Bonneville America Forums Forums Technical Forums General Tech re-rubberizing old rubber

I have a very old bike (88). The rubber boot that connects the carbs to the airbox is hard as a rock. It took me 2 hours just to remove the carbs because the rubber was so hard that it would not “smash” or bend to allow the carbs to move at all. Now I can not get the carbs back in. It is on a Jap bike and there is no room in there to move the air box or anything. Well to make a long story short I need to make the rubber boot soft again so that I can reinstall the carbs. Does anyone have any ideas???

Since it's just dry rot, maybe some oil-based liquid applied to the stuff might re-moisturize. Maybe a little neatsfoot oil, but truthfully this is all stab-in-the-dark advice, might be better off with new manifold boots.

I was going to buy new boots. But I am fixing this for my wife. She wants a Triumph! Cuz mine is cool. She has never ridden before so I figured that I had this old crapy thing out there for her. Just needed cleaned up a bit. She will ride it for about 1 month and then go buy her a new TBA. I dont want to put alot of money into this bike cuz she will dump it many times before she gets it right. So I am just looking for a cheep fix

If you're just gonna use it for a little while, then just dunk the parts in some motor oil for a few days. That should soften them up. They may not last long, so ride fast and sell it quick, to someone you don't know.

Yeah, I do think that if you're going to keep the boots, that applying something petroleum-based would be your best bet, the thinner the better though.

Thanks guys I will try that

I recently had the same problem with my trumpy,my advise would be toss them away and get new ones,they don,t cost much.I wasted untold hours trying to reuse mine,is it worth your sanity?

Now this is funny because when we were talking about carb vacuum caps drying up you were saying petrolium based stuff will degrade rubber... So are you thinking REALLY short term here guys?

That would be REALLY short term. Kinda like the old sawdust in the trans trick, or the crankcase full of STP. It's not a fix, just a bandaid to get rid of it. Somewhat unethically, I might add.

Hey guys ... what about some of these products you can add to your engine or transmission that are supposed to soften the seals to stop leaks. I've never tried any of them so I don't know if they work or not, but they shouldn't harm the rubber and they may soften it a bit.
Just a thought.

I used to use brake fluid (DOT 3). Your carb connectors may be beyond help, but it's worth a try. Let them soak for a day or two.....

PD,
I was going to suggest the brake fluid trick also, but I don't know if Dot 4 would have the same results. We used to use brake fluid to shine up the tires on our cars. Supposedly, after time, it would leach all the stuff out of the rubber that allowed it to flex, then cause cracks and extreme dry-out. I never owned a set of tires long enough to see if that was true, however....