I got a new tank and filters so fuel starvation and rusty/gunky gas is solved.
The filters i am using are the same i used before. they are for a gravity fed car. they provide enough flow, at least for idling and filling the bowls.
89 Petcock inverted and vaccum diaphragm blocked. oring changed to viton. http://gs-500.info/index.php?title=Convert_petcock_from_vacuum_to_manual
The bike only starts with full choke which is expected, but after 2 minutes if i put the choke at 70% it starts to die.
As it gets warmer is more dificcult to start and tends to rev up way higher. cant make it idle. zero power
as soon i give some throttle it dies..
First start: https://imgur.com/035UDX8 (https://imgur.com/035UDX8)
following starts it was revving higher and higher, i tried to open the throttle to 60% to make the needle raise , it dies.
KN lunchbox with stock 89 pipe and header
2008 3 circuit carburetors with PAIR solenoid removed and vaccum lines disconnected and blocked ports.
TPS disconnected.
Jets:
20 pilot
60 mid
130 drilled with 1,4 mm bit
needle shimmed about 1mm (will check this later )
2.5 turns out at pilot mix
Now i will clean them again as im sure that a few months sitting and rusty gas could have clogged something
Main question : how much to shim the needle
i think these were California US carbs with PAIR system,TPS, 130 mains and 5DH60 needle.
Aside from cleaning, how you would tune them?
before removing them i will try the same start and spray wd40 to the boots to check if i have a vaccum leak.
http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting-LeanOrRich? (http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting-LeanOrRich?)
http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting
according to this:
stock exhaust + kn lunchbox:
pilot 20
mid-main 62.5 or 65
with no washers
main 142.5
washers 2
turns 3
people 2
excellent performance, but
62.5 mid needed both washers
--------------------------------------------------------
Cant understand if washers are needed if i have a 62.5 mid
if it is 60 mid main washers are necessary i suppose.
excellent performance ??
or worth ditching the KN lunchbox and putting the airbox with new boots?
2 intake (carb to airbox) boots were pricier than a kn lunchbox and thats why i decided to change it and remove the airbox.
Well. I have two exhaust headers bolts missing. They flew to oblivion.
I will replace with Allen bolts and loctite, any advice?
I don't have studs , I have bolts that screw to the cylinder head.
Something strange, right cilinder was leaking through the exhaust.
It leaved a stain in the floor, will see if it is oily or it evaporates tomorrow.
Oil seems in good shape, clean as honey in the dipstick. No apparent odor to gas, same level.
ooooh... immediately change the drilled out main jet.... There s not way that they are the same, or that they are near any real spec...
The jets are not expensive and you can even order them from ali express. Dont bother changin the mid jet, Its actually just the starting jet, people get confused by the terms "mid", its not.
Runnning badly on a GS500 is usually because its too rich... go back to stock (exhaust, air filter, carb, etc) and then start from there
for example this: ?https://es.aliexpress.com/item/1005002697991041.html (https://es.aliexpress.com/item/1005002697991041.html)
I tried to get the English url but keeps me redirecting.
choosing 130, 132.5 135, 137.5 and 140 its ok for lunchbox and future airbox also?
or it is best to order from 125 to 145?
As I have to order in 10 sizes y could order 5 pairs or 10 pairs
Found rubber boots locally at good price.
part 4
https://www.partzilla.com/catalog/suzuki/motorcycle/2008/gs500f/air-cleaner
13881-01D60
https://www.partzilla.com/product/suzuki/13881-01D60
but seems thath for 89-96 models there is other code for 89model
https://www.partzilla.com/catalog/suzuki/motorcycle/1989/gs500et/air-cleaner
13881-01D01
https://www.partzilla.com/product/suzuki/13881-01D01
that seems strange because 99,00,01 had the older carb.
Are both rubber boots the same?
my concern is that maybe with the change of carburetor the rubber diameter changes,
are the older an newer carbs equal in air filter side diameter?
took out carbs, compared with older ones.
Older ones seems to have 1 mm more and the top facing part is oval with a little vent.
3 circuit newer ones are completely round.
Will change the intake cylinder head orings that are between the rubber and the valve ports.
Carb is out and in cleaning process.
Carbs cleaned with new intake orings.
2.5 turns out.
Started at first time and idling really tidy.
Now I need to do some test rides.
It never ran so well, the intake boot orings made all the difference.
Still at 2.5 turns out, maybe I will move it a quarter out in a few days but first I want to test the first portion of the throttle response.
It is far from perfect but is better than ever.
Maybe I will end all this nightmare of having the perfect throttle response if I can t dial it right and put the airbox again when my new jets arrives.
If someone is still here.
Which jets should I choose?
Airbox
130 , 132.5 and 135 or 127.5?
Kn lunchbox
140 and 142.5 or 137.5
I need to choose 5 pairs.
Stock is always best. BUt I would also buy one smaller size, its is a great help of you need to trouble shoot and *know* if it gets better or worse when leaner rather than guess.
(https://i.imgur.com/dJLPCkz.png)
Where are you based thougth I could pop some jets in the post for you for shipping, but coming form ali might still be cheaper. I'd need to check exactly what I have but I had a decent selection when I ordered 10.
Quote from: Armandorf on March 15, 2023, 12:53:48 AMIt never ran so well, the intake boot orings made all the difference.
Still at 2.5 turns out, maybe I will move it a quarter out in a few days but first I want to test the first portion of the throttle response.
It is far from perfect but is better than ever.
Maybe I will end all this nightmare of having the perfect throttle response if I can t dial it right and put the airbox again when my new jets arrives.
If someone is still here.
Which jets should I choose?
Airbox
130 , 132.5 and 135 or 127.5?
Kn lunchbox
140 and 142.5 or 137.5
I need to choose 5 pairs.
You need 5 sizes ? Some type of minimum order ?
Stock bike with pipe or stock pipe runs right with 132.5 and 20 pilots.
K&N and pipe is 147.5. You could also get 62.5 mid mains. I would defer to others here as to what they run with K&N and stock pipe. If you can get a pilot also in the mix, get 20's - nearly all set up's use 20 pilots.
Cool.
Buddha.
Quote from: The Buddha on March 16, 2023, 05:35:19 AMYou need 5 sizes ? Some type of minimum order ?
Stock bike with pipe or stock pipe runs right with 132.5 and 20 pilots.
K&N and pipe is 147.5. You could also get 62.5 mid mains. I would defer to others here as to what they run with K&N and stock pipe. If you can get a pilot also in the mix, get 20's - nearly all set up's use 20 pilots.
Cool.
Buddha.
i already have 20 pilots. 60 mid main and a poorly drilled main that should be around 142.
now within the first half of the throttle, seems very good but after that , going at medium rpms if i want to accelerate (more than 70%) i get rumbliness and a lot of noise and i can feel the bike struggles to climb up rpms, it continues to accelerate but like if i were going very fast with wind against me.
any way my compression is not tested so..
first i will check valves.
---
Yes, it is the minimum order, the ali express link i posted before that sells in dezens, 10 or 20 jets.
i could pick 10 sizes x2, maybe i wil do that.
midmain
62,5 (already have 60)
airbox
127,5 130 132,5 135
kn
137,5 140 142,5 145 147,5
and then i have all the sizes i should need, so tuning should be easier.
----------------------
as for the jet sizes, i think the only rear answer is to try out each size.
i know stock exhaust with kn lunchbox is a bit odd. my exhaust has a poked hole in the side(PO) , rear axle went through it so is a bit more free flowing and rumbly than stock :icon_lol:
@The Buddha Now that i have you here, i will take the opportunity of making some questions that i always had on my mind.
i have the older carbs sitting in a bucket, they need a few parts, the PO had them in poor condition.
Imagine, for example, a different slide coil in one side. and more things like that.
i bought the newer ones(2008 used from ebay, pinwall_cycle_parts) because the one i had was pretty beaten and i didnt trust it.
the new ones were never opened but beaten too,i imagine when taking them out.
A dent in the top and a broken choke tab. Luckily zipties fixed that .
in a future i would like to make a rebuild of the older carb. Is it worth it? i already have the new carb to airbox boots.
whats your opinion about the differences between the two models bst33 an bsr34? is the model stamped in some place of the carb body? can't find it.
some say that only with the older carb you can get the claimed "52 hp", i know that at the wheel is just a bit over 30.
i suppose that with a proper rejet you should get the same HP and torque...is that the case?
are the newer ones more smooth or economical? any advantages and downsides of each model?
why so many people say mid main is not that important as if it were like a choke enrichment jet?
how many km the black plastic slides live?
i also read that for limiting output they put a 135 instad of 130. i will post the link here. is a bit odd.
i knew restrictor were giant washers limiting airflox, in Spain is a common practice for the 25kW restriction for begginers license.
https://forum.gs-500.de/archive/index.php/t-12739.html
Quote from: herennow on March 15, 2023, 01:00:45 PMStock is always best. BUt I would also buy one smaller size, its is a great help of you need to trouble shoot and *know* if it gets better or worse when leaner rather than guess.
(https://i.imgur.com/dJLPCkz.png)
Where are you based thougth I could pop some jets in the post for you for shipping, but coming form ali might still be cheaper. I'd need to check exactly what I have but I had a decent selection when I ordered 10.
can i use your image for the cleaning post? great info.
there is any chance you have something similar for the older carb, bst33?
thank you for the offer, but i am in Argentina so aliexpress will be cheaper.
there are a few parts that i can t still find here, maybe in the future i will ask one of you if you can grab them and then ship them in a flat rate box.
That would be of great help.
The newer carbs use different jets. So you need to decide which way you're going with the old vs new carbs before that jet order.
Though I would think the 125 standing for hole dia of 1.25mm would have been mikuni's practice all through. The outside is what's different. Has someone put new jets in the old carb ? Do they translate straight across like 125=125 ? Pilots are completely different wont even thread in and cant caliberate - 40 vs 20 Like WTF. No mid mains in older ones.
TBH, I find the older carbs easier to tune, but once its all fiddled with newer carbs work better by a shade.
Either will work. use the set that's the least defective LOL.
52 hp is available when you set the engine to GSXR600 or something like CBRFZR7 or something like that (handle of a freq posting member here) has done. CBR1000RR engine in the GS.
Cool.
Buddha.
I know older carbs uses other jets.
I plan to use the airbox with the newer carbs first.i need the 02+ airbox boots.
I used the bike for 6 rides and ran about 60km.
It runs really well when hot.
Choke doesn't up the rpm at cold.
When it starts to warm up, after 3 or 4 minutes a blip of throttle puts at 4k rpm steady with choke.
Noticed slight tendency to be jumpy coming of idle in 1st or in 2nd at 2k or less. I know it's a motorbike and it's not meant to be ridden like a car.
But looking for optimal mixture screw adjustment I want to feel the carburetion for now.
I also have occasional pops when it gets warmer(audible through lunchbox)mainly at idle. They seem to be like misfires, they are like dry P s that you can do with your mouth, filling with air and releasing abruptly opening your lips.
I know it's difficult to describe so I will try to record it.
Spark plugs could be also but I will not change them till I change piston and rings.
I'm at 2.5 turns with a 20 pilot.
I guess I will put it at 3 and see if it changes.
My gut tells me to close it tough.