Another carb installation problem

[Guest]

I've now spent three hours in 85-degree heat trying to install the carbs on my 1980 550E. Here's the current status:

I can get the carbs into the engine-side boots no problem. But if I put them in all the way and tighten the clamps, I can't get the airbox boots on all the way.

If I pull the rack back a little (but still in the mouth of the engine-side boots), install the airbox boots and tighten those clamps, when I push the rack forward to seat the carb boots the airbox boots slip off. This happened twice - once when I pushed forward on the carbs and once when I pushed on the airbox. I could see the airbox boots slipping off as the carbs sat in position. This is with the airbox boot clamps tightened all the way.

What am I doing wrong, and how do I do it right?

Thanks.

[Octain]

Install the airbox before the carbs.

[snicrep5]

your not the only one. I thought id just pop in the airbox, boy was i naive. i tried as per the book, that didnt work. i tried it every other way possible. tore an air box sleeve. my problem may be that my airbox sleeves are too old and stiff. i have new carb boots. Im seriously considering going to pods now, also because if i have to dial in my carbs id have to take al that crap off again. and yeah it even hotter here (94 at 7 pm) and thaqt doesnt help.

[koolaid_kid]

I was able to patch this issue by disconnecting the airbox and connecting it to the carbs. Then I connected the carbs to the carb boots on the head. I found the true solution when I replaced all the rubber elements in the intake path. Much better, IMHO.

[TheCafeKid]

I've never worked on an 8v 550E model, but I have worked on a few L models and if they're similar the airbox seems like it was installed before the motor.
I'd suggest new airbox boots for starters. Not only do they get hard, bit they more or less seem to shrink back into the airbox some. In lieu of new boots, assure that the airbox is pushed all the way forward where it's supposed to be. If it's similar to the L, there are locating bolts that hold it in place on the frame under the seat/tank. Another thing, which will require a second set of hands. Remove the filter, and reach inside with a broom stick or something and push the airbox from the inside, they sometimes warp a bit, and then while the person is pushing the boots forward, tighten your clamps. Don't over tighten or they'll slide off.

[FiremanBob]

"Don't overtighten or they'll slide off." That may be the answer. I've been screwing the clamps down until their ends meet.

[hampshirehog]

New rubbers needed. Easy as pie when they're all buttery soft.

[ronzxcvb]

There are dots on the boots and the air box that need to be lined up
If the boots are hard or getting hard replace them
I had the same problem new boots for a 850gl was $60 from the dealer they just came in yesterday so hopefully everything will go back together now

[MisterCinders]

I think there was a thread in Tips and Tricks about wrestling the carbs and airbox onto this particular bike. Try a search in that forum.

[ChicagoBob]

I feel your pain. I had to do my 78 550 in January (in Chicago), when the rubber was hard as a rock. A heat gun and some lube helped. Also, make sure the airbox boots are rotated to the correct orientation, or they won't fit correctly on the carbs. the broomstick (or dowel) trick sometimes helps, too, but shouldn't be necessary if the boots are angled correctly.

It also helps if you are free to wiggle the airbox around as much as possible. I removed the battery, rear brake reservoir, the inner rear fender (pops out without tools), the airbox mounting bolts and the airbox top and filter, so i could get to every possible nook and cranny.

[FiremanBob]

Ok, got them on and everything is in place. I was able to start the engine and it both runs at idle and accelerates.

One more problem: When I start the engine, gas pours out of the carb bottoms on #3 and #4. What is this?

[hampshirehog]

Your floats are stuck or set too high. Try giving the bowls a tap - sometimes they just need that to unstick them.

[FiremanBob]

Thanks. A couple of taps with a 12mm flange nut wrench freed the floats. Bike is great now.

Turns out that not only was the tach drive gear toast, but the cable also. Have ordered one online after searching local dealers. It seems nobody stocks parts for older bikes any more. Thank the Deity for the interwebz.