How to: Fix cracked manifold boots with bicycle tube.

I needed this done, so I figured I'd post some pictures of how it went. I bought a Bell 16" tube for $5 at K-Mart. It was a really tight fit, so a 20" tube should work too. As you can see I used blue RTV. If you can, use the black RTV that fuel won't disintegrate.

1. Stretch a section of the rubber tube over the boot past the end.

2. Roll it up like a condom and lightly smear some RTV.

3. Roll it back down.

4. Repeat 2 & 3 for the other side of the boot.

5. Trim off the excess rubber and wipe off the extra RTV.

 

Wow save for the mentioned blue instead of black that looks very good. I imagin once you clean up the excess unless someone is really looking hard nobody would ever know the difference. Even more amazing you actually got the bolts out wihtout breaking any!!! That is my biggest worry on the boots and the Exh. as eventually they both need to come off. The boots whenever they fail and the pipes cause you just can't get in there to clean on the maxim X.

 

Interesting. Post up in a few months and let us know how it holds up.

The only concern I have is how well the tube rubber will hold up under heat but that could be just my paranoid nature...

 

Mr. hands is pretty smart! :lol:

 

The Florida sun (yes it's ours!) will kill those in 2 years, but that's a nice fix !!

 

Yup, bike tubes probably don't have any UV inhibitors mixed in with them, so they'll go quick in the sun.
On the other hand, great idea! I imagine the compressing action too will do a lot to prevent air leaks.

Maybe this in combination with one or two hits of black automotive primer to give it a little more life??

 

PS - I shouldn't talk, I'm afraid to touch those bolts because of all of the horror stories... Good for you for getting them off

 

The boot came off really easy. In fact, all four were pretty loose so I tightened them up a bit. The one that was cracked had the lower bolt broken off and re-taped from the previous owner.

Just an FYI, if you want the air cleaner boots more flexible, put them under a 60 watt work light for about 15 minutes. It softens them up and makes for an easy install.

 

Re: UV lighting. What if you did this then coated the whole thing with a dose of liquid electrical tape? Doesn't that have a bit of UV protection in it? That way you get the good seal and some additional protection... just a thought ;-)

 

I guess once you have them off and done, you could shoot them with Truck Bed Liner paint and have a nice wrinkle finish that would not transmit any light. And further disguise the repair.
Just remember that the boots underneath will continue to decay !!

 

I like that Idea. There is also a spray on version of the tool dip stuff you put on tool handles.

 

Nice job and photos, Jeepin, but with 5 kids I chuckled over the rolling the condom comment.

Those boots are going to last and the temps aren't going to melt them. Bike tubes are butyl rubber (probably as good as the original boot stuff) and the hi-temp RTV will work so both can withstand the temps on the intake side of the head. Same for UV rays and butyl. I'm betting they last a long while.

 

This sounds great, but the pictures are gone. Anyone have other pics? If not, I'll take some when I do this soon.

Any objections to 20" tire, or is 16" better for having a tighter fit? If it's still snug, but not stretched as much, I would think 20" would be better. Any feedback on this? Would love to attempt next time I pull my carbs here soon, just to allay any concern that my tubes are cracking--they've got to start letting air in eventually, can't hurt to patch them before it's leaking.

Would just coating them in penetrating oil for the next few days every morning in evening help prevent the bolt-breakage people describe on those allen heads on the head there that hold the manifold/boot/joints in?

 

I like the idea of rolling the tube....I did it this way:

http://xjbikes.com/Forums/viewtopic/t=37200.html