The BST-40 Bible - Page 84

joefromsf · 03-04-2013, 08:43 PM

Quote:

Originally Posted by rockscrambler

yes, its in the pic "one of these". and is the smaller vacuum line, do you know what that connects to on the other end? thanks guys!

It doesn't connect to anything. It vents to air and is routed inside the outer frame back past the battery. It ends just past the battery.

ER70S-2 · 03-04-2013, 08:55 PM

Quote:

Originally Posted by joefromsf

It doesn't connect to anything. It vents to air and is routed inside the outer frame back past the battery. It ends just past the battery.

This one:

Goes here: Pay attention, the photos will mislead you. The 1st pic shows the hose goes to the left, the second shows the hose comes in from the left (backwards).

joefromsf · 03-04-2013, 08:57 PM

Quote:

Originally Posted by ER70S-2

That's what I get for trying to answer from memory. So it ends before the battery. I was right about venting to air though.

ER70S-2 · 03-04-2013, 09:01 PM

Quote:

Originally Posted by joefromsf

That's what I get for trying to answer from memory. So it ends before the battery. I was right about venting to air though.

Close enough.

motolab · 03-04-2013, 09:02 PM

Quote:

Originally Posted by joefromsf

It doesn't connect to anything. It vents to air and is routed inside the outer frame back past the battery. It ends just past the battery.

Interesting that CARB allows anything that vents fuel to go to the atmosphere. I would not have expected that.

Regards,

Derek

rockscrambler · 03-06-2013, 09:12 AM

thanks again guys

Kawidad · 03-07-2013, 08:00 AM

Quote:

Originally Posted by ER70S-2

This one:

Goes here: Pay attention, the photos will mislead you. The 1st pic shows the hose goes to the left, the second shows the hose comes in from the left (backwards).

That's how my 640 Enduro is set up.

Bullettwo · 03-13-2013, 07:57 PM

Thanks Laramie! I have only one question; can I substitute wine for the beer?

I'm thinking that margheritas and carburetor work might not be a good match.

wrk2surf · 03-13-2013, 10:24 PM

Quote:

Originally Posted by motolab

Unless I misunderstood rockscrambler's post, he had already identified the petcock vacuum line.

Regards,

Derek

P.S.: What's "205d" mean?

its some long story of a guy telling a story the second time.. ior something along those lines...long story short. you answer a quesion just before someone else has or post something that seems new but someone has beaten you to the punch...

By the way Derek thank you so much for the racing support I will be working on the bike for the next month and will update you!

Sane · 03-26-2013, 12:38 PM

Hello mates! I got Aprilia Pegaso,1994.,with two BST 33 carbs,and i am wondering,is this the right way to set float heigts??

http://www.apriliaforum.com/forums/s...hlight=jetting

Any sudgestions on how to properly clean an adjust these carbs?

Much obliged

clicheche · 04-01-2013, 02:56 PM

got the carb completely disassembled, and i took notes as to what seemed to be missing in comparison to the bst-40 bible.

i have no washer on the needle, aside from the white plastic one. the needle has only one ring for the snap ring to pop into, thus only offering one height.

i have no float weight on my float, just some clip assembly.
i have no needle valve, period. space was empty.

the idle jet is marked at 42.5, will need to increase to 47.5 with the airbox mod and new jet?
the main jet was marked with, from what i can tell, -782M(some box thing)Y-5
the o-ring for the main jet looks like there are 3 gouges out of them, though i am not certain. should this o ring be super smooth?

well there you have it. i have my bike inoperable, though i am nearing some measure of resolution with its fuel delivery system.
here's hoping i can get this carb in a happier state.

thanks a boatload for the info in this community everyone. its been cool

ps: i live at a really high elevation, do i want less gas/more gas to air ratio?
and furthermore, if i do the airbox mod, (allowing more air intake, nothing huge, just probly 600-800% bigger than the stock snorkel hole) would i want more fuel to air ratio regardless?

theGrinch · 04-01-2013, 05:03 PM

Quote:

Originally Posted by clicheche

got the carb completely disassembled, and i took notes as to what seemed to be missing in comparison to the bst-40 bible.

i have no washer on the needle, aside from the white plastic one. the needle has only one ring for the snap ring to pop into, thus only offering one height.

i have no float weight on my float, just some clip assembly.
i have no needle valve, period. space was empty.

the idle jet is marked at 42.5, will need to increase to 47.5 with the airbox mod and new jet?
the main jet was marked with, from what i can tell, -782M(some box thing)Y-5
the o-ring for the main jet looks like there are 3 gouges out of them, though i am not certain. should this o ring be super smooth?

well there you have it. i have my bike inoperable, though i am nearing some measure of resolution with its fuel delivery system.
here's hoping i can get this carb in a happier state.

thanks a boatload for the info in this community everyone. its been cool

ps: i live at a really high elevation, do i want less gas/more gas to air ratio?
and furthermore, if i do the airbox mod, (allowing more air intake, nothing huge, just probly 600-800% bigger than the stock snorkel hole) would i want more fuel to air ratio regardless?

If you open the airbox you change the pressure and will need to open the exhaust. What exhaust are you running?
What bike?

.

clicheche · 04-01-2013, 05:11 PM

not sure what exhaust i'm running.
'07 suzuki dr650

ER70S-2 · 04-01-2013, 05:45 PM

Quote:

Originally Posted by clicheche

got the carb completely disassembled, and i took notes as to what seemed to be missing in comparison to the bst-40 bible.

The bible starts off with a KTM carb, also a BST-40. As you've found there are some differences.

Quote:

Originally Posted by clicheche

i have no washer on the needle, aside from the white plastic one. the needle has only one ring for the snap ring to pop into, thus only offering one height.

Correct.

Quote:

Originally Posted by clicheche

i have no float weight on my float, just some clip assembly.
i have no needle valve, period. space was empty.

It's hiding in here.

Quote:

Originally Posted by clicheche

the idle jet is marked at 42.5, will need to increase to 47.5 with the airbox mod and new jet?

No, stay with the 42.5

Quote:

Originally Posted by clicheche

the main jet was marked with, from what i can tell, -782M(some box thing)Y-5

Stock is a 140 and should be stamped on the jet. 150, 160 are common for a jet kit.

Quote:

Originally Posted by clicheche

the o-ring for the main jet looks like there are 3 gouges out of them, though i am not certain. should this o ring be super smooth?

Some one else will have to help here. The main jet doesn't have an o-ring.

Quote:

Originally Posted by clicheche

well there you have it. i have my bike inoperable, though i am nearing some measure of resolution with its fuel delivery system.
here's hoping i can get this carb in a happier state.

thanks a boatload for the info in this community everyone. its been cool

Hang in there, we'll get you through this.

Quote:

Originally Posted by clicheche

ps: i live at a really high elevation, do i want less gas/more gas to air ratio?

Technically, you want the same ratio. Since we have less air at altitude, we need smaller jets.

Quote:

Originally Posted by clicheche

and furthermore, if i do the airbox mod, (allowing more air intake, nothing huge, just probly 600-800% bigger than the stock snorkel hole) would i want more fuel to air ratio regardless?

How high? I live and ride at 6000+ feet. My DR runs better with a 135MJ here.

Don't worry about your exhaust for now, it's the least of the issues.

clicheche · 04-01-2013, 09:19 PM

just realized today it was a ktm carb!

noticed the hiding float weight. makes sense
leaving the fuel screw at 42.5 is fine for idling?
i noticed the stamp on the nut for the main jet, not on the jet itself. 140 it was.

the washer i said was for the main jet, was definitely for the jet slide support (white plastic piece), not the jet itself

i live @ 3500 feet above sea level.

i only cut out about 150% more of the initial air intake opening. did you do an air box mod?

any opinion on the premise of a k&n air filter for more air? would it help with the thinner air at high elevation?

i threw on one tiny washer against the needle spacer in the carb... hope it won't be too much of an issue. and i drilled out the slide for the slide suction to respond faster to throttle.

also put together this manual choke, as my cable was seized inside the carb.

everything's put back together, next up is the direct power to the headlight, and i'm about done for this year. changed the plugs as well.
the bike only had 12xxxkms on it. the plugs were black. not oily black, but burnt black... sign of being too rich right?

the largest exhaust hose from the carburetor, is it required to be that long? can i move it out of the way? for more air flow to the air box? i saw a post where someone moved it out of that area at any rate...

thanks a ton for the response, it gave me the go ahead to just check it out and go ahead. i had problems with it stalling and it had trouble starting from time to time. usually cold starts as usual. we'll see how it goes this year!

04-01-2013, 02:56 PM	#1256
clicheche Adventurer Joined: Apr 2013 Location: Calgary, Alberta, Canada Oddometer: 71	AHHHHHHHHHHHHHHHH! wicked thread, but i need help with the state of my carb! got the carb completely disassembled, and i took notes as to what seemed to be missing in comparison to the bst-40 bible. i have no washer on the needle, aside from the white plastic one. the needle has only one ring for the snap ring to pop into, thus only offering one height. i have no float weight on my float, just some clip assembly. i have no needle valve, period. space was empty. the idle jet is marked at 42.5, will need to increase to 47.5 with the airbox mod and new jet? the main jet was marked with, from what i can tell, -782M(some box thing)Y-5 the o-ring for the main jet looks like there are 3 gouges out of them, though i am not certain. should this o ring be super smooth? well there you have it. i have my bike inoperable, though i am nearing some measure of resolution with its fuel delivery system. here's hoping i can get this carb in a happier state. thanks a boatload for the info in this community everyone. its been cool ps: i live at a really high elevation, do i want less gas/more gas to air ratio? and furthermore, if i do the airbox mod, (allowing more air intake, nothing huge, just probly 600-800% bigger than the stock snorkel hole) would i want more fuel to air ratio regardless?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: .
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

03-06-2013, 09:12 AM	#1251
rockscrambler rock climber Joined: Jan 2013 Location: yosemite Oddometer: 3	thanks again guys

03-13-2013, 07:57 PM	#1253
Bullettwo Adventurer Joined: Dec 2007 Location: Southern Oregon Coast Oddometer: 43	Thanks Laramie! I have only one question; can I substitute wine for the beer? I'm thinking that margheritas and carburetor work might not be a good match.

03-26-2013, 12:38 PM	#1255
Sane n00b Joined: Mar 2013 Oddometer: 1	Hello mates! I got Aprilia Pegaso,1994.,with two BST 33 carbs,and i am wondering,is this the right way to set float heigts?? http://www.apriliaforum.com/forums/s...hlight=jetting Any sudgestions on how to properly clean an adjust these carbs? Much obliged

04-01-2013, 05:11 PM	#1258
clicheche Adventurer Joined: Apr 2013 Location: Calgary, Alberta, Canada Oddometer: 71	not sure what exhaust i'm running. '07 suzuki dr650

04-01-2013, 09:19 PM	#1260
clicheche Adventurer Joined: Apr 2013 Location: Calgary, Alberta, Canada Oddometer: 71	just realized today it was a ktm carb! noticed the hiding float weight. makes sense leaving the fuel screw at 42.5 is fine for idling? i noticed the stamp on the nut for the main jet, not on the jet itself. 140 it was. the washer i said was for the main jet, was definitely for the jet slide support (white plastic piece), not the jet itself i live @ 3500 feet above sea level. i only cut out about 150% more of the initial air intake opening. did you do an air box mod? any opinion on the premise of a k&n air filter for more air? would it help with the thinner air at high elevation? i threw on one tiny washer against the needle spacer in the carb... hope it won't be too much of an issue. and i drilled out the slide for the slide suction to respond faster to throttle. also put together this manual choke, as my cable was seized inside the carb. everything's put back together, next up is the direct power to the headlight, and i'm about done for this year. changed the plugs as well. the bike only had 12xxxkms on it. the plugs were black. not oily black, but burnt black... sign of being too rich right? the largest exhaust hose from the carburetor, is it required to be that long? can i move it out of the way? for more air flow to the air box? i saw a post where someone moved it out of that area at any rate... thanks a ton for the response, it gave me the go ahead to just check it out and go ahead. i had problems with it stalling and it had trouble starting from time to time. usually cold starts as usual. we'll see how it goes this year!