about everything i know on this and to no avail its worse then i started with

The dirt that you can see is NOT the dirt that matters.

What matters are all the little passages that are deep inside the carb bodies. It is quite possible that one small speck of crud has somehow found its way in there, and is stuck against a jet. Removing the jet will find a very clean jet, but the crud remains.



Do you know when (if?) the o-rings had last been changed? An o-ring that looks perfectly fine might have shrunk down to the point where it is not quite sealing properly. Unless you remove them and measure them, you simply won't know for sure. Cracking and drying out are not the only way they fail. And, ... if you took the carbs all the way down to the point where you could see the o-rings, why not change them (unless you know that they were changed recently)?
To add one last note to this, you must have removed the o-rings to dip the carbs and parts. You telling us that you put the old o-rings back on? Or are you saying that you did not remove them when you dipped them? Sorry, but either situation is a HUGE red flag.



That should at least get the bike running.


Looking back at your first post, along with subsequent replies, it appears that you have a wild mix of jetting going on. It appears that your bike is an '83 550.
- Stock pilot jet is 35, you now have a 40. There should be no need to change from a stock pilot jet.
- The main jets are DJ118, which is the same as a Mikuni 110. That is three sizes up for your center cylinders and six sizes for your outer ones. For just adding a header, that should be plenty, maybe a size too rich, but that won't affect your idling performance.
- Your needle clips are in the second groove. Your bike might be different (I have never installed a DJ kit on a 550), all the DJ instructions I have seen say to have the clip in the third groove.
- Your mixture screws are one turn out. That is even leaner than stock, but with your oversize pilot jet, it might be correct. Even though it might compensate while at idle, there are other ports that open up just as soon as you start to open the throttle (I call them "transition" ports). With your oversize pilot jet, they will greatly richen the mixture just as soon as you move the trottle above idle.

Your idle jetting might be perfect. (oversize pilot jet, compensated by small mixture screw opening)
Your transition jetting might be rich. (oversize pilot jet)
Your needle jetting might be lean. (needles set too low)
Your main jetting might be rich. (main jets too large)

Rather than starting with an imbalance and trying to compensate, try setting things back to stock, except for the things you KNOW you need to have different. Go back to the stock 35 pilot jets. Double-check the needle clip setting. Turn the mixture screws out three turns. Double-check your float height (make sure you are measuring at the correct part of the float).

After all of this, it should run. Let it warm up a bit, do a vacuum sync to make sure that is not causing any problems, run the bike a bit more to fully warm it up, then do some "plug chops" to read the color of the plugs. No, you don't have to get out the Dremel and chop up your plugs, you merely hold the throttle at specific openings to check the different circuits in the carbs, run the bike long enough at that opening to color the plugs, then "chop" the throttle, pull the clutch lever, hit the "kill" switch and coast to a safe place where you can remove the plugs to inspect them.

.

[elrico]

Check intake and exhaust valves for proper specs.and adjust if/as necessary before attaching carb set.Whenever it becomes time for carb installation,you will know the valves are in spec.and tuning carb set will be less problematic and accurate to begin with.

[BassCliff]

Hi,

Forgive me, I'm still trying to get a complete picture.

Why did you install a DJ kit? Do you have a non-stock exhaust or a non-stock air filter?

You can always buy the stock pilot jets if you need to. Those don't often need to be changed even after modifying the intake and exhaust. Of course, it depends on the modifications.

Thank you for your indulgence,

BassCliff