Need Expertise on Rubber Softeners

Got my new ones in, and boy are they soft!! I didn't realize how hard the others had become. Still gonna test the old ones with suggested stuff, so we will be Subject Matter Experts (SMEs) for anyone else reading this thread.

Thanks for all of the helpful participation!

This is an old thread, but I thought I'd report on what I've done.

I tried several different products to soften the carb boots on my kz750. The only one that helped a litte was the power steering fluid.

So I wasn't looking forward to putting them back on when I remembered someone mentioned putting them in hot water to soften the boots. Set up my little single burner in the garage and heated up some water to just below boiling.

Man, did it work :woohoo: In less than a minute the boot was soft (or softer) then brand new. It took a little practice getting them on, but I would usually have about 3-4 minutes before they started to stiffen again. Found that feeding them in from the airbox, pushing them almost all the way through, fitting them around the carb, then pushing them gentle back into the airbox worked best.

One of these days I'll buy new ones, but for now this works great!

flht1997 wrote:

if you are talking about the air cleaner to carb boots. i have alway just boiled water and plopped them in for a minute. it will give you about three minutes of working time. wear gloves cause they will be hot, but the come out like rubber bands.
i do not think there is something that will permanently soften them back up.

True. There are solvents that will strip the top layer of hardened rubber off, but it won't reverse the aging process. The stuff we used on turntable and VCR belts was called "rubber renue" or something like that. You could wipe rubber parts with it and it would take off the hardened surface and expose some softer rubber.

i put rubber parts in ziplock bags full of armor-all after i clean them up and let em sit,sometimes for months just keep topping off the armor-all.works really good on smaller partsB)