Air-mixture screws were set differently at the factory

[Darkstar]

...used a .018" guitar string bent into a "L" shape on the end to "pick" them out

Thanks for the tip! I'm going to save this as my last resort thought, after checking the easier things

it's WAY easier to do it with them off and upside-down on the bench

Sorry, I was referring to the jet needle that I raised the height on. Pretty sure I can work on that from the top.

[mr72]

I'll spray some carb cleaner around while it's running to see

DO NOT SPRAY CARB CLEANER TO CHECK VACUUM LEAKS!!!

It will degrade rubber parts and will absolutely dissolve the rubber diaphragms in a GS's carbs.

Use some other method. Something inert. Water. Smoke. Or just go through everything and replace everything that might cause a vacuum leak.

[The Buddha]

- One float bowl was at 10mm, the other at 13mm. Both are now set to 13.

I never understood this 13.6 crap. Fuel should be @ the top of the bowl via U tube method.
Cool.
Buddha.

[Darkstar]

DO NOT SPRAY CARB CLEANER TO CHECK VACUUM LEAKS!!!

Gotcha. I'll use the cigar trick

[Suzuki Stevo]

DO NOT SPRAY CARB CLEANER TO CHECK VACUUM LEAKS!!!

IIRC WD40 works for that.

[qcbaker]

IIRC WD40 works for that.

Doesn't WD40 also degrade rubber?

[Darkstar]

Doesn't WD40 also degrade rubber?

Oily, some use brake cleaner. Also I see people using an unlit propane pencil torch, vidoes show is being done in short sessions so it doesn't pool and ignite.

[Suzuki Stevo]

Doesn't WD40 also degrade rubber?

No, there was a myth going around not to use it to clean an O-Ring chain because it wanked out the rubber, to the best of my knowledge that was disproven years ago.

[qcbaker]

Doesn't WD40 also degrade rubber?

No, there was a myth going around not to use it to clean an O-Ring chain because it wanked out the rubber, to the best of my knowledge that was disproven years ago.

I guess you're right. Looking at their website, it says it's safe to use on rubber. And apparently, some guy on a dirtbike forum soaked a rubber chain o-ring in WD40 for a month and it had no real effect: https://www.thumpertalk.com/forums/topic/534631-does-wd40-hurt-o-rings-a-test/

[J_Walker]

There's still lots of motorcycle forums who talk down WD40 for cleaning carbs... I wish they would stop but some people just don't read MSD sheets...

[mr72]

Regardless, for finding vacuum leaks, there are better solutions than WD40. And for carbs with rubber diaphragms, carb cleaner should be avoided at all costs. Once you tear down the carbs to metal parts only then carb cleaner works great for cleaning. But for vacuum leaks, use something else. Water is way cheaper and works.

[Darkstar]

Sounds like the better solution. I'll give it a shot after the blizzard stops here and updated you guys. thanks

[The Buddha]

You do realize that if it has a vacuum leak @ the boots or even anywhere else, you'd have issue idling and wont even start easy with the choke ... but rev fine when blipped right ?

You issue is else where. Maybe a slide is stuck open. Or something like it. I'll still bet floats.

Cool.
Buddha.

[Watcher]

I worked as an air-tech at a paintball shop for several years and WD40 would absolutely degrade rubber.

It won't dissolve it like carb cleaner does, but it does have an affect on o-rings that is pretty profound.
A once stiff oring would, after being soaked in WD, turn soft and stretchy almost like a rubber band, and would invariably cause leaks and/or poor performance.
People would come in all the time complaining of a leaky gun or one that jams up or malfunctions and it would reek of WD.  We'd confirm with the customer that WD was used as a lubricant.
Strip the whole gun, meticulously clean it, replace EVERY seal, lube with air tool oil, and send the customer out $50 lighter.



Use a spray-bottle of WATER to check for vacuum leaks.

[J_Walker]

I worked as an air-tech at a paintball shop for several years and WD40 would absolutely degrade rubber.

It won't dissolve it like carb cleaner does, but it does have an affect on o-rings that is pretty profound.
A once stiff oring would, after being soaked in WD, turn soft and stretchy almost like a rubber band, and would invariably cause leaks and/or poor performance.
People would come in all the time complaining of a leaky gun or one that jams up or malfunctions and it would reek of WD.  We'd confirm with the customer that WD was used as a lubricant.
Strip the whole gun, meticulously clean it, replace EVERY seal, lube with air tool oil, and send the customer out $50 lighter.


Use a spray-bottle of WATER to check for vacuum leaks.

I'm not disagreeing with you on the paintball o-rings, but carb orings are a different type of rubber, meant to be around gasoline.. a pretty volatile chemical, I dont think anything in WD40 is as volatile as regular gasoline. paintball equipment is meant to hold air pressure and thats it, so they're gonna use cheap-o o-rings.

[Watcher]

I worked as an air-tech at a paintball shop for several years and WD40 would absolutely degrade rubber.

It won't dissolve it like carb cleaner does, but it does have an affect on o-rings that is pretty profound.
A once stiff oring would, after being soaked in WD, turn soft and stretchy almost like a rubber band, and would invariably cause leaks and/or poor performance.
People would come in all the time complaining of a leaky gun or one that jams up or malfunctions and it would reek of WD.  We'd confirm with the customer that WD was used as a lubricant.
Strip the whole gun, meticulously clean it, replace EVERY seal, lube with air tool oil, and send the customer out $50 lighter.


Use a spray-bottle of WATER to check for vacuum leaks.

I'm not disagreeing with you on the paintball o-rings, but carb orings are a different type of rubber, meant to be around gasoline.. a pretty volatile chemical, I dont think anything in WD40 is as volatile as regular gasoline. paintball equipment is meant to hold air pressure and thats it, so they're gonna use cheap-o o-rings.

There's actually a variety of materials we use in the guns, including the Buna material commonly used in gasoline applications, and in some cases the seal needs to hold thousands of PSI.
Paintball guns usually run off of around an 800psi input, sometimes more, sometimes less, and I've personally owned a gun that was designed to withhold and operate at pressures up to 3000psi, which I have, and it does.  The o-rings aren't what I'd call "cheap".

But I saw what I saw, and in my experience it wasn't just Urethane orings that were negatively affected by the wrong kind of lube.

[Darkstar]

if it has a vacuum leak you'd have issue idling...

my idle is fine, so that's one test checked off the list and a reason not to buy a cigar...much obliged. now if you tell me that i gotta pull the o-ring from the mixture screw threads, id use other words.    i'll put tube float level test at the top of my list.

[mr72]

if you tell me that i gotta pull the o-ring from the mixture screw threads, id use other words.  

Better get those words ready.

Eventually. It is going to have to be done.

[Darkstar]

Big steps forward today! I cleared the snow off to take a took and found two problems: first the airbox boots were mis-aligned so I think there was air leaking there, and second was that I routed vacuum tubes under the large breather hose, so with the tank on it was pushing down on them. After fixing both and taking the tank off, I ran it off a funnel. Spraying water all over it did nothing, so no air leaks there. Next, I set both pilot mixture screws to 2, adjusted both idle, and the the carb sync. After that, it sounds much much better. Throttle response is super quick, and it seems like it's breathing well because WOT runs up to redline much faster than before, and there's no hanging. I'm certainly out of the fubar stage, but i won't know until the roads dry and I take it for a ride.

The only major flaw is still the enricher. When I crack it open at idle, RPM's rise for a split second, and then bog out. I guess this means the idle circuit is still rich, but it starts effortlessly, even in 30F weather. I wonder if it'll be a problem in the summer though.

I attempted the float-tube-level-test, but discovered my tube was too wide for to seal. So, next up is a home depot run for that before I try again. I also decided not to pull the jet needle just yet. I will eventually because my c-clips are spinning, and I learned today that is very risky.

[mr72]

Sounds like it's still too rich on pilot.

Should require the choke to start AT ALL and within 15 seconds or so it should rev up to like 5K rpm while on choke ("fast warm up"). Then it should run fine with choke off after running like this about 30-60 seconds.

It it starts with no choke and dies when you turn on choke then it's too rich.

There are a number of reasons why it might be too rich, but I doubt it is your idle screw settings. Could be leaking o-rings on the pilot needle/idle mix adjuster or float level too high or stuck slide/main needle etc.

Sounds like your other problem was pinched vacuum line so the vac. petcock was not delivering fuel.