GStwin.com GS500 Message Forum

Main Area => General GS500 Discussion => Topic started by: GSinTN on May 31, 2022, 05:13:13 PM

Title: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on May 31, 2022, 05:13:13 PM
https://imgur.com/a/A1Bvpi4

I broke this when upgrading my jets. Do i need to replace it or can i plug it? If i need to replace it what is the name of it and does anyone know where to get it?
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: SK Racing on June 01, 2022, 02:20:10 AM
I doubt that it's available separately. That plastic part doesn't show up with a part number on Bikebandit.com

It should be an easy fix, though. Use a piece of brass tubing that fits inside and glue the broken piece back on with J-B Weld. The tubes are part of a closed vacuum system and if there is a leak, the main petcock won't open. In that case you'll only get gas through with the petcock lever in "prime" position. (that is rubbish - please ignore)

This is my understanding anyway. Maybe Buddha or someone else more knowledgeable than me can confirm.

Brass tubes are usually available at good hobby shops, or order directly from KS Metals: ksmetals.com/collections/brass (http://ksmetals.com/collections/brass).
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: mr72 on June 01, 2022, 05:04:37 AM
JB weld will not stick to that plastic. Permatex makes a plastic weld that may stick if you can get it completely clean, like with acetone. Or you may be able to get some abs adhesive for abs plumbing to work.

There's not much that will stick to both brass and abs plastic. I like the brass tubing idea but maybe try to get a piece that is an interference fit and support it with super glue.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: SK Racing on June 01, 2022, 05:32:01 AM
I think you're right about that. I was guessing JB Weld, but have never used it myself. Now that you mention it, I seem to remember that it works well on metal.

I wonder if a solvent-based adhesive will work. Probably not, since that plastic part was made to withstand gasoline (solvent to some extent).

Maybe epoxy will do the trick. I've used 15min epoxy for automotive repairs (plastic water bottle) before and it handled the temperature well.

Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 01, 2022, 06:49:44 AM
Thank you to both of you for your ideas. Not the answer i was hopin for though 😂 i had a feeling it wasnt a part i could order because none of the diagrams gave it a number. I wonder if anyone has an old carburetor they dont need that i can pull it off of.


On a side note, i dont see how the vaccum even works. How does it pull fuel when the vaccum line is above the diaphragm. Doesnt the air from the intake go over the hole and in effect pull fuel from the jets? Maybe its to help the needle rise when throttling? Idk im just rambling on but i dont see how it can be that important if bikes are made without them (its all part of the PAIR system is it not?)
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: The Buddha on June 01, 2022, 07:01:22 AM
Quote from: SK Racing on June 01, 2022, 02:20:10 AM
I doubt that it's available separately. That plastic part doesn't show up with a part number on Bikebandit.com

It should be an easy fix, though. Use a piece of brass tubing that fits inside and glue the broken piece back on with J-B Weld. The tubes are part of a closed vacuum system and if there is a leak, the main petcock won't open. In that case you'll only get gas through with the petcock lever in "prime" position.

This is my understanding anyway. Maybe Buddha or someone else more knowledegable than me can confirm.

Brass tubes are usually available at good hobby shops, or order directly from KS Metals: ksmetals.com/collections/brass (http://ksmetals.com/collections/brass).

Vacuum for the petcock comes off the carb body by the manifold and its usually a metal fitting. This crap may have vacuum but really is a emissions BS thing.
Cool.
Buddha.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 01, 2022, 07:28:24 AM
Quote from: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.

I will try it! My dumbass ordered 2 sets of jets....but only 1 jet each. Like i ordered 1 of each 20,62.5,65,142.5, and 145. Instead of 2. So when they come in i will install and then run without the line. Also, should i take the other off and see how it runs? Ive only had a gs500 for 2 months and its my first bike, so im new to the mechanical side of things. But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: SK Racing on June 01, 2022, 07:43:31 AM
Quote from: The Buddha on June 01, 2022, 07:01:22 AM

Vacuum for the petcock comes off the carb body by the manifold and its usually a metal fitting. This crap may have vacuum but really is a emissions BS thing.
Cool.
Buddha.

Good to know, thanks.  :thumb:

I hate all the "unnecessary" plumbing on the carbs. If I knew what is not needed, I'll gladly remove it. My 2004 F-model doesn't have PAIR, but it does have this crap.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: Bluesmudge on June 01, 2022, 08:41:46 AM
I don't think you even have to plug it. I have mine open to the atmosphere and my bike runs great. They should only do anything when a vacuum is present.
I also have a theory that the entire diaphragm cap can be replaced with the '01 - '02 cap to clean things up.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: mr72 on June 01, 2022, 11:28:24 AM
I wasn't commenting on the merit of repairing it, or necessity. I pulled all of the evap stuff off of all of my bikes that had it. But if it's a vacuum port that's connected to the rest of the vac system, you'll want to plug it. In that case, I'd use the Permatex plastic welder to fill it, it works very well on ABS. I've used it to make significant and load bearing repairs on my Triumph bodywork. It will fill the hole all by itself.

Regular epoxy won't stick to it without special treatment that's nearly impossible to do on that kind of part, and even then the bond is very suboptimal. ABS adhesives are solvent-based stuff that actually dissolves two pieces of like plastic together, and even plain old MEK will work for that as long as it's ABS or polystyrene and you use a plug of the same material that's essentially a perfect fit. FYI good old Testors Model Glue is MEK with some kind of solids in it to provide gap filling, and might work all by itself. Super glue works well too (CA glue) but it has poor gap filling so it would need to be supported with a plug. If I was going to use a CA glue, I'd probably tap the hole and super glue a grub screw into it.

That's about 220 words more than you ever wanted to know about gluing plastics.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: chris900f on June 01, 2022, 04:30:46 PM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

I have been experimenting with the TPS, and I've come to the conclusion that it acts as a limiter/governor at engine speeds below 4k, probably for emissions reduction.
Looking at the ignition system diagram and explanation given in the service manual (2003 section, when TPS was first introduced). It says that the TPS voltage goes to a
"vibrating crystal" whose output modifies the signal. So it is an analog system with a quartz crystal, therefore the ignition curve is hardwired, and not a digital map. AFAIK
in all electronic analog systems, all the advance is set at the rotor and the box delays that signal (like a guitar stomp box) based on RPM and full advance just means zero delay.

So yes you can unplug the TPS, and I haven't noticed any ill effects, although you may lose a few MPG.

Where are you located? I thought only the UK/Euro bikes got the PAIR system with the tubes going from the engine block into the exhaust headers (fugly too, lol)
If you don't have all that extra exhaust plumbing, all you need to do is put a small air filter on the hose coming from the breather on top of the valve cover, to run
without an airbox.

Title: Re: Do i need this vaccum line on top of diaphram?
Post by: The Buddha on June 02, 2022, 07:09:37 AM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
Quote from: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.

I will try it! My dumbass ordered 2 sets of jets....but only 1 jet each. Like i ordered 1 of each 20,62.5,65,142.5, and 145. Instead of 2. So when they come in i will install and then run without the line. Also, should i take the other off and see how it runs? Ive only had a gs500 for 2 months and its my first bike, so im new to the mechanical side of things. But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

What's worse is you didn't ask me for jets. Your setup and the jets you need are reaearched and proved out by O2 sensors.
142.5 is not one I have proved, but others here have tried it. 145 isn't needed for anything. 147.5 is a required size for WFO (K&N and pipe). And usually we do 20/147.5 in that case.
Cool.
Buddha.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: Bluesmudge on June 02, 2022, 08:52:38 AM
Quote from: chris900f on June 01, 2022, 04:30:46 PM
I thought only the UK/Euro bikes got the PAIR system with the tubes going from the engine block into the exhaust headers (fugly too, lol)


The United States got the PAIR system too. At least my 2006 had it. Not sure if 2004 and 2005 had it but I would assume they did.

I can also confirm that unplugging the TPS seems to have no ill effects.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 02, 2022, 01:43:26 PM
Quote from: The Buddha on June 02, 2022, 07:09:37 AM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
Quote from: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.

I will try it! My dumbass ordered 2 sets of jets....but only 1 jet each. Like i ordered 1 of each 20,62.5,65,142.5, and 145. Instead of 2. So when they come in i will install and then run without the line. Also, should i take the other off and see how it runs? Ive only had a gs500 for 2 months and its my first bike, so im new to the mechanical side of things. But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

What's worse is you didn't ask me for jets. Your setup and the jets you need are reaearched and proved out by O2 sensors.
142.5 is not one I have proved, but others here have tried it. 145 isn't needed for anything. 147.5 is a required size for WFO (K&N and pipe). And usually we do 20/147.5 in that case.
Cool.
Buddha.

I just went by the wiki "K&N Pod or Lunchbox Air Filter + Sports Exhaust = 20/65/145"

I have pilot/mid-main/ main jets on my bike.

Just got the k&n lunchbox and got a dominator gp1 exhaust on the way. My bike already had a really thin washer and a medium thickness washer on my carb needles.

What jets would you have selected differently with those mods?
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 02, 2022, 01:46:35 PM
Quote from: chris900f on June 01, 2022, 04:30:46 PM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

I have been experimenting with the TPS, and I've come to the conclusion that it acts as a limiter/governor at engine speeds below 4k, probably for emissions reduction.
Looking at the ignition system diagram and explanation given in the service manual (2003 section, when TPS was first introduced). It says that the TPS voltage goes to a
"vibrating crystal" whose output modifies the signal. So it is an analog system with a quartz crystal, therefore the ignition curve is hardwired, and not a digital map. AFAIK
in all electronic analog systems, all the advance is set at the rotor and the box delays that signal (like a guitar stomp box) based on RPM and full advance just means zero delay.

So yes you can unplug the TPS, and I haven't noticed any ill effects, although you may lose a few MPG.

Where are you located? I thought only the UK/Euro bikes got the PAIR system with the tubes going from the engine block into the exhaust headers (fugly too, lol)
If you don't have all that extra exhaust plumbing, all you need to do is put a small air filter on the hose coming from the breather on top of the valve cover, to run
without an airbox.

Im in TN, USA. But im assuming my 07 500f was a california bike. And since i have the airbox i gotta put a filter on hose coming from breather from valve cover it seems
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: chris900f on June 02, 2022, 11:09:14 PM
The California code is P-33, the rest of the USA is P-03, Canada is P-28.

We all get the same jetting, and we all have the "pre-set" pilot screws. P-33's also get a leaner needle

The EU P-19's got the best set-up with a 135 main, a richer adjustable needle and adjustable pilot screws.

(https://iili.io/3WLDRR.png)


Also, re your last post if you keep the airbox you don't need a filter for the breather; just connect the hose
to the box.  If you change to a lunchbox or pods you need the breather filter. Some people have used a PCV valve
instead of the filter. I'm curious about the PCV set-up if anyone has tried it.

My carbs/engine are stock P-28. I think the top-end power is fine but the off-idle/low-end performance is pretty sad.
Changing to a 15T drive sprocket and unplugging the TPS made a big difference in that department.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: The Buddha on June 03, 2022, 05:19:15 AM
Quote from: GSinTN on June 02, 2022, 01:43:26 PM
Quote from: The Buddha on June 02, 2022, 07:09:37 AM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
Quote from: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.

I will try it! My dumbass ordered 2 sets of jets....but only 1 jet each. Like i ordered 1 of each 20,62.5,65,142.5, and 145. Instead of 2. So when they come in i will install and then run without the line. Also, should i take the other off and see how it runs? Ive only had a gs500 for 2 months and its my first bike, so im new to the mechanical side of things. But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

What's worse is you didn't ask me for jets. Your setup and the jets you need are reaearched and proved out by O2 sensors.
142.5 is not one I have proved, but others here have tried it. 145 isn't needed for anything. 147.5 is a required size for WFO (K&N and pipe). And usually we do 20/147.5 in that case.
Cool.
Buddha.

I just went by the wiki "K&N Pod or Lunchbox Air Filter + Sports Exhaust = 20/65/145"

I have pilot/mid-main/ main jets on my bike.

Just got the k&n lunchbox and got a dominator gp1 exhaust on the way. My bike already had a really thin washer and a medium thickness washer on my carb needles.

What jets would you have selected differently with those mods?

K&N and pipe = 20/147.5/1 washer/3 turns. Well proven setup.
Mid mains are a "last resort" type of swap, my bikes ran great with the stock 60's. But to people in australia etc I recommend they get the 62.5's because if they needed it, its a long shipping time, so I would say get it just in case. You are right next door to me, you should be good with 20/147.5 and if you have the 20's already, I'll be happy to sell you just the 147.5's.
Cool.
Buddha.
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 03, 2022, 10:22:51 AM
Quote from: chris900f on June 02, 2022, 11:09:14 PM
The California code is P-33, the rest of the USA is P-03, Canada is P-28.

We all get the same jetting, and we all have the "pre-set" pilot screws. P-33's also get a leaner needle

The EU P-19's got the best set-up with a 135 main, a richer adjustable needle and adjustable pilot screws.

(https://iili.io/3WLDRR.png)


Also, re your last post if you keep the airbox you don't need a filter for the breather; just connect the hose
to the box.  If you change to a lunchbox or pods you need the breather filter. Some people have used a PCV valve
instead of the filter. I'm curious about the PCV set-up if anyone has tried it.

My carbs/engine are stock P-28. I think the top-end power is fine but the off-idle/low-end performance is pretty sad.
Changing to a 15T drive sprocket and unplugging the TPS made a big difference in that department.

Ive got a 14t front sprocket on so im excited to see how it performs with the new lunchbox and rejetting. So with your bike, you unplugged TPS, do you have any of those extra lines like the picture i showed in my first post?  And if you do, did you take off any of those lines once you unplugged TPS?
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: GSinTN on June 03, 2022, 10:30:07 AM
Quote from: The Buddha on June 03, 2022, 05:19:15 AM
Quote from: GSinTN on June 02, 2022, 01:43:26 PM
Quote from: The Buddha on June 02, 2022, 07:09:37 AM
Quote from: GSinTN on June 01, 2022, 07:28:24 AM
Quote from: The Buddha on June 01, 2022, 06:58:52 AM
Plug it, its just evap emissions crap.
Cool.
Buddha.

I will try it! My dumbass ordered 2 sets of jets....but only 1 jet each. Like i ordered 1 of each 20,62.5,65,142.5, and 145. Instead of 2. So when they come in i will install and then run without the line. Also, should i take the other off and see how it runs? Ive only had a gs500 for 2 months and its my first bike, so im new to the mechanical side of things. But do i even need the TPS on the bottom of the carbs? Almost all the lines lead to the TPS. And the EGR valve is useless because i dont have a airbox anymore. Basically i want to get rid of all the PAIR shaZam! and emissions shaZam!. Have you done that before?

What's worse is you didn't ask me for jets. Your setup and the jets you need are reaearched and proved out by O2 sensors.
142.5 is not one I have proved, but others here have tried it. 145 isn't needed for anything. 147.5 is a required size for WFO (K&N and pipe). And usually we do 20/147.5 in that case.
Cool.
Buddha.

I just went by the wiki "K&N Pod or Lunchbox Air Filter + Sports Exhaust = 20/65/145"

I have pilot/mid-main/ main jets on my bike.

Just got the k&n lunchbox and got a dominator gp1 exhaust on the way. My bike already had a really thin washer and a medium thickness washer on my carb needles.

What jets would you have selected differently with those mods?

K&N and pipe = 20/147.5/1 washer/3 turns. Well proven setup.
Mid mains are a "last resort" type of swap, my bikes ran great with the stock 60's. But to people in australia etc I recommend they get the 62.5's because if they needed it, its a long shipping time, so I would say get it just in case. You are right next door to me, you should be good with 20/147.5 and if you have the 20's already, I'll be happy to sell you just the 147.5's.
Cool.
Buddha.

When i get home im gonna take a picture of my needle. Its got 2 washers on it, idk if it comes stock with any washers but its 1 really thin one, and one i guess average thickness.

What would you charge to ship me 2 of the 147.5s? And also where can i get a full oring/gasket rebuild kit? My float bowl gaskets are starting to crack. And i have been too scared to mess with floats but i need to check my float needle. My old airbox looked like it was melted a little where it seats to my right carb. What could cause this? I was guessint maybe a oittle too much fuel
Title: Re: Do i need this vaccum line on top of diaphram?
Post by: chris900f on June 03, 2022, 02:56:39 PM
Quote from: GSinTN on June 03, 2022, 10:22:51 AM
So with your bike, you unplugged TPS, do you have any of those extra lines like the picture i showed in my first post?  And if you do, did you take off any of those lines once you unplugged TPS?

I just unplugged the TPS and left everything else in place.