1979 GS550; Are these CV or VM carbs?

[Laz]

Sorry about creating a new topic, I searched for weeks, even used the google images AI tool to try to find what type of carburetor I have. This is my first motorcycle, and I've been fixing it up. Really fell in love with the bike.

I recently bought these upon recommendation by Urban Monk TV, and after struggling to get the Carb's back in with the airbox.
Amazon.com: UNI Foam Pod Filter Set - 39mm - Fits Honda CB500 CB550 CB750 Fits Kawasaki & Suzuki : Automotive

I assume I will need to rejet if I run pods. How do you go in upgrading a size for jets? Is there a formula you guys use to learn this?

Thanks!

[Laz]

IMG_20240308_181251_MP (1) (1).jpg



Adding a second picture to help identifcation.

[Nessism]

Urban Monk TV?

Those are VM carbs.

https://gsarchive.bwringer.com/mtsac/~cliff/storage/gs/GS550_77-82_all.pdf

https://gsarchive.bwringer.com/bikecliff/images/vm_carb_rebuild.pdf

It's far easier to use the stock airbox, compared to using pods and rejetting. If you insist, hit up member Zed for a set of "air correction jets". They are the cheat code to easy re-jetting with pods.

[93Bandit]

Urban Monk TV?

It's a small YouTube channel. The guy who runs the channel had a Cafe racer build series where he restomodded a late 70s GS550 if I recall correctly. He made a few references to the GSR and I think he joined the forum at the time to get some questions answered. I stumbled across his channel somehow when going down the YouTube rabbit hole one evening.

[unfocused]

You don't need to rejet with pods... You need air correctors as shown in my pic.

These control the air flowing into the emulsion tube. In my case, without them I would foul plugs in a couple of miles unless you rode wide open.

I have these installed on my Stock GS1000 - electronic ignition, modified air box and exhaust with VM26's.

My carbs are stock aside from these air correctors. The bike is running rich so I will be rejetting DOWN.

*edit - I am sure if I tweaked the orfice size in the air corrector, I wouldn't need to rejet.

These are the Kawasaki single screw carb's and with the air correctors installed, she runs completely normal - before install, I couldn't accelerate at all.

FTW - NO drilling required - just tap the hole for threads and install. I recommend you use a thread locker of your choice - blue is fine

*edit - CV carbs use the same principle but the air correctors are placed under the diaphragm



Carbs 1.jpg

[Laz]

You don't need to rejet with pods... You need air correctors as shown in my pic.

These control the air flowing into the emulsion tube. In my case, without them I would foul plugs in a couple of miles unless you rode wide open.

I have these installed on my Stock GS1000 - electronic ignition, modified air box and exhaust with VM26's.

My carbs are stock aside from these air correctors. The bike is running rich so I will be rejetting DOWN.

*edit - I am sure if I tweaked the orfice size in the air corrector, I wouldn't need to rejet.

These are the Kawasaki single screw carb's and with the air correctors installed, she runs completely normal - before install, I couldn't accelerate at all.

FTW - NO drilling required - just tap the hole for threads and install. I recommend you use a thread locker of your choice - blue is fine

*edit - CV carbs use the same principle but the air correctors are placed under the diaphragm



Carbs 1.jpg

Thanks for the response. What tap did you use to tap the holes for the air correction jets? Is there a guide for the air correction jets? I have some coming in from Zed, and have been looking for installation information

Sorry, I'm actually a plumber and have threaded pipe, but I haven't used a tap since working in a factory when I was 18.

Thanks!

[unfocused]

Thanks for the response. What tap did you use to tap the holes for the air correction jets? Is there a guide for the air correction jets? I have some coming in from Zed, and have been looking for installation information

Sorry, I'm actually a plumber and have threaded pipe, but I haven't used a tap since working in a factory when I was 18.

Thanks![/QUOTE]

Soft metal, real easy to tap. You will need to internally thread the needle jet air bleed in the mouth of each carb 8mm deep with an m5 x 0.8mm tap.
I set my correctors flush with the face of the carb.

And if you're in Cape Coral and need some help, hop over to St. Augustine to come see the Ride Into History motorcycle show and I can assist with the install.
The carbs need to be completely dissasembled because of metal chips and salsa :-)

[zed1015]

Here's a link to the Air corrector/ Choke plunger thread that has all the info you need.
MIKUNI Choke plunger seat replacement and Air corrector jets for GS fours VM's - The GSResources Forums
I also sent a reply to your PM this morning containing the same information.
Also i do not recommend using thread lock on the jets.. Just nip them up firm but lightly..