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Silicone rocker cover gaskets

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RGM supplied me with some silicon rubber rocker cover gaskets some years ago. They have been great, not leaking a drop of oil. I removed the covers recently and I found that the gaskets were starting to disintegrate. I phoned RGM to order some replacements but was told that they no longer sell them as they had become too expensive. Does anybody know an alternative source?

Ta!

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Hi.

They would probably have been nitrile rubber - silicon rubber does not take kindly to mineral oil or petrol! Your best bet is eBay. I got some nitrile gasket sheet some years ago and used it on my Dommi. Don't get it too thick or it will spread and split - the remains of your old gaskets will give you some idea of the gauge you want.

Regards,

Ian.

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Previously mark_woodward wrote:

RGM supplied me with some silicon rubber rocker cover gaskets some years ago. They have been great, not leaking a drop of oil. I removed the covers recently and I found that the gaskets were starting to disintegrate. I phoned RGM to order some replacements but was told that they no longer sell them as they had become too expensive. Does anybody know an alternative source?

Ta!

mark.

i,ve been using them for years.i get them from Rocky Point Cycles in the usa. not bought any for the last three years. they were about 12 dollers per set. google them and order them over the phone. i also bough of them a mikuni carb kit 280 dollers. cheaper than here.but that was five years ago.

good luck... tony.

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Previously ian_allen wrote:

Hi.

They would probably have been nitrile rubber - silicon rubber does not take kindly to mineral oil or petrol! Your best bet is eBay. I got some nitrile gasket sheet some years ago and used it on my Dommi. Don't get it too thick or it will spread and split - the remains of your old gaskets will give you some idea of the gauge you want.

Regards,

Ian.

Thanks Ian - you were right - eBay for £7.25 a set.

Cheers,

Mark W

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Previously ian_allen wrote:

Hi.

They would probably have been nitrile rubber - silicon rubber does not take kindly to mineral oil or petrol! Your best bet is eBay. I got some nitrile gasket sheet some years ago and used it on my Dommi. Don't get it too thick or it will spread and split - the remains of your old gaskets will give you some idea of the gauge you want.

Regards,

Ian.

I think you will find that most silicone rubbers have the edge over nitriles as regards resistance to hydrocarbons.

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Hi.

These sites http://mykin.com/rubber-chemical-resistance-chartan http://www.shinetsusilicone-global.com/catalog/pdf/rubber_e.pdfmight be useful and shows(according to Mykin) that Nitrile is superior to Silicone regardsmineral oils and especially petrol. Having worked inlabs for 40 odd years I've tried all sorts and silicone rubber petrol pipeswere not one of my better ideas. Silicone rubber swell appreciably in contact with petrol and will split under pressure.If your oil gets contaminated with petrol it will affect silicone gaskets.

Regards,

Ian.

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It's a shame that RGM have stopped selling these as I have advocated them for a few years - they are made from 1.5mm sheet - Alan

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I find the gearbox ones handy, too. It's not unusual (thanks, Tom!) here for the gearlever to not act as hoped for when all is reassembled... so to quote Uncle Ernie: It's off with the covers and... fiddle about, fiddle about!

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nortonbits do rocker cover sets, and js norton in California do fibre reinforced silicone gaskets, very reusable.

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Make your own.

I reckon Viton though expensive is the best 1.5mm thick, from a failing memory shore hardness 70. 

 


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