gs550l choke

[Guest]

hi all so after my dad pulled the carbs off again to check specifically ino 4 he cant see nothing wrong pulled out all the jets etc cleaned again .ive had a look and just wondering how the choke works beacuse one thing that was happening was when started no throttle no choke bike idled ok but if i put choke on revs increased but when shut choke off revs hanged then if i turned engine off and restarted revs were normal again.i see the little hole the choke uncovers under the diaphram when choke is on does it pull air through this hole which increases pressure under the diaphram lifting slide up for choke! cheers paul

 

[tom203]

You can’t just look at these carbs and decide “they’re clean”. There are tiny passages in carb body that feed/control the idle and low speed circuits . Once clogged, bike will start but will behave badly.


the little hole under diaphragm feeds air to choke plunger..making a mixture ....it doesn’t do any lifting cuz at startup and low speed diaphragm isn’t functioning. However if “choke” is left on ,this excess mixture will cause high idle

 

[Burque73]

hi all so after my dad pulled the carbs off again to check specifically ino 4 he cant see nothing wrong pulled out all the jets etc cleaned again .ive had a look and just wondering how the choke works beacuse one thing that was happening was when started no throttle no choke bike idled ok but if i put choke on revs increased but when shut choke off revs hanged then if i turned engine off and restarted revs were normal again.i see the little hole the choke uncovers under the diaphram when choke is on does it pull air through this hole which increases pressure under the diaphram lifting slide up for choke! cheers paul

Here's an animation showing what happens when the choke is opened.

 

[pdqford]

Many thanks for that animation.
Amazing how much is going on with all the overlapping circuits.

 

[Big T]

While the carbs are off, now's the time to give the carbs a proper cleaning and new O rings

 

[Steve]

Just two suggestions here.

1. What year is your bike? Over the years, there were THREE different types of carbs on a 550L, it would be nice to know which ones are being discussed.

2. Punctuation, spelling and grammar are your friends. Your post is a bit hard to read, but I got most of it.

.

 

[Big T]

Yeah, at least hit the space bar at he end of each sentence

Then, go to your settings, signature and put 1982 GS 550L there

You need http://zeus.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

http://zeus.mtsac.edu/~cliff/storage/gs/Mikuni_BS-CV_Carburetor_Rebuild_Tutorial.pdf

and, while your Dad may resent it, read this 1st https://www.thegsresources.com/_for...Newbie-Mistakes&highlight=top newbie mistakes
It's the hundreds of years of our accumulated knowledge, created by doing things the wrong way, then figuring out the right way

PS, CycleOrings.com ships worldwide

 

[Nessism]

Newbie Mistakes thread and carb rebuild tutorial linked in my signature. Both should help you.

 

[Guest]

You can?t just look at these carbs and decide ?they?re clean?. There are tiny passages in carb body that feed/control the idle and low speed circuits . Once clogged, bike will start but will behave badly.
View attachment 62269

the little hole under diaphragm feeds air to choke plunger..making a mixture ....it doesn?t do any lifting cuz at startup and low speed diaphragm isn?t functioning. However if ?choke? is left on ,this excess mixture will cause high idle

hi thanks for all the replies can you get to clean these little passages, the carbs have been cleaned in the bath twice at a shop,i havent had chance yet to look at all the tutorials but i will .the carbs havent just been looked at everything that we could take out or apart has been and cleaned, i will order some orings too.so when the choke is open how is it richening the mixture! thanks for all your help paul

 

[Guest]

hi roger nice video thanks for your help but not how my choke works mine is a 1982gs550l and when choke is pulled a slide opens up a hole under the diaphram trying to work out how this richens the mixture! regards paul.

 

[Steve]

That video is not perfectly correct, but it's close enough to give the idea.

First of all, "choke" is a term that does not technically apply here. What we have on our carbs is an "enrichment system". The system does the same thing, but it does it by opening specific ports to supply a richer mixture not by closing off the inlet of the carb to choke it.

If you actually had the carbs all the way apart, you would have seen the brass plunger that would slide horizontally to uncover that hole under the diaphragm. When holding the plunger, you should have seen the pin on the end. When the plunger is pulled to richen the mixture, the larger barrel part uncovers the air port, that pin moves away from a fuel port that goes down into the float bowl.

One other thing to note is STARTING TECHNIQUE. Because of the way the enrichment system works, it relies on the high vacuum of a CLOSED throttle. When trying to start the cold engine, you turn the key ON, move your "choke" lever to somewhere between 1/2 and full ON, pull the clutch lever and push the starter button. Do NOT touch the throttle. If you move the throttle AT ALL, the open throttle butterflies will destroy the high vacuum that is needed to pull the gas through the enrichment circuit. Once the engine is running, adjust fast idle speed with the "choke" lever, NOT the throttle.

You say the carbs have been "cleaned in the bath twice at the shop".
What liquid was in the bath? How long were the carbs in the bath?

.

 

[Guest]

choke gs550l 1982

choke gs550l 1982

That video is not perfectly correct, but it's close enough to give the idea.

First of all, "choke" is a term that does not technically apply here. What we have on our carbs is an "enrichment system". The system does the same thing, but it does it by opening specific ports to supply a richer mixture not by closing off the inlet of the carb to choke it.

If you actually had the carbs all the way apart, you would have seen the brass plunger that would slide horizontally to uncover that hole under the diaphragm. When holding the plunger, you should have seen the pin on the end. When the plunger is pulled to richen the mixture, the larger barrel part uncovers the air port, that pin moves away from a fuel port that goes down into the float bowl.

One other thing to note is STARTING TECHNIQUE. Because of the way the enrichment system works, it relies on the high vacuum of a CLOSED throttle. When trying to start the cold engine, you turn the key ON, move your "choke" lever to somewhere between 1/2 and full ON, pull the clutch lever and push the starter button. Do NOT touch the throttle. If you move the throttle AT ALL, the open throttle butterflies will destroy the high vacuum that is needed to pull the gas through the enrichment circuit. Once the engine is running, adjust fast idle speed with the "choke" lever, NOT the throttle.

You say the carbs have been "cleaned in the bath twice at the shop".
What liquid was in the bath? How long were the carbs in the bath?

.

hi steve great i see now i will check out how they were cleaned,its been abit awkward for me as its my dad that has done work and i recently got involved to help him out as he is 80yrs old he doesnt have a laptop to get this valuable info and he is getting abit downbeat im more of a 2 stroke guy as i race 2 strokes,so i havent come across carbs like these before and certainly not 4 in one go, now i understand how and where the mixture is getting enrichend i will check these passageways out for the fuel, i could see what the brass slide was doing with the air but didnt realize it was also letting fuel in too thanks for all help regards paul

 

[cowboyup3371]

Just note you won’t be able to see them very well. What everyone is really trying to say is do the work yourself using the procedures Nessism wrote and you’ll be better off. You can also send them to someone here on the forum to do for you