Wuzzup with carb boots shrinking?

I just don't get it. They were on the bike for what, 30 years? Now off the carbs for three months and suddenly they are too small in diameter to go back on over the carbs? What the hell is that all about? I don't want to buy all new for $80. Is there something that makes rubber swell? I know there is just can't remember what it was. Seems like if you put the wrong kind of tranny fluid in your car you would ruin all the seals. I dont remember all the details about that story.

Anybody out there help me out? They almost fit but don't. When the top and sides go on the bottom wont go on for nothing. Same thing if you start on the bottom. This is frustrating.

 

Heat gun will soften them up a lot. I thought it was brake fluid that caused rubber to swell, but that may increase the thickness of the material itself rather than enlarge the mouth of the boot.

 

Double-check the front of your airbox......often the airbox front will "sink" in the middle and keep the boots from reaching the carbs again. If that happened, then use the same hot air gun mentioned above and warm it up to flatten it back out. Otherwise, heat -em up and stretch -em out.

Now, two other thoughts........

1. If you've connected the the boots to the airbox and now you can't reach the carbs, have you loosened the retainers and slid the airbox all the way to the FRONT again?

2. I have also had success doing it this way........clamp the boots onto the carbs again, THEN attach the other end to the airbox. It's a little less convenient, but it's still a way around the problem.


dave

 

The rubber has lost its elasticity because of age and the elements. The carburetors were holding them in the stretched position, but they settled back after being removed. Now they're very hard (impossible) to stretch back over the carburetors.

Heating them a bit will make them more elastic. You can place them in hot water, but you have to work fast or they cool. If you go the heat gun route don't over do it and make absolutely sure there is no fuel or vapors to light off.

 

"Now off the carbs for three months and suddenly they are too small in diameter to go back on over the carbs?"
three months isn't exactly suddenly.
i revived some rubber enrichment plunger caps with a mix of that auto transmission seal swell and Berrymans carb cleaner

 

ok, now we're talkin here. cept for the heat gun thing. that didn't work at all, it was just too cold, (Edit: i was only using a blow dryer).. i pushed the bike out into the sun so it shone on the front boots. i even tried a portable elec. space heater and it didn't seem to do squatdiddly. i will get some brake cleaner first (cheapest), then seal swell, then the more expensive mix. this aint gonna be like cleanser and ammonia is it? haha. NOTHIN FUN about working with old ass rubber stuff.

 

i was all set to do the boiling water trick but i cant get them out of the stinkin air box, they are just too long inside there.

 

Push them out through the front of the airbox; that's the direction from which they were installed at the factory.

 

well yeah, that's the direction i am trying to pry them out of. They are just so long, and unbendable, that i cant get them out and am afraid i will rip them right in half they are so stiff. i will have to get a heat gun just to get them out. i have pryed on them with a screwdriver stuck in from behind, but it seems almost like the bottoms of those rubber boots is plastic it's so hard, it wont bend to come out of the hole. i am still hoping to reuse these, maybe that's a mistake, cause if i am not worried about destroying them i can obviously cut them out of there.

 

i think someone found a rubber plumbing connector that connects pipes, that can work for those. furndy or firmby or furry or something like that. take some measurements and a ride to the hardware store

 

i saw some thread yesterday about that and apparently it's not so hot for CV type carbs. They looked about ok tho, but they block some port i think, that the CV carbs need to run right.

 

i posted this in this other thread here: http://www.xjbikes.com/forums/index.php?threads/fitting-carbs-im-bracing-myself.48202/

i just realized the only way to get them out was pull them out thru the airbox. posted my first pic there too. Seems like it will be easy to push them back in that way too. Now gonna save up to buy new ones. as these look like Slit.

 

http://xjbikes.com/forums/index.php?threads/awesome-alt-to-airbox-to-carb-boots.18757/

 

awesome. thanks. i owe ya. i was going to just stop dead in my tracks and maybe sell the bike. i need a battery too and dont have any money. i will try to keep the bike now. i only spent $500 on it with two new tires so i cant complain too much. needed paint, almost free, carbs cleaned out w/parts, spent $150, was supposed to run but you know how that goes. needs batt, license plate, insurance, and have to check rear brake. alittle duct tape on the seat tears. man i'm broke and this blows. but at least now i'm not having to drop another hundie on airbox boots!

 

well, i guess they are working on a different bike. they definitely will NOT fit on an '85 water cooled 700xj. here is a pic of why. they are actually way smaller than my shrunken old units and there is no way in HELL they are ever going to fit into my carb. i could not even get the small end to fit into my airbox hole. glad i didn't waste anymore time on this. got to get the ones from the Man. Unless somebody can think of something i am doing wrong...i have been trying to push this thing thru the hole for about an hour. i cut the coupling in half for starters. Now it is about the same length as stock. so i have the lip for the hose clamp still on trying to shove that end in first, i want to know if the smaller diameter will seal the hole still, but i can't even get that little 1/8 inch lip to go thru the whole. I have been trying to push it OUT thru the airbox, in case you're not following. this blows, man. it seems like it ought to go in no problem. it's really soft rubber so i don't get it.