VM22 SS Carb jet needle sping loaded?

[Anonymous]

Hi everyone,

I'm rebuilding my carbs on my 1979 GS 550E. They are VM22SS models. Upon installing new jet needles, I noticed that the needle seems to be acted on by a spring. When I go to install the slide, the needle is not perpendicular to the needle jet. I must reach into the carb throat, bring the needle tip forward a bit then it will drop in. Is this supposed to be like this? It seems kind weird because in operation the jet needle will not be perfectly centered in the jet, rather drag along the back if it as it raises. Am I installing it improperly? Please help! Thanks
Jeff

 

[Anonymous]

Re: VM22 SS Carb jet needle sping loaded?

Hi everyone,

I'm rebuilding my carbs on my 1979 GS 550E. They are VM22SS models. Upon installing new jet needles, I noticed that the needle seems to be acted on by a spring. When I go to install the slide, the needle is not perpendicular to the needle jet. I must reach into the carb throat, bring the needle tip forward a bit then it will drop in. Is this supposed to be like this? It seems kind weird because in operation the jet needle will not be perfectly centered in the jet, rather drag along the back if it as it raises. Am I installing it improperly? Please help! Thanks
Jeff

WAS IT RUNNING BEFORE YOU TOOK THE CARBS APART?? AND ALSO DID YOU INSTALL THE TOP AFTER YOU CENTERED THE NEEDLE TO SEE IF IT CAN BE SLID UP AND DOWN BTW I DONT THINK THE NEEDLE COMES ALL THE WAY OUT OF THE SEAT EVEN WHEN WIDE OPEN--BUT NOT SURE-SIT TIGHT THE ANSWER WILL FOLLOW FROM THE MORE EXPERIENCED

 

[Don Lobacz]

Yes, that is the normal operation for most of the VMs. There is a spring in the slide that the needle rides on. There are a few VMs that don't have the spring. Did you put the big and small plastic washers back on the needles in the same way (big on top)?

 

[Anonymous]

The bike was running when I pulled the carbs out (although rather rich). As near as I can tell the carbs have never been apart before but I can't swear to it. The rebuild kits are from Keyster and include new needles, that's how I came to take apart the slider. There is a small plastic washer that sits on top of the needle position clip but no second other washer. Any other carbs I've worked on, the jet needle is loose so as to automatically center itself in the jet. I think the theory is that under vacuum, the needle will stay centered because the force of the fuel being drawn up is equal all around. The way this is set up, it seems the back (intake) side of the needle will be in contact with the jet throughout it's motion. Wouldn't that affect mixture and ul;timately wear out the needle and jet because of the physical contact? Anyone know of a good vm22ss diagram out there?

 

[Anonymous]

The bike was running when I pulled the carbs out (although rather rich). As near as I can tell the carbs have never been apart before but I can't swear to it. The rebuild kits are from Keyster and include new needles, that's how I came to take apart the slider. There is a small plastic washer that sits on top of the needle position clip but no second other washer. Any other carbs I've worked on, the jet needle is loose so as to automatically center itself in the jet. I think the theory is that under vacuum, the needle will stay centered because the force of the fuel being drawn up is equal all around. The way this is set up, it seems the back (intake) side of the needle will be in contact with the jet throughout it's motion. Wouldn't that affect mixture and ul;timately wear out the needle and jet because of the physical contact? Anyone know of a good vm22ss diagram out there?

Actually you willhave to put them back on the bike to tune them. the mid range needles usually can be gotten to without removing the carbs--does your rebuilding kit have needles that are adjustable??

 

[Anonymous]

First of all the diameter of the hole and the diameter of the needle determine the area available, and the needle doesn't have to be in the center of the hole to meter the same amount of fuel. Area is area regardless.

Also, the needle is still likely to float about the centerof the hole because the velocity of the fuel will force it to the center. The spring action isn't that strong. Not to worry, mine was the same and I didn't take these apart when I rebuilt mine, just polished the needles and the slides to get any gum residue off.

Roger