Carbs Won's Seat Fully

[fatbiker]

With the help of people on this forum I've almost finished my 86 Vmax project. Bought her used in rough condition and now she runs great. Some of the time. The problem I'm having is that the carbs will not fully seat into the rubber boots. If I get one side to seat fully then the other side is sticking out. I've made sure that both sets of clamps are fully loose then used a rubber hammer to tap the carbs into the boots. At best I can get both sides in about 3/4 way on all 4 carbs but never will they all go in fully. After a good ride the carbs will begin to come out of the boots and the bike will bog down when I hit the throttle good and sometimes it feels like I'm running on three cylinders. Good, used boots and clamps were bought from Sean Morley so I know they're not the problem. I make sure to tighten both sets of clamps on each carb real good. The bike came with a set of carbs that were in bad shape and I had the same problem with them. The carbs that are on the bike now came from Captain Kyle so I doubt it's a misaligned rack although I can't rule that out. Any suggestions? The pics below are after 20 miles of riding.

 

[CaptainKyle]

I never had that problem when the carbs were on my bike. I am not saying they could not have been bumped around in Shipping & reinstalling. Have you tried putting a little silicone spray on the boots to try & get them all seated good. If your still having problems around the 2nd week of July I will be down there & will be happy to try & help you some & introduce you to some of the Houston Vmax group.

 

[fatbiker]

I don't think it's the carbs you sold me either as this same problem happened with the original set of carbs that came with the bike. I can get one side to seat fully but then the other side sticks way out. But never can I get both sides to seat fully at the same time. It's either one side or the other or I can get all 4 carbs to seat about 3/4 of the way.

I've met a couple of people from the Houston Vmax group but haven't attended a ride or meeting as the bike has not run 100% since I bought it. Every I fixed one problem another one would pop up. Would love to meet you when you come down so please give me a call when you get here!

 

[fatbiker]

Would someone please post a picture of their carbs similar to the ones I posted? Just where they seat into the boots. That will let me know if mine are in all the way or if they're not.

Thanks!

Fatbiker

 

[sdt354]

I would pull the carbs. install theboots on the carb and secure the upper clamps.
Like Kyle said, spray something on them to help them on. Are the boots hard as a rock? If so, you might want to consider new. Hot water can help soften them up,if no cracks. Mount the carbs and press then down into place till they all seat.
I hope this helps.

 

[davesax36]

They do have to go in level. Can't do one side then the other.

 

[one2dmax]

It should pop in one side then pop in the other just fine. They are a long way from being seated for sure. The clamps need to be pretty loose so the boots can expand and let the carb into place.

 

[fatbiker]

Boots are soft so they're not the issue. I've loosened the clamps as far out as possible and the carbs still won't seat fully. I've tried pressing in all 4 carbs at once as well as starting with one side then pressing in the other side. I can get one or the other side pressed in all the way but then the opposite side is partially in the boots. I would say it's a misaligned rack but it's happened with two sets of carbs in a row. The set that Captain Kyle sent me came off of his girlfriend (wife?) bike, into a shipping box, then straight onto my bike. I didn't touch them at all. I wonder if the intake is warped? I will try putting the boots on the carbs first then attaching the boots to the intake. Will let ya'll know how it turns out.

On another note, my problem with the engine running rough and feeling like it's running on 3 cylinders is not carb relater but electrical. Going to post that problem in the electrical section.

Fatbiker

 

[Mr. Max]

Put some WD-40 or similar to boots, they are snug fit and that should help a lot to pop them in place. Still needs a good push though! Also check that they are all right way in, I dont know that is it important or not, but there is differences on boot ends, other side has slots that fits to intake. On a picture that seems to be right way, I'm jus tossing ideers.

 

[Rusty McNeil]

Mine go in one side then the other every time,...Once I get one side mostly in I use a 2" x 4" or a 2" x 2' on the top of the carb and anywhere I can get on the frame to gently lever them down, not beating on them but levering them...no way in hell will mine go on with just a push....I think that's pretty normal from the ones I have worked on..

I used to use a rubber mallet and a piece of wood to soften the blow (repeated gentle taps really) but got worried about busting something.

There is not enough slop in the manifold bolt holes to let them be very much misaligned..I do not think it's possible...

Maybe the rack assembly is bent, but have never seen that happen either...

Any kind of grease on the boots will help too....

 

[jedi-]

If the old carbs were not sitting flat and the newer ones that you bought that were in good order and still not sitting correctly tends to suggest somethings not quite right.
With the carbs off, check the manifold heights to see if they're even. Don't know why they would be out but anything's possible I suppose.

 

[1st Shirt Maxer]

I have never had any of my boots off but is there a possibility that the carb boots that are on the intake are seated to far down? Putting the boots on the carbs as suggested previously would eliminate that possibility. If still having issues after checking that the only other things I would think of is either the intake is wrapper or maybe the wrong boots were installed (if that is even possible? Not sure if the top boots on the air box could be interchanged with the bottom ones but I would definitely look at that.

 

[fatbiker]

I'm going to remove the carbs and try putting the boots on them first then drop the assembly onto the intake. I did notice that the boots have slots that go onto the intake a certain way and I made sure they went on correctly. Will update later today. Thanks for all the suggestions so far!

Fatbiker

 

[one2dmax]

NOTE - there are bosses that will contact the boot when the carb is fully seated. Depending on which side you look at the carb from (like your pic 1 and pic 2).

 

[fatbiker]

I finally got the boots onto the carbs all the way and then the carbs with boots onto the manifold. Had to take the carbs off and bash the boots on with a rubber mallet. Even with the clamps completely loose they did not want to go on easily. Had to whack the carb assembly with the mallet to get the boot fully onto the manifold. I tightened the clamps and it's not going anywhere, ever! Amazing that you have to use so much force to get them seated fully. I'm betting that I was getting extra air into the intake and wasn't getting full performance from the bike. Once I get my electrical issue fixed (please see that thread in the Electrical section) I will sync the carbs and give you a report.

Huge thanks to all of you for the advice! I really appreciate it!

Fatbiker

 

[Fire-medic]

Having recently written to CaptainKyle, (thank-you for another question answered) I was working on the carbs and while I had recently purchased lower carb boots, I had not replaced the airbox-to-carb bellmouth rubber boots, and was having a time getting them to seat. They were tight in the airbox, but I could not get them to assume the position on-top of the carb bellmouths (closest to the air filter).

For removing the rack of carbs, Kyle had suggested using a stick under the front & back of the carb bodies & the valve covers as a fulcrum to loosen the rack of carbs from the lower rubbers, which worked great. Now I have a designated 'carb/wood dowel removal tool.' A broom handle by any other name works as-sweet.

Now it was time to replace the airbox.

So there I was trying to summon enough avoirdupois to work in-conjunction w/Mother Earth (gravity) to allow the airbox to pop-onto the carbs. It wasn't happening.

Now I am >200 lb. and can usually accomplish anything where bulk is an advantage, but I will never be able to follow Lawrence of Arabia and his camel through the eye of a needle. That would be a Brough act to follow.

Sitting there, next to my bike, wondering if it is time to use the "water test" as they did in colonial New England to discover whether or not a person was a witch, I was almost to the point of removing all those airbox rubbers and throwing them into the boiling water, to soften them up so I could then place them onto the carbs and let them cool/contract, solving my problem. I didn't want to go to the trouble.

Seizing on the moment, I decided that perhaps a more-direct application of force was in-order. I climbed onto the bike, after positioning the airbox directly-above the carb tops. Now I was standing on the footpegs w/the bike on its centerstand (you Kerker 4/1 guys will have to use a rear trackstand). I carefully positioned one foot at a time onto my case guards while holding-onto the handlebars. Then I sat onto the airbox lid and had the most-gratifying "plop!" as the airbox dropped about 1/2" neatly onto the carbs. "Mission accomplished!" Now tighten those clamps and you might as well check the clamps under the carbs too.

The summation:
Airbox loose? "Sit on it." And try to avoid 'methane blow-through.' It is flammable, and you don't want to cross the explosive threshhold, so put down the Marlboro, man.

http://www.vmaxforum.net/showthread.php?t=21303&highlight=Carb+boots

 

[johnblaid]

I am rebuilding a 1986 also. Buy new boots and clamps. I spent about 500 on new hoses, air box parts, and other stuff to rebuild it so it fits right and so nothing leaks vacuum.

hold your nose and spend like there's no tomorrow.

because there isn't

 

[leroycp]

+1 and use silicone grease (tube). Off...pry as above and on, with clamps fully loosened and silicone grease applied, press firmly then one side and then the other. With new boots you can both hear and feel it "pop" into place. I have, with older boots, which tend to dry, used a small 2X4 on top of the rack and a mallet. They do have to be level prior to install and use towels in each carb to prevent something from being knocked loose and dropping inside. Buy new boots. (all)

 

[MANA1]

My 2¢, I used to have a hell of a time getting the carbs to seat. If your carb rack is tweaked you will have a gap between the boots and carb and possibly damage the carb bodies by pounding on them (did that). I always place the carbs on a level surface and adjust the carb rack by tightening the bracket screws a little at a time. A small level placed on top of the carb throat #1 & #4 then across #2 & #3. Once level you'll find that the carbs will seat itself with just the force of your weight pushing down.

 

[one2dmax]

Some guys have more "weight" then others!