Vm22(gs500/550)1978 carb question(new question about jetting and 4-1 exhaust)

[Kenny]

Hi. Look at the picture, the 3 pipes(one got a black thin hose connected) is told to me that they are air breathers. As i bought the bike partially torned down , where does these go to? Where to connect them. Thanks!!

F0B6E711-18E4-410C-95B4-8559542D2E37.jpg

[hampshirehog]

The hoses going to your carbs are:

Fuel line. Hopefully obvious, the fat hose that goes to the tee.
Fuel tap vacuum hose. I think its on #3 but can't remember. However, its the odd one out of the remaining 3 and its on the intake side of the carb slide.
The 'other 2' , a matching pair on the airbox side of the carb. These are the breather hoses and just hang over the top of the sides of the front (plastic bit) of the airbox.

Plus of course the 4 overflow hoses from the bottom of the float bowls.

[Kenny]

The hoses going to your carbs are:

Fuel line. Hopefully obvious, the fat hose that goes to the tee.
Fuel tap vacuum hose. I think its on #3 but can't remember. However, its the odd one out of the remaining 3 and its on the intake side of the carb slide.
The 'other 2' , a matching pair on the airbox side of the carb. These are the breather hoses and just hang over the top of the sides of the front (plastic bit) of the airbox.

Plus of course the 4 overflow hoses from the bottom of the float bowls.

Thank you so much, that was very helpful!! 😀

[Kenny]

New question: my exhaust is ok but could have been better, found a new kit that Marving sells: 4-1. As i understand i might have to put in another jets.
here is the thing on a list on this page the gs550e 1978 have mainjet with the size 80. Now my bike is a gs500e and when i opened the carbs for cleaning my mainjets were 85.
Now i asked someone and he claimed Suzuki used to restrict carbs with putting in a bigger jet but lowering the needle. Is this true??
will it be enough for me to raise the needle only? Will only ride with 4-1 exhaust, no pods but standard airfilter and box.

[hampshirehog]

With a Marving you'll be OK with standard jetting as long as you leave the airbox as standard.

[Kenny]

With a Marving you'll be OK with standard jetting as long as you leave the airbox as standard.

Thank you. Really appreciate the help as i am a newbie to bikes and fixing them. I used to have my father to help me but he got Alzheimer now so not much he can do anymore. Again, thanx!

[Big T]

The hoses going to your carbs are:

Fuel line. Hopefully obvious, the fat hose that goes to the tee.
Fuel tap vacuum hose. I think its on #3 but can't remember. However, its the odd one out of the remaining 3 and its on the intake side of the carb slide.
The 'other 2' , a matching pair on the airbox side of the carb. These are the breather hoses and just hang over the top of the sides of the front (plastic bit) of the airbox.

Plus of course the 4 overflow hoses from the bottom of the float bowls.

He is correct. The port with the black hose on it is the vacuum . Turn your carbs around and look in the intake side. See that hole?
The other 2 ports are the air breathers for the float bowls, so fuel level can change inside the bowls. You should attach a hose to each one and run it up and over the airbox, and down into space behind, for still air

[steveb922]

As per Big T above - "You should attach a hose to each one and run it up and over the airbox, and down into space behind, for still air"

You'll see two brackets on top of the airbox, that will help you do exactly this without any risk of squashing the hoses.

[Kenny]

Thanx for the confirmation guys!

[Big T]

Looking forward to seeing your handiwork, Kenny!

[Steve]

One more confirmation, based on your picture.

The hose is attached to the vacuum port that will go to your fuel petcock. It will open fuel flow when the engine is running.
The open port below the hose in that picture is the fuel supply. It attaches to the fuel port on the petcock.
As pictured, your carbs are numbered 1 through 4, left to right. The port on carb #2 is not visible in your picture, but the port on #4 is. Those are the vent ports that should have hoses attached that go to that rectangular loop on top of the airbox under the seat.

.

[Kenny]

One more confirmation, based on your picture.

The hose is attached to the vacuum port that will go to your fuel petcock. It will open fuel flow when the engine is running.
The open port below the hose in that picture is the fuel supply. It attaches to the fuel port on the petcock.
As pictured, your carbs are numbered 1 through 4, left to right. The port on carb #2 is not visible in your picture, but the port on #4 is. Those are the vent ports that should have hoses attached that go to that rectangular loop on top of the airbox under the seat.

.

thanks, highly appreciated 😀 this is why i love this forum as there are people here that actually know stuff. A great place to learn and get good advice.