Carb Airbox boot alignment

Posted: Tue Jun 05, 2018 5:27 pm

I have removed and installed carbs many times... and everytime (after time passes) I always find myself trying to line up the airbox boots so they align with the carbs... Is there a mark somewhere on boots and airbox that shows where they should be?

Thanks
Vince

Posted: Tue Jun 05, 2018 6:05 pm

From what I have experienced, the carbs need to be bolstered upward after they're pushed into the inlet isolator rubbers first. This puts them in the right location for the airbox to just pop on nicely. Then the airbox needs to be pushed all the way forward and the top bolt tightened at that position.

Posted: Tue Jun 05, 2018 6:44 pm

Are you saying that your air box boots have rotated a bit? If that's the case, then they have to be realigned and glued back into place so they won't move. This is best done with the carbs and air box out of the frame. Also, I've found it easier to get the air box boots back on the carbs first. Tighten the clamps, then slide the airbox and carbs forward as a complete unit, and into the intake boots.

Posted: Tue Jun 05, 2018 7:21 pm

Tom, on a 750, I don't think you have that luxury of enough space. All the 750's I've worked on have less space behind the airbox and will not allow it to slide back as far as on a 900F. Maybe they've all been mismatched parts? But they looked pretty bone stock to me...

Hawk Joined: Jun 05, 2017 Posts: 330 Location: New England

I was searching the board and did see a post that said there were alignment marks on the airbox and boots, but cant find that post. I'm about to glue some new ones in myself.

Posted: Tue Jun 05, 2018 7:49 pm

I am also quite interested in this subject, as can be seen in the linked post!!!!!!!

Mike

http://www.cb1100f.net/modules.php?name=Forums&file=viewtopic&t=86452

Posted: Tue Jun 05, 2018 8:56 pm

Tom,

Yes when they get rotated... I always struggle getting them back right.

Vince

Posted: Wed Jun 06, 2018 1:08 pm

Loosen the battery box and inner fender, this allows the airbox to move back another 12mm or so.

Posted: Wed Jun 06, 2018 1:31 pm

toonces, great advice! That's really all it needs is that extra half inch (mm are confusing Smile

)

Posted: Thu Jun 07, 2018 5:20 pm

Thanks for the input... I understand why people go to pods... Carbs in out in no time. Airbox big pain.

Hawk Joined: Jun 05, 2017 Posts: 330 Location: New England

houredout401 wrote:

I was searching the board and did see a post that said there were alignment marks on the airbox and boots, but cant find that post. I'm about to glue some new ones in myself.

So I can confirm airbox boots and box have markings to line them up. Very small raised dot on airbox and a little rubber tit on the boot. I'm really glad I spent some time on this as not only did I discover a torn boot, but one was badly misaligned, another was not fully seated in the airbox. You really have to work the boot into the hole to get it to seat on the edge of the box properly.

I also see why they say NO PODS on these bikes. Definitely a delicate pressure balance created by that airbox set up. For several months I have chased carb issues and had trouble synching carbs, either getting them all even, and getting them steady. With a re-sealed and properly set up airbox, the carbs synched up very easily, evenly, and the gauge was not jumping all over the place.

Also confirm that with rear fender and battery box moved back, the carbs slip right in, no wrestling at all. Definitely worth the 15 minutes to undo fender and battery box.