1981 GS650 Carb and airbox frustration

[Guest]

How in the heck is one supposed to reinstall the airbox to carbs? This is so tight! It looks like the airbox needs to be in place first and carbs slipped or crammed into place. Then good luck getting airbox to carbs.
I'm tempted to remove and install individual KN's, but don't CV carbs have issues starting without airbox?
tx

[Nessism]

Yes, airbox must be in place before the carbs are installed.

After getting the carbs roughly in place, I suggest attaching the airbox to the carbs first, tighten the clamps, then showing the carbs forward into the boots attached to the head. Last thing is bolt the airbox to the frame.

Oh, and don't forget to replace the intake boot O-rings or you will likely be doing the job all over. Short cuts are long cuts when it comes to carb work.

[cowboyup3371]

Install the air box but don't tighten anything down just yet; slide it as far back as possible in the frame. Install the carbs from the right side connecting your cables before putting it completely in. After a few dozen choice words and angling down, the carbs will magically jump into the intake boots right about the time you break out the blowtorch. You'll have to move each airbox boot around the carb but will get it set so don't give up hope.

Then work on getting everything tightened starting from the airbox side first.

[loud et]

I just did this myself a few days ago. As has been said, carbs in from the right, hook up cables while carbs are just resting in the opening before hooking up. Remove the screws that hold the airbox to the frame. I think its 2 on the top and 1 on the side by the starter relay.
...now , one thing I have found is that the plasic airbox is prone to being flimsy and flexing backwards, making the middle boots very difficult.
My airbox had a concave shape to it across the area where the airbox boots go into it. Just this morning I removed the boots and used a heatgun on the airbox forming it to give it a convex profile(puffing out towards the carbs) as opposed to its former sunken in state. It cools down quickly and seems to have held its shape. Being a little more rigid and sort of pre loading it by it popping out should help it push onto the carbs instead of caving in/pushing in.
You are more likely to get the outer boots on first and then have to pry and convince the boots onto the middle carbs.
Its a bear, I know. I also wish the flange on the intake side of the Mikunis was about 1/4 inch longer to have more clamping surface. It stinks when you get it on then the clamp pops off right after you swear you have gotten it. Good times.

[exzachtly1]

I just did this myself a few days ago. As has been said, carbs in from the right, hook up cables while carbs are just resting in the opening before hooking up. Remove the screws that hold the airbox to the frame. I think its 2 on the top and 1 on the side by the starter relay.
...now , one thing I have found is that the plasic airbox is prone to being flimsy and flexing backwards, making the middle boots very difficult.
My airbox had a concave shape to it across the area where the airbox boots go into it. Just this morning I removed the boots and used a heatgun on the airbox forming it to give it a convex profile(puffing out towards the carbs) as opposed to its former sunken in state. It cools down quickly and seems to have held its shape. Being a little more rigid and sort of pre loading it by it popping out should help it push onto the carbs instead of caving in/pushing in.
You are more likely to get the outer boots on first and then have to pry and convince the boots onto the middle carbs.
Its a bear, I know. I also wish the flange on the intake side of the Mikunis was about 1/4 inch longer to have more clamping surface. It stinks when you get it on then the clamp pops off right after you swear you have gotten it. Good times.

Hah, I JUST did this too. Here is the thread. I used a hair dryer and it worked OK - but I will probably be pulling the carbs again soon to check some things so it may be time to invest in a heat gun. The hair dryer didn't quite get the plastic hot enough to do any serious reshaping, but it helped.

[loud et]

I guess it was worth a try, I am dipping the carbs now, so I wont be reinstalling for afew days. Not like it makes the airbox just "fall right on" , but ANY help is worth trying. Stupid airbox donuts.

[1_v8_merc]

Some airboxes like the 82 650G, have a big oval hose clamp between the Bootbox and the "actual" Air filter housing box, behind it.. If you loosen this, you can easily gain 1" of clearance, depending on where it was clamped at.