How to keep engine rubber parts in good condition?

[roeme]

I read enough stories/projects/services in here where for example the inlet boots were hard/brittle/fell apart.

Mine are still good, and I'd like to keep them that way. Any recommendations?

I do have some glycerine, but I'm not sure if its any use on inlet boots.

[Burque73]

It seems the rubber will eventually harden but keeping it out of the sun will prolong the life of rubber parts.

[alke46]

I would recommend the use of 70% xylene and 30% wintergreen oil mixture if you are going to have the rubber parts off the bike for a while. A soaking in this solution will freshen up the rubber making it like new again. Nice and pliable.

[roeme]

I would recommend the use of 70% xylene and 30% wintergreen oil mixture if you are going to have the rubber parts off the bike for a while. A soaking in this solution will freshen up the rubber making it like new again. Nice and pliable.

I heard of this wintergreen oil a few times now. It seems specific to the NA market, I couldn't find reliable information on an equivalent product on my continent.

What's this Wintergreen oil?

[alke46]

www.BulkApothecary.com this should get you the information on the stuff.

[roeme]

www.BulkApothecary.com this should get you the information on the stuff.

Thanks! That helped. It's called differently ("Salicylsäuremethylester") around here, but interestingly, it's sometimes directly translated informally.

Huh. One of the pharmacies in town will have fun soon. Will be a nice change from the usual cough drops etc.

[alke46]

There seems to be two different grades of this stuff. One is therapeutic grade and the other is a commercial grade. Big price difference in the two with the commercial grade being least expensive and will work just fine.
Looks to be available in local pharmacies but I got mine online. If I remember correctly, the therapeutic grade was like $60 a 16 oz. bottle and the commercial grade was in the $20 / 16 oz. bottle price range.

Good luck.

[tkent02]

Go easy on the stuff. Don't leave them in it too long. The rubber parts will swell up much bigger than they should be, but in a few days they will shrink back down to the correct size, and they will remain soft.

[roeme]

Go easy on the stuff. Don't leave them in it too long. The rubber parts will swell up much bigger than they should be, but in a few days they will shrink back down to the correct size, and they will remain soft.

Will do. Thanks a bunch for the heads-up.

The airbox manifold boots did indeed act up a little yesterday when putting carbs back on (granted, it's not exactly a delicate operation on the 550s, even with the airbox detached from the frame), so these will surely take a bath the next time the carbs come off.

[jsandidge]

Go easy on the stuff. Don't leave them in it too long. The rubber parts will swell up much bigger than they should be, but in a few days they will shrink back down to the correct size, and they will remain soft.

They will also smell minty fresh for a long time.

[Hinermad]

It's called differently ("Salicylsäuremethylester") around here

Methyl salicylate. It's used in ointments and lotions for sore muscles. (Ben-Gay, Icy Hot, etc.)

I saw a guy on Youtube who recommended wiping down the inside of intake boots with Marvel Mystery Oil to keep them pliable. But I haven't tried it. Thoughts?

[roeme]

It's called differently ("Salicylsäuremethylester") around here

Methyl salicylate. It's used in ointments and lotions for sore muscles. (Ben-Gay, Icy Hot, etc.)

I saw a guy on Youtube who recommended wiping down the inside of intake boots with Marvel Mystery Oil to keep them pliable. But I haven't tried it. Thoughts?

Well, quoting wikipedia:

According to an NTSB post aircraft accident investigation published in 2003, a Marvel Mystery Oil sample tested was composed of 74 percent mineral oil, 25 percent stoddard solvent, and 1 percent lard.

I have no idea if this solution has the same effect on the rubber as the one recommended by alke and tom. Gut feeling says no.

The only thing I can imagine this coating does - or the user intends -, is to "seal" the rubber somewhat against the gasoline/air mixture passing it. But to be honest, I don't think a coating with the quoted ingredients would last very long against gasoline.

Gasoline "dissolves" Oil, doesn't it?

[tkent02]

All of that chemical stuff is way over my pay grade, but the boots I did a year or so ago with 50 / 50 mix of Wintergreen Oil and Xylene are still doing well. Still soft and supple, carbs went in and out yesterday with no problems. They don't smell any better or worse than any other old rubber anymore, just like your average old motorcycle parts.

[charlesandhisbeard]

cover the whole bike in wd40 or rp7. except the tyres and seat or youl fall off and get a smelly arse. seems to keep my rubbers good.

[tkent02]

cover the whole bike in wd40 or rp7. except the tyres and seat or youl fall off and get a smelly arse. seems to keep my rubbers good.

WD-40 on your rubbers? I would have thought that would sting.