77 Yamaha XS360 Airbox

[thejoshuatree21]

What's up guys. I'm very new to motorcycles and just picked up a 77 yamaha xs360. The guy I got it from said he rebuilt the carbs, but the carbs seem way out of sync. I know I need to get that taken care of first. I took them out and cleaned them.

My rpm's fluctuate at idle and don't go down after I blip the throttle. Only after i adjust the idling screw.

I am trying to put on the stock airbox, to replace the uni pods he put on, but cant seem to get it to fit over the carbs. Is there any sort of rubber boot that goes from the carb to the H-tube of the airbox so I can get this thing on? I'm assuming these carbs aren't the original ones since it doesn't fit.

If I can't get the airbox on with the current carbs, how do I go about adjusting the carbs for a new pod filter? He put duct tape surrounding the bottom base of the filter because he said it was getting too much air. What size jets do I need and how do I even tell what size jets are currently in it?

I appreciate it guys

 

[BBS360]

Sounds like it's running too lean with the uni filters on now. That duct tape was an attempt to restrict the air flow to compensate.
If the mixtures screws don't have an affect you might need to order different jets.
If you don't want to go back to stock I would keep the Unis. Once the carbs are properly adjusted you should see better performance with the Unis than pods.
I'm not knowledgeable enough there to make a jetting recommendation.

Stock setup would be carbs to H-tube, H-tube to filters/airboxes.
Keeping it stock, if possible, should theoretically eliminate jetting adjustments.

How about the picture of the carbs?

 

[xschris]

The xs360 uses a different different H-pipe than the xs400. So make sure you get the right one. Stock jets are 17.5 pilots 135 main and needle jet needle set at third clip from top. The xs360 carbs use a very specific pilot jet and NOT the same as the xs400 ones. I run xs360 carbs on three of my xs400's and use stock jetting even with K&N filters. The filters I use are designed to go on the end H-pipe. What exhaust are you using? Make sure to sync the carbs with a manometer and confirm you have the correct jets in it.

 

[Cam]

Newbie here. Working on '76 XS360. Starts and idles instantly. Will idle all day long. The second I open the throttle the engine spits and farts and won't rev past 3000 rpm. New points and condensers, bores deglazed and new rings, 140# compression LS, 150# RS. All carb connections are tight. Needles were in center groove, raised them up 1 groove. Correct #122.5 main jet. Aftermarket mufflers, have tried blocking the exhaust from them off to assure back pressure. Serious clamps to seal mufflers to exhaust pipes. Timing is dead on.

What am I missing?

dawglakecam@gmail.com

 

[BBS360]

Correct #122.5 main jet.

Where'd you find this information?

 

[xschris]

On all the xs360 sets of carbs I have taken apart they are all 135 mains.