My first GS, its got issues :p

[BushcrafterQC]

Thanks for this forum, I just bought my first road bike, a 1982 GS550L. My last favorite bike was a DR650, oh boy is this a smooth change. 

I got a good deal for it (i think :p) because it has carb issues. The P.O. is an auto body guy and it was his first bike, he restored it, it wasn't running for 20 years. But since he put pods on and got his friend to mess with the jetting, its not running good. The P.O. isn't much of a mechanic and was tired of trying to get the carbs tuned. I am an automechanic so i figured i'd give it a shot. the only carb experience i have is on some tractors and a dual Dellorto carbed Rx7. 

The previous owners friend cleaned the carbs and precision drilled the jets to make it run rich, because of the pods. Luckily, he still had the stock air-box. 

I'm thinking of finding the stock Jets for it and putting the stock air-box back on. Does anyone know what the stock jet size are? What would you start doing to it first?

The bike starts up on a 1/4 turn so i know the compression is good. But it starts cold without the choke and did a few back fires once. Looks to me like its running too rich. trying to figure out how to adjust the settings for the idle as it runs high and on startup gets carried away to 3000 rpms... sometimes... haha 

I can still ride it but it doesn't have much power past 5k and over 70kph feels real slow.

The clutch is real heavy and the cable looks old so i will try and change that. 

Any input is good! thanks! 

I will be getting some tools to sync the carbs and maybe one of those color tuning plugs to help.

[Joseph]

Well in theory, putting back the stock jets and airbox will make the bike run good

But

Thats what i did on my GSXR 750 W,

The bike was running great, but i wanted to lower the intake noise and see if i could improve on MPG cause it was heavy.

I bought a selection of real Suzuki jets as per the factory specs with airbox and suzuki filter (the P.O. had drilled the main jets to 2.1mm)

And it has run like shit ever since. I have tried a few combos of settings but result is average so in my case i don't quite know what went wrong haha

Edited April 4, 2021 by Joseph

[inazumarob]

Normally the idle adjustment on Suzuki carbs is done by a knurled adjusting wheel hanging underneath the carbs in the middle. Best carb synchroniser for sensible money is a Morgan Carbtune. The Gunson colortune is the glass plug you are looking for, harder to see flame colour with modern fuels though. Reset mixture adjusting screws to standard settings when fitting airbox and filter, normally located at bottom of carb body in a little tower casting.

 

[BushcrafterQC]

5 hours ago, inazumarob said:

Normally the idle adjustment on Suzuki carbs is done by a knurled adjusting wheel hanging underneath the carbs in the middle. Best carb synchroniser for sensible money is a Morgan Carbtune. The Gunson colortune is the glass plug you are looking for, harder to see flame colour with modern fuels though. Reset mixture adjusting screws to standard settings when fitting airbox and filter, normally located at bottom of carb body in a little tower casting.

 

Thanks! great input. Ill try and find the OEM number of turns in some manual somewhere. Funny how the stock airbox has some kind of cone restriction on the middle two cylinders, but is fully open on the outer carbs 1 and 4.

I ordered the K & L 18-2589 carb kit. hopefully it comes with the right jets.

[BushcrafterQC]

Anyone knows what this fitting is for on the fuel level sender? is it just a vent? its not plugged to anything, im guessing it vents in the stock airbox. I will probably find a generic hose to connect it to it.

[BushcrafterQC]

sorry for all the questions but with these vaccum petcocks, if it still lets a little fuel go trough when on ON position without getting vaccum. Could this cause any problems? thanks

[Gixer1460]

9 hours ago, BushcrafterQC said:

if it still lets a little fuel go trough when on ON position without getting vaccum. Could this cause any problems? thanks

 

9 hours ago, BushcrafterQC said:

I ordered the K & L 18-2589 carb kit. hopefully it comes with the right jets.

 

9 hours ago, BushcrafterQC said:

Anyone knows what this fitting is for on the fuel level sender? is it just a vent? 

Answers in order

1 - It will if the float valves in the carbs are worn as the floats won't be able to stop fuel flow. If the excess doesn't leak out on to the floor warning you of the problem, there is the potential to leak into the crankcase, diluting the oil and possibly hydro-locking when you try starting!

2 -  Hope you ordered 4 kits ! ! !

3 - Its a moisture drain - doesn't need connecting to anything.

[BushcrafterQC]

3 hours ago, Gixer1460 said:

2 -  Hope you ordered 4 kits ! ! !

Shure did, Thanks for the infos

[BushcrafterQC]

I got the carbs out and switched over to main jet 92.5 and pilot 40. The new pilot have 8 holes instead of 6. 

Back on the bike with the OEM airbox installed and I cant get it to start. I tought that with the stock size jets and airbox it would run fine but it wont budge. played with different pilot air settings. I got it to run for barely 2 seconds thats it. sounded like only 1 cylinder got running for a moment. got a big back fire. 

I wonder if the extra holes on the new pilot jet is causing the issue. Maybe something else on the carb was modified by the PO.... not shure. 
 

I really tought getting the stock jet size and removing the pods would solve this. I was running with the pods and drilled jets but, not all cylinders and was very rough

[BushcrafterQC]

Update****

I put the beat up oem mikuni pilots jets with 6 holes back in. readjusted the float heights, 3 where 2mm off. And fixed the stripped screw treads for the float bowl with an M5 helicoil. She's up and running! finally will get to ride it now. its running way smoother then when i bought it. Still has a few hick-ups here and there. adjusting the pilot screws doesn't seem to have any effect. I suspect there still another small vaccum leak somewhere. I will wait to receive the k&l kits to take the carbs off again and change the old seals. meanwhile i'm going to have some fun and see where it can bring me 

starting to get a feal for these old carbs. its fun. Happy i didn't go out to a dealer and buy a modern bike.

[Swiss Toni]

They’re good little bikes. Very underrated and almost bulletproof if you tend to the basics. Much more character than the ‘fly by wire’ types! 

[BushcrafterQC]

Well it might of been to good to be true :p. It was running fine yesterday for a small ride, air was cool. Today is hot and It ran real nice when the engine was cold (starts without the choke on the first turn over) but as soon as the engine warmed up it lost power died on me. wouldn't start until i waited 5 min for it to cool off a bit. had it surge on me a few times too.

This time when i put the carbs back together the float bowl gasket looked kind of terrible. no fuel leaks though. Caant wait for the postman to come with the k & L kits. hopefully thats all i need. I'm worried something else is going on here... 
 

newplugs look like this. They look rich right? 

 

Edited April 10, 2021 by BushcrafterQC
added picture of plugs

[TonyGee]

yeah very rich

[BushcrafterQC]

46 minutes ago, TonyGee said:

yeah very rich

I think it actually ran soo rich it fouled the plugs, and thats why it won't start. I guess I'll have to wait until i get the new jets to ride . 

Does anyone know where I can find the specs for the needle height for bs32? I'm pretty shure someone messed with those. I just need to find long enough circlip pliers to take them appart, mine are too short.

[TonyGee]

are all 4 plugs the same ? are the jets and air filter all standard ? 

[BushcrafterQC]

Just now, TonyGee said:

are all 4 plugs the same ? are the jets and air filter all standard ? 

for a bit i was running on 3 cylinders at one point (i would unplug the lead on cyl #4 with a colder header and no difference in RPM) That plug was dry with ash deposits. Then I ran it some more cold and they all came out black. I'm going to clean them right now and run it for a bit and check them gain to post a picture.

All jets are supposed to be the standard sizes, 92.5 main 40 pilot and 150 air. But the previous owner might have tempered with them. I'm waiting for some new ones in the k&l car rebuild kits. I reinstalled the OEM airbox beacause the P.O had pods on it. I removed the jets he installed and put some that where in a box of stuff that came with the bike. 

[TonyGee]

putting the standard airbox on with bigger jets will restrict the amount of air it needs and will run to rich. run it without the airfilter element and see if its better,  sound like the jets are way to big for a standard airbox. 

[BushcrafterQC]

well now i can't get it run much at all even cold, dies out at 3k, plugs aren't saying much #4 is a little wet and header is colder then others...

Ran it for about 4 min before it wouldn't respond to throttle and died out

19 minutes ago, TonyGee said:

putting the standard airbox on with bigger jets will restrict the amount of air it needs and will run to rich. run it without the airfilter element and see if its better,  sound like the jets are way to big for a standard airbox. 

good idea, theoretically i thought the jets i put back in where stock, but theres no telling if the PO drilled those as well, they looked way smaller then the drilled ones i removed when i removed the pods.

[TonyGee]

sometimes when a plug gets wet it wont spark again for some mad reason ??  have you got another set to try ? 

[BushcrafterQC]

30 minutes ago, TonyGee said:

putting the standard airbox on with bigger jets will restrict the amount of air it needs and will run to rich. run it without the airfilter element and see if its better,  sound like the jets are way to big for a standard airbox. 

No noticable difference with the air filter removed. What position should the clip on needle be for stock jets and airbox?

[TonyGee]

1 minute ago, BushcrafterQC said:

No noticable difference with the air filter removed. What position should the clip on needle be for stock jets and airbox?

no idea, you need to get a manual to find the stock setup for your model. 

[BushcrafterQC]

Just now, TonyGee said:

no idea, you need to get a manual to find the stock setup for your model. 

ive got a clymer, but theres no specs on it for needle adjustment, i'm guessing they might not be stock.

 

I'm going to give up on it for now and wait for the parts to get my head clear on whats really going on here. i hope k & L jets aren't garbage :p

Ill post an update when they are back on.

thanks for all the feedback!

[TonyGee]

just had a look on a parts diagram but it says pilot jets discontinued !!!!! so i couldn't find out the right size. what does your book say ? 

[BushcrafterQC]

4 minutes ago, TonyGee said:

just had a look on a parts diagram but it says pilot jets discontinued !!!!! so i couldn't find out the right size. what does your book say ? 

Clymer manual dosn't even list jet sizing but I found this guide that list jets for al BS carbs on suzuki

https://drive.google.com/file/d/1oqEjoQyS9F3xSr2-15yDZILxt7KzQje7/view?usp=sharing

[BushcrafterQC]

2 minutes ago, BushcrafterQC said:

Clymer manual dosn't even list jet sizing but I found this guide that list jets for al BS carbs on suzuki

https://drive.google.com/file/d/1oqEjoQyS9F3xSr2-15yDZILxt7KzQje7/view?usp=sharing

totally got mixed up, that guide doesn't list jet sizes, i found them on a website. will try and remember which one. sorry